HS2.3.8 | Fate and transport processes of pathogens and emerging contaminants at multiple scales
Fate and transport processes of pathogens and emerging contaminants at multiple scales
Convener: Julia Derx | Co-conveners: Sondra Klitzke, Margaret StevensonECSECS, Fulvio Boano, Yakov Pachepsky, Matthias Gassmann, Felicia LinkeECSECS
| Tue, 16 Apr, 14:00–15:45 (CEST), 16:15–17:55 (CEST)
Room 2.44
Posters on site
| Attendance Mon, 15 Apr, 10:45–12:30 (CEST) | Display Mon, 15 Apr, 08:30–12:30
Hall A
Posters virtual
| Attendance Mon, 15 Apr, 14:00–15:45 (CEST) | Display Mon, 15 Apr, 08:30–18:00
vHall A
Orals |
Tue, 14:00
Mon, 10:45
Mon, 14:00
The occurrence of pathogens and of an exponentially increasing number of contaminants in freshwater and estuary environments pose a serious problem to public health. This problem is likely to increase in the future due to more frequent and intense storm events, the intensification of agriculture, population growth and urbanization. Pathogens (e.g., pathogenic bacteria and viruses, antibiotic resistance bacteria) are introduced into surface water through the direct discharge of wastewater, by the release from animal manure or animal waste via overland flow, or, into groundwater through the transport from soil, which subsequently presents potential risks of infection when used for drinking, recreation or irrigation. Contaminants of emerging concern are released as diffuse sources from anthropogenic activities, as discharges from wastewater treatment plants (e.g., trace organic contaminants, PFAS), or occur due to microbial growth (e.g. cyanotoxins), posing a burden on human health. So far, the sources, pathways, fate and transport mechanisms of fecal indicators, pathogens and emerging contaminants in water environments are poorly understood, and thus we lack a solid basis for quantitative risk assessment and selection of best mitigation measures. Innovative, interdisciplinary approaches are needed to advance this field of research. In particular, there is a need to better understand the dominant processes controlling fecal indicator, pathogen and contaminant fate and transport at larger scales.
This session aims to increase the understanding about the dominant processes controlling fecal indicator, pathogen and contaminant fate and transport at larger scales. Consequently, we welcome contributions that aim to close existing knowledge gaps and include both small and large-scale experiments, with the focus on
- the fate and transport of fecal indicators, pathogens, emerging contaminants including persistent and mobile organic trace substances (e.g. antibiotic resistance bacteria, cyanotoxins, PFAS) in rivers, soils, groundwater and estuaries
- Hydrological, physically based modelling approaches
- Methods for identifying the dominant processes and for transferring transport parameters of fecal indicators, pathogens and contaminants from the laboratory to the field or catchment scale
- Investigations of the implications of contamination of water resources for water safety management planning and risk assessment frameworks

We will organize a session dinner on Tuesday, 16.4. 2024 19:30 at Restaurant Mini (https://www.minirestaurant.at/). We hope to see many of the attendants there!

Session assets

Orals: Tue, 16 Apr | Room 2.44

Chairpersons: Julia Derx, Margaret Stevenson, Sondra Klitzke
On-site presentation
Scott Bradford

An understanding of pathogen transport and fate in the environment is needed to assess the risk of contamination of water and food resources, and to develop control strategies and treatment options.  This presentation discusses advances to better understand and predict the fate of pathogens in the subsurface at different spatial and temporal scales.   Adhesive interactions of pathogens with surfaces are demonstrated to be strong functions of nanoscale and microscale heterogeneities, interface geometry, and solution and solid phase chemistries.   Pathogen retention and release are shown to be sensitive to these factors as well as spatial variability in hydrodynamic conditions. Pore-network models have been used to account for retention processes, including attachment, straining, and hydrodynamic bridging.  Alternatively, machine learning algorithms have been trained on extensive databases to predict retention parameters.  Steady-state and transient release from episodic changes in solution chemistry and water saturation can greatly impact the long-term fate of pathogens. Ongoing efforts to account for governing physicochemical factors into continuum scale models at the column, hillslope, and watershed scales are highlighted. 

How to cite: Bradford, S.: Pathogen Transport and Fate Processes in the Environment at Different Scales, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-12868, https://doi.org/10.5194/egusphere-egu24-12868, 2024.

Virtual presentation
Liping Pang, Sujani Ariyadasa, Travis Issler, Beth Robson, Richard Sutton, Susan Lin, Panan Sitthirit, Elmar Prenner, and Craig Billington

By mimicking the physicochemical properties of important waterborne pathogens, we believe that synthetic particles can be used to predict water contamination risks in freshwaters and help to design improved water treatment systems and water-supply bore protections.

We have developed two generations of synthetic pathogen surrogates for water quality applications. The first-generation was based on biomolecule-modifications of commercially available microspheres and nanoparticles to produce surrogates for the pathogens Cryptosporidium, rotavirus and adenovirus. The second-generation is based on biomolecule-modifications of microparticles and nanoparticles that we have made from food-grade natural biopolymers to produce surrogates for the pathogens Legionella, Cryptosporidium and rotavirus.

The surrogates have closely mimicked the physicochemical properties (e.g., size, shape, surface charge, hydrophobicity) of the target pathogens. Experiments conducted have validated surrogates’ performance against the actual pathogens in different systems; the surrogates displayed the same order of magnitude removal as the target pathogens in different experimental conditions.

The first-generation Cryptosporidium surrogates were used in pilot-scale studies to evaluate the efficacies of protozoan removal by drinking-water filtration systems commonly used in New Zealand under typical operating conditions. These included testing rapid sand filtration systems at a water treatment plant in collaboration with the Invercargill City Council and domestic point-of-use water filters in a domestic plumbing test rig. The experimental findings were incorporated into quantitative microbial risk assessments. Health-risk scenarios were identified and recommendations for improving water treatment performance were communicated to end-users. Our experimental results have also highlighted that turbidity, a key test of water clarity and a proxy for water quality used by water plant operators, may not be a reliable indicator of protozoan removal.

Recently, we have advanced our pathogen surrogate technology by producing and testing a second-generation of surrogates that are more compatible with use in natural water systems. These surrogates, made from food-grade natural biopolymers, can be applied in operational water treatment systems and eco-sensitive freshwater environments. Our preliminary studies suggest that these new pathogen surrogates show great promise as new tools for water applications. We will conduct further validations.

We can label the surrogates with unique synthetic DNA sequences for tracking and detection purposes. Degradation of the surrogates’ DNA was found to mimic pathogen’s DNA degradation to some degree. The DNA-tagged surrogates, even at very low concentrations, can be analysed sensitively and rapidly using qPCR. Working with ECAN and Waikato Regional Council, we have validated DNA encapsulated biopolymer particles (as pollution source tracers) in surface water, groundwater and soils, and they were readily trackable in a surface stream for at least 1 km.

The surrogate technology approach has opened a new avenue for assessing pathogen removal and transport in water systems without the risk and expense that accompany work with actual pathogens. The research findings will facilitate improved management systems and engineering approaches to reduce waterborne infection risks and safeguard public health.

How to cite: Pang, L., Ariyadasa, S., Issler, T., Robson, B., Sutton, R., Lin, S., Sitthirit, P., Prenner, E., and Billington, C.: Studying pathogen attenuation and transport in freshwater systems using novel surrogate technology, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-4242, https://doi.org/10.5194/egusphere-egu24-4242, 2024.

On-site presentation
Friederike Currle, René Therrien, Théo Blanc, Yama Tomonaga, Rolf Kipfer, Daniel Hunkeler, Philip Brunner, and Oliver S. Schilling

Understanding microbial transport behaviour in river-aquifer systems is crucial for drinking water management. Particularly after heavy rain and peak flow events, the quality of groundwater pumped near streams might be impacted by high microbial loads. Dissolved noble gases have been shown to be conservative tracers of river-aquifer interactions and provide information on pathways and travel times of alluvial groundwater. However, due to size exclusion, microbes appear to travel faster than solutes and dissolved gas tracers might therefore not provide insights representative for microbial transport. Recently, online flow cytometry (FCM) has been shown to be a promising tool to track on site, continuously, and in near-real time the movement of microbes in riverbank filtration settings (Besmer et al., 2016). Beyond direct cell counting, unique microbial community patterns such as high (HNA) and low (LNA) nucleic acid content microbes, often referred to as larger and smaller prokaryotes, can be distinguished by FCM.

Aiming to identify preferential transport pathways of microbes and develop a quantitative tool for riverbank filtration site modeling, we combine online FCM and noble gas analyses with integrated surface-subsurface hydrological modelling (ISSHM). We use a dual-permeability approach with a two-site kinetic deposition mode which enables the co-simulation of fast preferential microbial transport and slower bulk transport, along with attachment and detachment of the microbes in high and low permeability regions of the pore space (after Bradford et al., 2009). The formulation was implemented in the ISSHM HydroGeoSphere (HGS; Aquanty, Inc.) and enables multispecies transport, e.g., to represent HNA and LNA groups.

An 8-month measurement campaign at a riverbank filtration site in Switzerland showed that cell concentrations and microbial community patterns are sensitive to surface water infiltration and travel distance in the alluvial aquifer. Distinctly different changes in microbial patterns could be observed for peak flow events, river restoration activities, and spring snowmelt periods. The observed reactive microbial transport behaviour was reproduced and quantified by systematic numerical experiments on the wellfield scale using the transport of conservative dissolved noble gases as a benchmark.

In summary, the interdisciplinary approach combining online flow cytometry, dissolved (noble) gas analysis and explicit microbial transport simulations with an ISSHM is a promising tool to understand and quantify the reactive transport of microbes from rivers into and through alluvial aquifers.



Besmer, M. D., Epting, J., Page, R. M., Sigrist, J. A., Huggenberger, P., & Hammes, F. (2016): Online flow cytometry reveals microbial dynamics influenced by concurrent natural and operational events in groundwater used for drinking water treatment. Sci. Rep., 6, Article 38462. https://doi.org/10.1038/srep38462

Bradford, S. A., Torkzaban, S., Leij, F., Šimůnek, J., & van Genuchten, M. T. (2009). Modeling the coupled effects of pore space geometry and velocity on colloid transport and retention. Water Resources Research, 45(2). https://doi.org/10.1029/2008WR007096

How to cite: Currle, F., Therrien, R., Blanc, T., Tomonaga, Y., Kipfer, R., Hunkeler, D., Brunner, P., and Schilling, O. S.: Tracing and quantifying microbes in riverbank filtration sites combining online flow cytometry and integrated surface water – groundwater modelling, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10537, https://doi.org/10.5194/egusphere-egu24-10537, 2024.

On-site presentation
Reza Ahmadian and Man Yue Lam

Contaminants in nearshore coastal waters have far-reaching public health and economic implications, such as contaminated food from aquaculture, reduced tourism, and the associated economic losses. The US marine economy annually provides 2.4 million jobs and contributes £312 billion (US$397 billion) to the country’s Gross Domestic Product. Domestic overnight trips to coastal areas in Great Britain contributed £4.6 billion in year 2022. Faecal Indicator Organisms (FIOs) are a class of contaminants that are highly correlated with illnesses such as gastrointestinal, eye, nose and throat infections, and skin complaints. FIOs are commonly used to indicate pathogen levels in waterbodies and have been routinely monitored in bathing water sites. Numerical hydro-epidemiological models have been developed for water quality prediction and management. FIO decay modelling is an integral part of hydro-epidemiological models to simulate the die-off of FIOs after they have been injected into the waterbodies. While the Stapleton et al. (2007) FIO decay model has been successfully applied for Severn Estuary and Bristol Channel, UK, this research identified two model limitations. They were: (i) the modelled decay rates for dark or highly irradiated environments are not accurate, and (ii) the effect of salinity is not included. The Stapleton decay model was modified by (i) imposing a minimum decay rate (ClipStap model); and (ii) extrapolating the decay rate-irradiation slope at a reference irradiation (260 W/m2) down to lower irradiation regions (ModStap model). The modified models were tested with a TELEMAC-3D hydro-epidemiological model for Swansea Bay, UK. Buoyancy effects due to the salinity difference between river fresh water and saline seawater have been included as the effects are found to be critical for FIO transport. The model was validated and evaluated against the water level, velocity, salinity and FIO concentration data obtained in the “Smart Coasts – Sustainable Communities (SCSC)” research project in year 2011 and 2012. Results showed that while the ModStap model successfully reproduced the reported dark decay rates in the literature, it did not always give better FIO prediction results. In addition, this research demonstrated that the observed diurnal variations of FIO concentrations are caused by the combined action of riverine FIO inflows, tide action, and FIO decay. Given the unsuccessful model prediction, the effect of sediment-FIO interactions (Huang et al., 2015) will be tested with the hydro-epidemiological model. These insights on the effect of irradiation, diurnal FIO variations, and sediment-FIO interactions on bathing water quality are critical for the management of coastal human activities, and nearshore ecology.


Reference: (i) Stapleton et al. (2007). Link: https://assets.publishing.service.gov.uk/media/5a7c5af4ed915d696ccfc370/scho0307bmef-e-e.pdf; (ii) Huang et al. (2015). doi: 10.1080/15715124.2014.963863


Keywords: Nearshore coastal waters; FIO decay models; irradiation; diurnal variations; hydro-epidemiological models; Swansea Bay

How to cite: Ahmadian, R. and Lam, M. Y.: Modified Faecal Indicator Organism (FIO) decay models for nearshore coastal waters, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-19314, https://doi.org/10.5194/egusphere-egu24-19314, 2024.

Part 2
On-site presentation
Xuneng Tong, Luhua You, Shin Giek Goh, Shimin Charmaine Marie Ng, Jingjie Zhang, Kyaw Thu Aung, Wei Ching Khor, and Karina Yew Hoong Gin

Predicting the transport and fate of antimicrobial resistance (AMR) in aquatic environments is crucial for managing this pressing environmental issue. We proposed a hybrid modeling framework that couples process-based and data-driven models to predict the spatiotemporal distribution of antibiotics and their related antibiotic resistance genes (ARGs) in Singapore's coastal waters (SCW). In this study, Lincomycin and its related ARGs were selected for analysis. Firstly, this study provides valuable insights into the complex dynamics of ARGs in coastal waters through the application of a meticulously constructed Random Forest (RF) model. This model helps identify key environmental drivers of ARGs, specifically Lincomycin, pH, zinc, DO and temperature, thereby illuminating the factors influencing ARG levels. Subsequently, we applied a process-based model using the Delft 3D suite to simulate the fate and transport of these key environmental drivers. Finally, the outputs from the process-based model were integrated with the RF model to predict ARGs. The modelling framework was calibrated and validated against monthly data collected from 12 sampling points around SCW during 2022-2023. The results revealed that the simulation performance provided 'reasonable prediction' results, with all modeled targets showing an R² above 0.7 and an NSE greater than 0.8. The research presented in this study not only enhances our understanding of the intricate interplay between environmental variables and ARG levels but also has significant implications for environmental and public health management. By emphasizing the importance of specific environmental factors, these models offer a proactive approach to addressing the urgent challenge of antibiotic resistance in coastal ecosystems. This ultimately contributes to the preservation of both the environment and public health.

How to cite: Tong, X., You, L., Goh, S. G., Ng, S. C. M., Zhang, J., Aung, K. T., Khor, W. C., and Gin, K. Y. H.: An integrated modelling framework to predict the fate and transport of antimicrobial resistance in Singapore coastal waters, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-16277, https://doi.org/10.5194/egusphere-egu24-16277, 2024.

On-site presentation
Ali Obeid, Thomas James Oudega, Ottavia Zoboli, Claudia Gundacker, Alfred Paul Blaschke, Matthias Zessner, Ernis Saracevic, Nicolas Devau, Margaret E. Stevenson, Nikola Krlovic, Meiqi Liu, and Julia Derx

Per- and Polyfluoroalkyl Substances (PFAS) are extensively utilized chemicals owing to their desired physicochemical properties. Despite increasing efforts to limit their applications, they persist in the environment and pose a threat to drinking water production due to their persistence, mobility, and toxicity. Understanding their behavior in subsurface media is crucial for minimizing the risk of exposure in areas where groundwater is a significant source. Sorption is considered a pivotal mechanism in PFAS remediation. This study aims to explore the transport behavior of different PFAS groups in soil sorption experiments and establish a connection to field scenarios.
Miscible displacement experiments were conducted on a mixture of PFAS. A 50 cm long glass column filled with sand was injected with a 2.5 µg/l PFAS solution. Subsequently, the column was flushed with a PFAS-free solution to examine the desorption process. A conservative tracer test was performed to determine hydrogeological properties. Samples were analyzed using liquid chromatography-mass spectrometry. Breakthrough curves were then simulated using Hydrus 1D to obtain transport parameters.
The results revealed that different PFAS groups exhibit varying orders of magnitude of sorption. Some were conservative, while others were entirely retained. In addition to functional groups and chain length, hydrophobicity played a crucial role in PFAS behavior. The desorption process was inversely proportional to sorption; less desorption occurred with an increased sorption level.
To simulate these behaviors, different sorption modules in Hydrus were tested. Substances with higher sorption levels required more complex sorption terms and could not be accurately simulated by assuming equilibrium sorption.

How to cite: Obeid, A., Oudega, T. J., Zoboli, O., Gundacker, C., Blaschke, A. P., Zessner, M., Saracevic, E., Devau, N., Stevenson, M. E., Krlovic, N., Liu, M., and Derx, J.: PFAS variable transport behavior: insights from soil sorption experiments, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-19365, https://doi.org/10.5194/egusphere-egu24-19365, 2024.

On-site presentation
Mogens Thalmann, Sondra Klitzke, Aki Ruhl, and Andre Peters

Climate change leads to increased water scarcity in many regions worldwide and thus forces many farmers to irrigate with reclaimed water (RW). Yet, due to incomplete elimination of pollutants during the treatment process, pollutants contained in the RW (e.g. organic micropollutants) can be introduced to the soil and may possibly be further transferred to groundwater and/or into eatable plants. To better understand the associated risks, observations of transport and transformation of organic micropollutants in soils is mandatory.

Lysimeter experiments were conducted from June 2021 to November 2023. Four lysimeters  with 1 m² surface area and 1 m depth were filled with sandy soil obtained from an agricultural field (two undisturbed, two disturbed). They were equipped with 9 suction cups inserted every 10 cm. During the vegetation periods, lysimeters were irrigated with RW. Additionally, RW irrigation was done as simulated aquifer recharge during winter time. Regularly, soil pore water (extracted via suction cups) and drainage water were sampled and subsequently analyzed for concentrations of fifteen organic micropollutants.

In this contribution, we exemplary discuss the results for , as two candidates of very different transport behavior.

CBZ concentrations above the limit of quantification were found solely in the depth of 10 cm depth. These findings suggest, that CBZ is either strongly sorbed and/or microbially transformed within the first few centimeters of the soil. In general, these findings are rather contradictive to findings in literature describing CBZ as a mobile substance (e.g. Ternes et al. 2007, Paz et al. 2016).

DZA showed very mobile behavior in the lysimeter in contrast to CBZ and percolated through the start (after 130 – 150 L of percolating water, depending on the lysimeter). In summer, DZA concentrations were significantly higher than those of the inflow, which we attribute to high evaporation and root water uptake combined with no DZA uptake by the plant roots. In autumn and winter, the seepage rates increased and DZA was transported towards the lower boundary.

Results of this study show that the organic micropollutants contained in typical RW may show very different transport behavior. While for some substances enhanced contamination of groundwater might be possible, others might be greatly retarded or even decayed. 



Paz, Anat, Galit Tadmor, Tomer Malchi, Jens Blotevogel, Thomas Borch, Tamara Polubesova, and Benny Chefetz. 2016. “Fate of Carbamazepine, Its Metabolites, and Lamotrigine in Soils Irrigated with Reclaimed Wastewater: Sorption, Leaching and Plant Uptake.” Chemosphere 160 (October): 22–29. https://doi.org/10.1016/j.chemosphere.2016.06.048.

Ternes, Thomas A., Matthias Bonerz, Nadine Herrmann, Bernhard Teiser, and Henrik Rasmus Andersen. 2007. “Irrigation of Treated Wastewater in Braunschweig, Germany: An Option to Remove Pharmaceuticals and Musk Fragrances.” Chemosphere 66 (5): 894–904. https://doi.org/10.1016/j.chemosphere.2006.06.035.


How to cite: Thalmann, M., Klitzke, S., Ruhl, A., and Peters, A.: Transport behavior of organic micropollutants in sandy soils – a lysimeter study , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10405, https://doi.org/10.5194/egusphere-egu24-10405, 2024.

Virtual presentation
Heta Ulmanen, Harri Turtiainen, Seija Kultti, Niina Kuosmanen, and Marie-Amélie Pétré

Per- and polyfluoroalkyl substances (PFAS) are persistent environmental contaminants linked to multiple adverse impacts and they are ubiquitous in the Finnish aquatic environment. The Vantaa River watershed is densely populated and constitutes a reserve water source for water supply in the Helsinki Metropolitan area (1 million people).  The aim of this research was to quantify PFAS concentrations and test a load estimator software (LOADEST) to determine loads at the mouth of Vantaa River before it flows into the Baltic Sea. Weekly water sampling was conducted near a continuous gauging station (Oulunkylä station) between March 2023 and October 2023 resulting in 28 samples. Water samples were analyzed for 50 PFAS in a commercial laboratory in Finland. Instantaneous daily load (riverine export) of individual and total PFAS (g/day) were calculated from the measured PFAS concentration in the river and daily river discharge data. The USGS application LOADEST was used to calculate individual and total PFAS loads at a daily interval over the monitoring period.

Σ50 PFAS concentration averaged 25 ng/L (range was 7-53 ng/L) and Σ50 PFAS load averaged 27 g/day (range was 6-121 g/day). Six PFAS constituted 83,4% of total quantified PFAS, perfluorooctane sulphonic acid (PFOS) and perfluoropentane acid (PFPeA) accounted for 40%. The total Σ50PFAS load at Oulunkylä was 4,7 kg over the entire monitoring period (197 days). In addition, the PFAS yield (kg/km2 yr) calculated by dividing the annual PFAS load by the drainage area was 5.15 10-3 kg/km2 yr in Vantaa River. Statistical measures of model performance indicated that LOADEST models for Σ50PFAS was within acceptable limits, with a Load Bias of –0.5% and a Nash-Sutcliffe Efficiency Index of 0.9. Further monitoring and modeling are warranted as this study shows that LOADEST can successfully be applied to the Vantaa River watershed, and it could be used to track the PFAS load reaching the Baltic Sea and follow the evolution of the system after restriction or ban of individual PFAS in Europe.

How to cite: Ulmanen, H., Turtiainen, H., Kultti, S., Kuosmanen, N., and Pétré, M.-A.: Occurrence and load modeling of per- and polyfluoroalkyl substances in an urban watershed Vantaa River, southern Finland, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6205, https://doi.org/10.5194/egusphere-egu24-6205, 2024.

Coffee break
Chairpersons: Yakov Pachepsky, Felicia Linke, Fulvio Boano
Virtual presentation
Zulin Zhang, Tianyi Li, and Yulin Chen

This study investigated the pollution of per- and polyfluoroalkyl substances (PFASs)  in sediments from the main stream of the Yangtze River, the world's third-longest river. Totally, 13 of 15 PFASs were detected in the sediments and the total concentrations ranged from 0.058 ng/g to 0.89 ng/g dry weight (dw), with dominant contaminants by perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). Concentrations of PFASs in the downstream were higher than those of upstream and midstream. Four main sources were analysed using the Unmix model, textile treatments and food packaging dominantly accounted for approximately half of the total sources, followed by metal electroplating (26.8%), fluoropolymer products (16.3%) and fluororesin coatings (7.4%). Total organic carbon (TOC), total nitrogen (TN) and grain size had significant correlation with the concentration of PFASs in sediments, indicating that the physical and chemical parameters could directly affect the adsorption process of PFASs. In addition, anthropogenic factors such as urbanization rate and per capita GDP also had a direct impact on the distribution of PFASs. Environmental risk assessment showed that PFOS posed medium to low risks to the Yangtze River, which might require further action to reduce their pollution level in the environment.

How to cite: Zhang, Z., Li, T., and Chen, Y.: Source apportionment and risk assessment of perfluorinated compounds in the world's third-longest river, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-12904, https://doi.org/10.5194/egusphere-egu24-12904, 2024.

On-site presentation
Liam Kelleher, Alice Phillips, Uwe Schneidewind, Telly Mobido, Lee Haverson, Evans Asamane, Cheick Sidibe, Youssouf Diarra, Ousmane Koilta, Semira Manaseki-Holland, and Stefan Krause

Drinking water (DW) is a necessity for life, and its pollution is of global concern for public health. Whilst the global occurrence of microplastic (MP) pollution in various environmental matrices is a focal point for research, the focus on microplastics in drinking water sources is somewhat less. Previous research has shown orders of magnitude difference in MP contamination of drinking water in residential areas, owing to local water source, water contamination, and container material.

Here we explore the exposure of residents living in rural and urban areas of Mali in Africa to microplastics in drinking water from varying sources. DW samples were taken from 83 homes, from urban residents in the city of Bamako and those in several rural settlements to the east of Bamako. These homes received their drinking water from traditional open wells, boreholes (narrower and deeper canals, often newer sources) and taps. Urban areas often had taps in each home, whereas rural areas had communal well and borehole water points.

A litre of DW was collected from each source which was subsequently sieved at 63 um and then washed with deionised water into a 20ml vial before shipping to the UK. Wet hydroxide digestion was carried out using 30% hydrogen peroxide at a minimum ratio of 1:1 sample to peroxide. After 24 hours the sample was filtered, and 80% of samples were mixed for 1 hour with Nile red, concentration 5 ug/ml, followed by filtering on glass fibre disk. These samples were assessed with fluorescence microscopy to assess polymer number and morphology. The remaining 20% were directly filtered onto Anodisc and assessed for polymer number and type using confocal Raman spectroscopy.

Our results capture a range of polymer types, morphological properties, and concentrations in the studied water samples. A statistically significant mean value of 9.9 mp/l (range 1-34 mp/l) for urban DW compared to 6.5 mp/l (range 0-15 mp/l) for rural DW was found. A range in distribution of MP concentration was found across the study sites regardless of geographic assignment. Morphologically fibres were most identified, 69% for rural and 72% for urban. The primary polymer types found were PMMA, PE, PS, PA/nylon, and PET.

The study sets the basis for a wider investigation of water sources in the region, followed by the perspective linking of health outcomes to the MP exposures found.

How to cite: Kelleher, L., Phillips, A., Schneidewind, U., Mobido, T., Haverson, L., Asamane, E., Sidibe, C., Diarra, Y., Koilta, O., Manaseki-Holland, S., and Krause, S.: Drinking plastic: a study of microplastic concentrations in drinking water from rural and urban sources in Mali, Africa, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11802, https://doi.org/10.5194/egusphere-egu24-11802, 2024.

On-site presentation
Jasper Griffioen

Contamination of surface water with pesticides is a well-recognised, notorious problem for decades. The Drentsche Aa river in the northern Netherlands is used as drinking water resource for the city of Groningen and its surroundings. Its quality is thus relevant with respect to both ecological and human water quality. Pesticide pollution in the Drentsche Aa catchment has been recognised for years. Environmental management programs have been implemented that aim to improve the water quality and in which a broad group of stakeholders has been involved. Last year, a committee evaluated the current status and suggested measures to improve the water quality. The waterboard ‘’Hunze en Aa’s’’ helpfully provided the data for the evaluation.

Water quality with respect to pesticides has been intensively studied for the period 2011-2022 (except 2014). The monitoring changed somewhat in the course of time but is summarised as follows. Time proportional sampling of river water was done on a weekly basis at different locations in the catchment and up to 141 pesticides and metabolites get analysed. Targeted grab sampling campaigns were additionally performed. 

Non-compliance at the inlet for drinking water production was most frequently observed for MCPA followed by dimethenamid, MCPP and metamitron and to a lesser degree 13 other pesticides. MCPA and MCPP are widely used. Dimethenamid and metamitron are used for flower bulbs, the former also for field vegetables and the latter for sugar beets. In the catchment, non-compliance to the drinking water standard is typically observed during May-August for the pesticides. Metabolites were observed year-round but do not show non-compliance.

Targeted grab sampling shows that pesticides reach surface water during heavy rain storms in the summer by surface runoff and drainflow. This is a well recognised leaching mechanism for pesticides from agricultural fields. However, pesticides also became detected in river water in weeks with little or no rain. This may be attributed to drift despite mitigating measures to reduce drift to surface water. There is also evidence that irrigation of drained parcels leads to surface runoff and drainflow of pesticides to surface water. The erratic occurrence of several pesticides is thus explained by a combination of reasons: 1. heterogeneous application of pesticides in space and time, 2. non-uniform leaching partly due to surface runoff that shows catastrophic event behaviour and 3. limited success of the implementation of measures being implemented on a voluntarily basis and not to the full extent. The data also show that pesticides not only originate from agricultural activities but also from urbanised areas. Here, pesticides were found that were forbidden for non-agricultural purposes at the time of observation.

The monitoring results show an erratic spatio-temporal pattern and no trend-based improvement as required by the EU Water Framework Directive. The voluntarily measures are thus not sufficiently effective. Climate change with more frequent heavy rain storms and greater need for irrigation may worsen the situation. Thus, more stringent measures are required which implementation may be forced by new legislation under the Environmental Law that came into force at 1 January 2024.

How to cite: Griffioen, J.: The erratic problem of pesticide pollution of the Drentsche Aa river as resource for drinking water, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-8217, https://doi.org/10.5194/egusphere-egu24-8217, 2024.

On-site presentation
Jaime Dueñas-Moreno, Abrahan Mora, and Jürgen Mahlknecht

The Atoyac River Basin is the largest riverine-reservoir system in Central Mexico. Along its course, the Atoyac River is joined with the Zahuapan River (major tributary) and receives several inputs of untreated or poorly treated urban and industrial wastewaters before flowing to the Valsequillo reservoir in the lower basin. In addition, its contamination is a cause of concern, given the presence of several hospitals and health centers along the main watercourse in Puebla and Tlaxcala States. Water from the Atoyac River Basin serves as a source for irrigation in surrounding areas. Therefore, this study aimed to evaluate the occurrence and ecological risk of five contrast agents—amidotrizoate, iomeprol, iopamidol, iopromide, and gadolinium—through the Atoyac River Basin. For this purpose, a total of 29 surface water samples from this system were collected and analyzed by HPLC coupled to tandem mass spectrometry and ICP-MS (in the case of Gd) in April 2022.

Among the contrast agents, amidotrizoate was not detected in any of the water samples, and iomeprol was only found in the Zahuapan River, with concentrations ranging from 0.023 to 0.091 µg L-1. In addition, iopamidol and iopramide were detected in the Zahuapan River (up to 0.2 and 0.86 µg L-1), Atoyac River before the Zahuapan-Atoyac confluence (up to 0.15 and 0.21 µg L-1), Atoyac River after Zahuapan-Atoyac confluence (up to 1.3 and 3.7 µg L-1), and Valsequillo Reservoir (0.39 and 0.49 µg L-1). Although the Valsequillo Reservoir acts as an oxidation lagoon, both compounds were found in the dam curtain with concentrations between 0.2 and 0.35 µg L-1, respectively. These values were not far from their average concentration in nine water samples analyzed in this reservoir (0.26 and 0.41 µg L-1). Therefore, this demonstrates their recalcitrant nature, as well as their high persistence in the environment. On the other hand, anthropogenic gadolinium was only detected along the Atoyac River, with concentrations ranging between 9.97 × 10-3 and 0.35 µg L-1. The highest concentrations of most contrast agents were found in the urban area of Puebla, corresponding with the Atoyac River after the Zahuapan-Atoyac confluence.

The ecological risk assessment revealed that the analyzed aquatic organisms —fish, daphnids, and green algae— exposed to these contrast agents resulted below the safety limit. Although these contaminants are considered safe, it is important to highlight that this study does not consider temporal concentration changes; therefore, significant anomalous events related to wastewater discharges may occur. In addition, the presence of contrast agents in this basin is highly concerning because its waters are used for crop irrigation. Therefore, the accumulation of these contaminants in soils and plants may have negative impacts on the health of consumers, particularly causing nephropathies and heart diseases.

How to cite: Dueñas-Moreno, J., Mora, A., and Mahlknecht, J.: Occurrence and ecological risk assessment of contrast agents in a highly polluted riverine-reservoir system in Central Mexico, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13205, https://doi.org/10.5194/egusphere-egu24-13205, 2024.

On-site presentation
Reynold Chow, Emma Davies, Samuel Fuhrimann, and Christian Stamm

South Africa has one of the most productive and diverse agricultural economies in Africa. Consequentially, it is the leading pesticide user in Sub-Saharan Africa. The Western Cape is a dominant agricultural region in South Africa, making it particularly vulnerable to pesticide pollution. After application, pesticides can be transported to rivers, potentially causing adverse ecological and human health effects. Thus, there is an urgent need to understand the sources and risk of aquatic pesticide pollution.

To achieve this, we deployed passive samplers for two-week intervals every month from February 2022 - March 2023 in three rivers within agricultural catchments (Piketberg, Grabouw, and the Hex River Valley) in the Western Cape. A control sample was deployed in Jonkershoek Nature Reserve. A pesticide monitoring campaign from 2017-2019 in the same agricultural catchments identified year-round detections despite few agricultural applications, making sources and drivers of pesticide pollution unclear. Thus, in addition to 44 pesticides, 20 drugs were analysed using LC-MS/MS as an indicator for wastewater treatment plant effluent. 22 pesticides and seven drugs were detected above the limit of quantification.

While some pesticides showed elevated concentrations and detections during the main pesticide application period which indicates rainfall and application as a contamination driver, some pesticides without year-round agricultural applications (e.g., imidacloprid) had high detection frequencies and concentrations out of the main application season. However, such compounds typically had high Groundwater Ubiquity Scores. This suggests constant leaching of pesticides into groundwater connected to rivers as a possible contamination source.

Piketberg had high cumulative drug concentrations which correlated strongly with cumulative pesticide concentrations, whereas Grabouw and Hex River Valley did not. This holds particularly true for carbendazim and terbuthylazine. This suggests that some pesticides in Piketberg are likely sourced from both wastewater treatment plants and agriculture, whereas the absence of drugs in Grabouw and Hex River Valley suggests that pesticides are more likely sourced from agriculture. Herbicide detections in Jonkershoek Nature Reserve (e.g., atrazine) indicate contamination possibly sourced from atmospheric transport or invasive plant control and trail maintenance.

A risk evaluation using European Environmental Quality Standards revealed that four pesticides were detected at concentrations exceeding their respective threshold levels, namely imidacloprid, chlorpyrifos, terbuthylazine, and spiroxamine. The omnipresence of imidacloprid in all agricultural catchments and monitoring campaigns are cause for concern. This highlights the need for distinct monitoring approaches and the implementation of tailored mitigation measures. Future sampling of groundwater and wastewater influent and effluent in all study catchments is key to improve our understanding of pesticide transport pathways.

How to cite: Chow, R., Davies, E., Fuhrimann, S., and Stamm, C.: Drug analysis as a tracer of pesticide pollution from wastewater treatment plants in the Western Cape, South Africa, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18329, https://doi.org/10.5194/egusphere-egu24-18329, 2024.

Part 2
On-site presentation
Gijsbert Cirkel, Lucas Borst, Jamal El Majjoui, and Martin van der Schans

The western part of the Netherlands depends largely on river water from the Meuse and Rhine rivers for drinking water supply, which is infiltrated into Managed Aquifer Recharge (MAR) systems in the Dutch coastal dunes. Pre-treated river water is infiltrated through open basins and recovered after soil passage for further treatment. This soil passage is a crucial step in drinking water treatment where unwanted microorganisms are efficiently removed. Field studies by Schijven et al (1998,1999), among others, showed that log removal during saturated transport in these systems is more than sufficient to produce microbiologically safe drinking water. Nevertheless, in subsequent years, fecal indicator organisms were still found with some regularity in the abstracted water. It was suspected that this (re)contamination was caused by short circuit flow with feces-contaminated water from ground level through the unsaturated zone. Conducting several field experiments confirmed this hypothesis and provided unique insight into transport behavior and log removal in the unsaturated zone and the role of preferential flow under field conditions. Results of the field trials have been implemented in guidelines for design and management of MAR systems and whether to allow grazing livestock near the MAR-systems for nature management. In this contribution we present the results of a series of field trials, spanning 20 years, providing unique insight in removal of fecal indicator bacteria in unsaturated dune soils and increasing insight in processes responsible for recontamination of infiltrated river water. 

How to cite: Cirkel, G., Borst, L., El Majjoui, J., and van der Schans, M.: Fecal recontamination of infiltrated water in Dutch Managed Aquifer Research systems; 20 years of field research, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10453, https://doi.org/10.5194/egusphere-egu24-10453, 2024.

Virtual presentation
Shulamit Nussboim, Orah Felicia Rein Moshe, Elazar Volk, Jonathan B. Larrone, and Lea Wittenberg

Organic pollutants contain a variety of compounds that emerge from pest control as well as irrigation with treated effluents. Physico-chemical properties, as well as the history of application, determine distribution in flowpaths. Field-scale research, concentrated on common compounds or included many pesticides, yet analysis did not take the advantage of multiple behavior ranges of many compounds. Rarely short-term time series were collected for organopollutants.

In the current research subsurface and groundwater samples were collected from agricultural fields having subsurface drainage systems. Appling subsurface water in conditions of floods during winter required a demonstration of the subsurface unique composition, to avoid using samples including mixing with streamwater or groundwater. Samples were collected before, during, and after storm resulting in time series for subsurface and groundwater. No pest control intervention was taken thus results demonstrate authentic filed conditions. Analysis of time series in this study showed patterns indicating transport processes in the subsurface such as piston flow and leaching of stormwater, occurring in two stages of the storm. This result was supported as well in clustering analysis: clustering clearly showed different compositions of water samples taken in each stage. The clustering demonstrated as well differences between runoff, subsurface and, groundwater, as well as differences between adjacent fields.

How to cite: Nussboim, S., Rein Moshe, O. F., Volk, E., Larrone, J. B., and Wittenberg, L.: Organic pollutants leaching in agricultural field: patterns in groundwater and subsurface water, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14645, https://doi.org/10.5194/egusphere-egu24-14645, 2024.

On-site presentation
Astrid Harjung, Leo Chavanne, Bradley McGuire, Claudia Wenzel, and Yuliya Vystavna

The Danube at Vienna drains a catchment of ~100,000 km2 and is an alpine river with an average discharge of 1900 m3/s that can vary by orders of magnitude. Flood events commonly result from snowmelt during the spring and early summer, heavy rainfalls during late summer and autumn, and ice burst events during winter. The most important tributary is the Inn, draining a large portion of the Austrian Alps. This catchment consists of the northern Calcareous Alps, the Palaeozoic Greywacke zone, and the Crystalline zone; elevations range from 310 to 3800 m. The mean discharge of the Inn at the confluence is 750 m3/s. Downstream of the confluence, southern tributaries from high rainfall areas in the Calcareous Alps and northern tributaries from areas with less rainfall and granitic geology enter the Danube. The Danube catchment is not only geologically, topographically, and climatologically diverse, but also contains diverse land use: forests; intensive and extensive agriculture sites; industrial and urbanized centres. Along the Inn, agricultural activity is focused on the Inn valley. Flatter regions upstream of Vienna, are used for crops, horticulture, and intensive livestock farming. Nitrate concentrations in the groundwater of these areas is often near the Austrian drinking water limit of 50 mg/L. 

The International Commission for the Protection of the Danube carries out synoptic sampling campaigns every few years. Water stable isotopes trace water origin and mixing. Nitrogen and oxygen isotopes of nitrate together with compounds of emerging concern (CECs) can delineate pollution sources and biogeochemical cycling processes. Using these tools revealed that tributaries contributed nitrate from different sources and CECs, while the mainstem generally mixed and diluted these contributions. Snowmelt derived water fractions from the Inn catchment, controlled Danube water chemistry but also diluted pollutants and influenced nitrate processes. An international study on CECs documented high CEC cumulative concentrations in the Vienna Danube. These results, however, also included samples taken downstream from the Vienna Wastewater treatment plant.

None of these studies have investigated the temporal component, considering the highly variable flow regime of the upper Danube. Here we present the results of a monitoring program carried out in collaboration with a public high school located on the Vienna Danube. We took monthly field samples of the Danube together with the pupils and discussed the results. The hydrological year described here was exceptional from a historical point of view but might show how hydroclimatic circumstances could emerge in a global warming scenario: A very dry and warm winter in the Alps was reflected in isotope ratios and CEC concentrations from November-April. Variability in the isotopic ratios and CECs increased in May likely due to higher contributions from the Alps, as compared to local groundwater. A recorded flooding event in late summer showed completely different pattern with regards to CECs and isotopes. Some CECs were diluted, while previously not detected ones appeared. Besides the importance of monitoring to understand the impacts of an accelerated hydrological cycle on river, this study shows the fruitful integration of schools into environmental monitoring.

How to cite: Harjung, A., Chavanne, L., McGuire, B., Wenzel, C., and Vystavna, Y.: Hydrology shapes the Danube River pollution in Vienna, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15838, https://doi.org/10.5194/egusphere-egu24-15838, 2024.

On-site presentation
Dikshant Bodana, Abhishek N Srivastava, Rajendran Vinnarasi, and Sharad K Jain

Rivers are susceptible to metal pollution arising from anthropogenic activities such as mining, industrial processes, and urban runoff. Metals from both natural and man-made sources enter the river system and either settle in the riverbed sediments or are distributed in the aqueous, floating matter. Under some environmental conditions, the accumulation of metals in river systems disrupts biological processes. Apart from metal pollution, the escalating concentrations of nutrients, specifically nitrogen and phosphorus into aquatic ecosystems are of growing concern. The excess concentartions of metals and nutrients pose severe environmental challenges such as lake eutrophication and groundwater pollution. Therefore, the sustainable solution to mitigate their adverse environmental effects is need of the hour.

Phytoremediation is a green remediation technology that employs plants to remove, detoxify, or immobilize toxins from soil, water, or air. The plants and their related microbial populations improve water quality by absorbing, adsorbing, and transforming contaminants like metals, nutrients, etc. In this research, a pot study was performed to investigate the efficacy of phytoremediation. In the controlled environment, small-scale tests were undertaken to examine the growth, pollutant removal capabilities, and effectiveness of using specific plants for larger-scale applications. The target pollutants were heavy metals (As, Al, Ca, Cd, Co, Cu, Fe, Pb, Mg, Hg, and Ni), macro-nutrients (Na, K, and Ca), and micro-nutrients (nitrates, ammonia nitrogen, and phosphates). Experimental setup included polyvinyl chloride containers (5 L capacity) as the vessel (pot) for growing Canna Indica plants. Water sample from Ratanpuri in Hindon river, one of the highly polluted rivers in north India, was used for the treatment. Initially, the containers were filled with 2.5 L of growing medium (soil, sand and gravels), arranged in a block design, and the experiment was performed for ten days (two runs), depending upon their treatment efficiency. Initial and final characterizations of water samples were performed as per standard methods.

The phytoremediation efficiency of all considered metal parameters through Canna Indica was observed in the range of 52-60 % which prospectively got absorbed via phytoextraction. Moreover, the efficacy of nutrient removal, was also obtained satisfactorily ranging from 60-78%. Considering removal efficiencies, phytoremediation using Canna Indica could be economically and environmentally sustainable for countering nutrient and metal pollution at field scale, provided its controlled monitoring is performed effectively. Pot-scale study results could be baseline that support usage of Canna Indica at field scale in wetland systems for detoxifying ecosystems and assuring soil and water quality restoration in the face of increasing anthropogenic demands.

How to cite: Bodana, D., N Srivastava, A., Vinnarasi, R., and K Jain, S.: Green Remediation: Canna Indica for Sustainable Detoxification of Metals and Excess Nutrients, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11102, https://doi.org/10.5194/egusphere-egu24-11102, 2024.

On-site presentation
Miriam Glendell, Lydia Niemi, Zisis Gagkas, Mark Taggart, Stuart Gibb, Naoko Arakawa, Claire Anderson, and Sharon Pfleger

Pharmaceutical pollution is a globally recognised public health and environmental issue that can negatively affect aquatic organisms, impact on drinking water quality and contribute to the spread of antimicrobial resistance. In this research, we developed the first UK multi-criteria decision support tool (DST) for medical practitioners to encourage eco-directed prescribing that considers environmental risk factors alongside medical considerations. The probabilistic DST, based on Bayesian networks, implemented a novel decision-making framework as a blueprint to predict environmental risk and inform eco-directed prescribing for an initial list of priority pharmaceuticals. The risk criteria agreed with stakeholders from both healthcare and environmental sectors included pharmaceutical physico-chemical properties; prescription and excretion rates; sewage treatment removal rates and dilution in the freshwater environment.

The priority compounds were selected through surveys, facilitated discussion and voting by stakeholders across the environment, medicines regulation, prescribing, public health and pharmaceutical industry sectors. Based on clinical and environmental factors, four pharmaceuticals were selected: carbamazepine, clarithromycin, fluoxetine, and propranolol. Expert consultation and literature review identified data on the environmental exposure and hazard of selected pharmaceuticals. Data was collated into a database, following a classification system based on prescribing data (population standardised, by mass), ecotoxicological data, environmental monitoring data, and drug physicochemical properties. Scotland-wide risk simulation models were developed, with mapping to visualise risk levels in freshwater catchments. The models show a gradient of risk in Scotland’s freshwaters, with greatest risk in the most highly populated areas.

The project has helped to increase awareness on environmental impact of pharmaceuticals, and has progressed cross-sector activity to develop support tools to introduce environmental data into prescribing decision-making in Scotland.

How to cite: Glendell, M., Niemi, L., Gagkas, Z., Taggart, M., Gibb, S., Arakawa, N., Anderson, C., and Pfleger, S.: Environmental risk modelling of pharmaceuticals in the water environment: towards eco-directed prescribing in Scotland, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-3577, https://doi.org/10.5194/egusphere-egu24-3577, 2024.

Posters on site: Mon, 15 Apr, 10:45–12:30 | Hall A

Display time: Mon, 15 Apr 08:30–Mon, 15 Apr 12:30
Chairpersons: Matthias Gassmann, Julia Derx, Yakov Pachepsky
Carmen Sáez Camacho, Arianna Bautista, Olha Nikolenko, Laura Scheiber, Marinella Farré, Anna Jurado, and Estanislao Pujades

Due to the increasing demand of water, urban aquifers are an alternative source of water supply. However, they are at risk of contamination from persistent and mobile organic compounds (PMOCs), especially per- and polyfluoroalkyl substances (PFASs), which are artificial organic substances widely used across various industrial sectors. PFASs are considered toxic, mobile and persistent, and have therefore gained significant attention in environmental chemistry. Moreover, PFASs precursors transform into more recalcitrant and mobile products under natural conditions. Therefore, it is needed to investigate the fate of PFASs when they reach aquifers to use groundwater safely. However, there is limited information about the processes which affect their behaviour in groundwater, especially at the field-scale. In this context, the aim of this investigation is to assess and identify processes that control the evolution of PFASs in an urban aquifer in Barcelona, where groundwater behaves analogously to a river bank filtration system. A part from PFASs, 4 PMOCs were also analysed. During a summer campaign, 21 groundwater and 6 river samples were collected revealing the presence of 17 PFASs products, 3 novel PFASs and 4 PMOCs non-PFASs. PFASs products were found to be ubiquitous, with the highest concentrations found in PFBS, TFA and TFSA. Non-PFASs and novel PFASs, with the exception of Sulfanilic acid, were found to be present in very low concentrations. It was observed that the redox conditions influence the behaviour of a number of PFASs controlling their attenuation capacity or recalcitrant behaviour. Most substances showed accumulation, possibly explained by sorption/desorption processes or by transformation processes, highlighting the challenges associated with PFASs remediation. In addition, the PFAS TFSA and two of the longest chain PFASs detected presented removals at different intensities. Our results will have tremendous implications for establishing the evolution of PFASs along the groundwater flow and might be extended to similar research areas such as Manage Aquifer Recharge techniques.

How to cite: Sáez Camacho, C., Bautista, A., Nikolenko, O., Scheiber, L., Farré, M., Jurado, A., and Pujades, E.: Occurrence and fate of perfluoroalkyl and polyfluoroalkyl substances (PFASs) in an urban aquifer located at the Besòs River Delta (Spain), EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-658, https://doi.org/10.5194/egusphere-egu24-658, 2024.

Shafkat Sharif, Jan Willem Foppen, and Marc Teixidó Planes

Tire wear rubber particles (TWRP) fall under the umbrella of microplastics and are responsible for synthetic particulate pollution in the urban environment. Urban stormwater runoff carries these particles towards receiving water bodies (e.g., aquifers, rivers, or sea). In particular, studies on their migration behaviour to the subsurface through stormwater infrastructures are still elusive.

The current study investigated the vertical migration of end-of-life truck and track tire rubber particles (TPs) in synthetic stormwater (SSW) with 5 mg C/l dissolved organic carbon through laboratory-based infiltration sand columns. Thereto, 200 mg of the particles, with a size range of 63 – 180 µm, were placed inside the column at a depth of 3 cm. Subsequently, 6 litres of SSW were flushed intermittently through the columns in varying wetting, drying, and saturation cycles simulating heavy precipitation patterns. Effluents were collected after each cycle and retained particles within the column were extracted at specific depth intervals to test for Zn concentration (as ZnO is a commonly used additive agent in tire manufacturing) as a proxy for tire particles. We found that 45 – 95% of the truck and track TPs were retained in the seeded depth of 0 – 3 cm varying with different scenarios. Significant migration occurred in the first depth interval layer (3 – 8 cm) of the columns, whereas the other layers received fewer and nearly uniform amounts of TPs. The truck particles showed 24% more penetration for wetting and drying cycles, whereas upon reduction of gap time between two subsequent wetting cycles track TPs penetrated 18% more. Furthermore, longer saturation (24-hour contact time with SSW between cycles) consistently released 2 – 6 times more Zn than shorter duration times. Our results indicated that large rubber particles in the size ranges we studied remain in the topmost part of the soil. In case of moist or wet soils, these particles will act as a source of pollution, which will finally leach into groundwater, thereby polluting aquifers.

How to cite: Sharif, S., Foppen, J. W., and Planes, M. T.: Migration of tire rubber crumbs through variably saturated laboratory-scale sand columns, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-761, https://doi.org/10.5194/egusphere-egu24-761, 2024.

Eva Weidemann, Johanna Dülfer, Katrin Matthes, and Matthias Gassmann

Nitrification inhibitors and urease inhibitors are organic chemicals that have been used in agriculture for decades to slow down nitrification in order to keep plant-available ammonium in the soil for longer and to reduce the leaching of nitrate. Furthermore, they serve to reduce the rapid conversion of urea to ammonia, which also has a positive effect on climate protection. Being applied to agricultural fields, there is a high risk that these substances are contaminating water bodies. We therefore initiated both an environmental sampling campaign and a lab study of the environmental fate characteristics of selected nitrification inhibitors and urease inhibitors.

In our first study, we took samples in Northern Hesse and the area of Goettingen (Germany) from streams, lakes and groundwater between October and December, mainly in agricultural areas. The samples were then analysed for six different nitrification and urease inhibitors (1) 3,4-dimethylpyrazole phosphate (DMPP), (2) 4-amino-1,2,4-triazole (ATC), (3) Dicyandiamide (DCD), (4) N-(2-nitrophenyl)phosphoric triamide (2-NPT), (5) Mixture of N-((5-methyl-1H-pyrazol-1-yl)methyl)acetamide and N-((3-methyl-1H-pyrazol-1-yl)methyl)acetamide (MPA) and (6) H-1,2,4-Triazol. We found solely two of the inhibitors in the samples, DCD and H-1,2,4-Triazol, which corresponds to the results of a study from 2014 published by the DVGW.

In a second study, we wanted to examine under what circumstances and with what dynamics the inhibitors are transferred to deeper soil zones and what influence they have on the leaching of nitrate at different temperatures and in different soils. For this purpose, we chose the above mentioned five nitrification or urease inhibitors (1-5), which are currently used in agricultural fertilizers in Germany. In order to obtain information about their behavior in the environment, we have planned a study to investigate their leaching and transformation behavior in the unsaturated soil zone. For this purpose, agricultural topsoils were selected and filled into 25 cm high columns with a diameter of 7 cm. Three fertilizers containing the above-mentioned compounds were applied separately to the soil columns at an application rate of 150 kg N/ha. Each of the variants was tested in triplicate in two different temperature ranges (12 °C, 20 °C). Irrigation was carried out over 12 weeks with a groundwater recharge rate of the fall/winter period. The leachate was analyzed 1-2 times a week and at the end of the study the soil was analyzed at two different depths for the inhibitors as well as nitrate and nitrite.

How to cite: Weidemann, E., Dülfer, J., Matthes, K., and Gassmann, M.: Nitrification inhibitors in the soil-groundwater-river continuum of Germany, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-2088, https://doi.org/10.5194/egusphere-egu24-2088, 2024.

Xiaorong Li, Peter Robins, Jessica Kevill, Shelagh Malham, and Davey Jones

Treated and untreated wastewater enters estuaries via point source discharges, after which complex estuarine hydrodynamics can retain high concentrations of pathogens in these systems for days to weeks, posing a serious risk to public health. Through comprehensive fine scale three-dimensional numerical modelling, this research aims to study drivers of pathogen dispersal in estuaries and pathways of pathogen distribution. An interdisciplinary approach, combining knowledge from numerical modelling with laboratory derived data on pathogen behaviour and interactions with sediments, has been taken to improve the reliability of the model: 1) key fine-scale estuarine processes, i.e. current (including density current), turbulent mixing, and sediment transport have been studied using a process-based numerical model; 2) decay curves of target pathogens obtained through laboratory experiments for different water temperature, salinity, UV radiation have been implemented in the model; 3) the model also aims to incorporate pathogen attachment to sediments, their deposition, resuspension and subsequently altered decay rates.

The Conwy estuary in North Wales, UK, has been used as our case study. The estuary holds considerable historical and contemporary significance in terms of shellfishery and tourism. With a catchment area of 678 km2 supporting a population of ~80,000 and large pastures, the estuary is susceptible to a range of pathogens, posing a public health risk via ingestion of bathing waters and indirectly via sea food.  The transport of pathogens from point sources, including wastewater discharge and sewage overflow, into the coastal environment has been studied under both current and future climate conditions such as sea level rise, warmer coastal waters, stronger river flow and population growth drawn from climate projections. As a further aspect of this research, conceptual estuarine systems will also be used to study fate and transport of pathogens under common estuarine dynamics and under representative climate scenarios.  This integration will allow for a more holistic approach that widens the applicability of the findings.

This research will provide improved understanding of pathogen dispersal in coastal waters and the impact of climate change on pathogen distribution and potential exposure to humans. It will also provide insights for the development of adaptation strategies to protect public health under changing environmental conditions.

How to cite: Li, X., Robins, P., Kevill, J., Malham, S., and Jones, D.: Modelling pathogen dispersal and distribution in estuarine systems under changing environment, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-2535, https://doi.org/10.5194/egusphere-egu24-2535, 2024.

Christiane Meier, Korinna Ziegler, Lukas Kopp, Frank Sacher, and Stephan Fuchs

Numerous chemicals enter surface waters via various emission pathways. One important group of those are biocides, which are used in a broad range of products, e.g. as disinfectants, agents against insects, for rodent control, or as material preservatives. Biocides are primarily used in urban areas, collected and transported in sewer systems either to sewage treatment plants (STP) or directly to the receiving water body (stormwater outfalls). During heavy rainfall events, however, sewage treatment plants cannot completely treat the increased sewage volume. Therefore, a part of the untreated sewage water, that contains also biocides, enters the surface waters as combined sewer overflow (CSO).

To assess the importance of different urban emission pathways of biocides, a study was conducted in Germany in the exemplary catchment of the river Alb flowing through the city of Karlsruhe. Water quality decreases by passing the city area from a good status to a bad status as defined in the Water Framework Directive (WFD). It is questioned if and which urban entry pathway contributes to which extent to the increasing pollution of the river Alb. Between 03/2021 and 12/2023 in total 130 samples were taken from the river Alb, the effluent of the municipal STP, combined sewer overflow and storm water outfalls and subsequently analysed for 42 biocidal substances, mainly disinfectants, material preservatives and pest control products. 26 out of 42 substances were detected: 13 in the river water while 26 substances were detectable in the urban emission pathways. These substances are mainly used as material preservatives, e.g. carbendazim, diuron, isoproturon and terbutryn, and were detected in approximately 90 % of all samples. For some substances the environmental quality standard (EQS) or the predicted no effect concentration (PNEC) are exceeded. For example, in CSO-samples the concentration of the insecticide permethrin exceeds 6 to 12-fold the PNEC for surface water. Even in consideration of a regulatory dilution factor of 10 for the discharge into surface waters, the PNEC is exceeded. This can be seen as an indication that pyrethroids used in urban areas are mainly transported into surface waters via CSOs, where they pose a risk to aquatic organisms. Due to low environmental concentrations and associated challenging analytical methods, other pyrethroids were not or only seldom detected.

Present results show that biocidal substances used in material preservation products are (continuously) released via numerous pathways into surface waters, and combined sewer overflows are important emission sources of biocides in the aquatic environment. However, the findings of a part of the substances investigated cannot be unambiguously attributed to a biocidal application, since the same substances can be used as, for example, human or veterinary pharmaceuticals. Nevertheless, the project provided important insights into the occurrence of biocides in urban runoff components and identified combined sewer overflows as a relevant emission pathway in urban areas which needs further to be investigated.

How to cite: Meier, C., Ziegler, K., Kopp, L., Sacher, F., and Fuchs, S.: Release of biocides in an exemplary urban river in Germany, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-5835, https://doi.org/10.5194/egusphere-egu24-5835, 2024.

Margherita Vendruscolo, Carlo Vincenzo Camporeale, and Luca Ridolfi

Braided rivers were deeply investigated as regards their morphodynamical evolution, conversely less interest was shown for the role that their peculiar topology can play in other phenomena, such as transport processes.

Our work deals with the link between the river network structure and the downstream transport of scalars, for example chemical substances (nutrient or pollutant) or suspended sediments. The river network acts as a mixer on the injected substance, thus causing a dispersion effect on the transport process. This phenomenon - known as geomorphological dispersion in the river networks at basin scale - becomes particularly relevant in braided rivers due to the complexity of their networks and their possible crucial impact on fluvial water quality.

Adopting the approach of GIUH theory, we develop a mathematical model for the dispersion in braided rivers. In particular, we assume to inject a given initial distributions of the scalar in the network inlets and aim to compute the outlet discharge by only considering the network properties, i.e. discharges at bifurcations, branches travel times, and network topology.

What we observe from the results is a strong dominance of the network topology over branch-specific hydraulic properties with regard to the outlet distributions, meaning that the properties at the network scale seem to have more influence than those relative to the scale of the individual branch. Moreover, we show how the outlet distributions depend on network properties. We find that, as the network grows, temporal distributions become closer and closer to Gaussians.  This behaviour - expected in light of the central limit theorem - is caused by the succession of bifurcations and reconnections interspersed with branches having different travel times.

How to cite: Vendruscolo, M., Camporeale, C. V., and Ridolfi, L.: Dispersion induced by braided river morphology, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-7656, https://doi.org/10.5194/egusphere-egu24-7656, 2024.

Rallis Lougkovois, Konstantinos Parinos, Georgios Gkotsis, Maria-Christina Nika, Nikolaos Thomaidis, Alexandra Pavlidou, and Ioannis Hatzianestis

Comprehensive monitoring of priority pollutants and emerging contaminants is considered necessary to provide insights concerning the quality of ecosystems. Chemicals such as plant protection products, pharmaceuticals, illicit drugs, personal care products, as well as per- and polyfluoroalkyl substances (PFAS) often end up in the environment and are distributed in different compartments. Human related activities and sewage facilities’ inability to remove them from the wastewater stream seem to be the main sources of contamination of the marine ecosystem. Upon ending up in the natural environment, both biotic and abiotic processes, such as hydrolysis and photolysis, take place, producing transformation products (TPs), suspected to be the cause of even more potent effects compared to parent compounds.

The region of Thessaly, Greece, was severely struck by sequential major storm events named “Daniel” and “Elias”, during the fall of 2023. Approximately 1.5 million tons of water per square kilometer rained down the surrounding area of Pagasitikos Gulf (Aegean Sea, Eastern Mediterranean) each day the phenomena were in effect. Naturally induced environmental change such as these may increase the number of chemicals, which end up in the marine ecosystem and relate to anthropogenic activities, often causing unpredictable damage to indigenous fauna and flora. Many of these compounds reach humans through the food chain and are classified as persistent, bioaccumulative and toxic (PBT).

Aiming to extract as many contaminants as possible from the studied samples, generic sample preparation protocols were applied using multilayer mixed-mode SPE cartridges to enrich the final extracts with thousands of LC-amenable, non-volatile, thermal unstable, semi-polar to polar, organic micropollutants.

The analytes were chromatographically separated using Reversed Phase Liquid Chromatography (RPLC). The chromatographic system was linked to a hybrid Trapped Ion Mobility Spectrometer coupled to High Resolution Mass Spectrometer (TIMS-HRMS). The occurrence of more than 2,000 chemicals from different chemical classes was investigated in the acquired HRMS-data through wide-scope target analysis based on strict identification criteria. TIMS provides an additional dimension of separation, adding increased value of confidence to the identification criteria, minimizing false positive selection, further optimizing wide-scope target screening methodology via HRMS analysis.

Preliminary results indicate the presence of numerous plant protection products in seawater and sediment samples, associated with agricultural activities, such as Azoxystrobin and Atrazine along with their respective TPs: Azoxystrobin acid and 2-hydroxy-atrazine, desethyl-atrazine and desisopropyl-atrazine. Pharmaceutical compounds were also detected in some cases, especially in areas close to wastewater treatment plants, such as Carbamazepine, along with its’ metabolites: 10,11-epoxy-carbamazepine and 10-hydroxy-carbamazepine, findings that could be attributed to reported overflowing of nearby sewage treatment plants, during the flood events. The presence of PFAS is also confirmed, following the detection of compounds such as Perfluorooctanesulfonic acid (PFOS) and Perfluorooctanoic acid (PFOA), possibly linked to the destruction of industrial and port infrastructure.

This work was funded by the Ministry of Development & Investment, National Strategic Reference Framework (NSRF) - Operational Program: “OP Transport Infrastructure, Environment and Sustainable Development”, in the frame of the Monitoring program for the ecological quality of rivers, transitional and coastal waters according to WFD 2000/60/ΕΕ

How to cite: Lougkovois, R., Parinos, K., Gkotsis, G., Nika, M.-C., Thomaidis, N., Pavlidou, A., and Hatzianestis, I.: Monitoring the presence of priority pollutants and emerging contaminants at Pagasitikos Gulf, Greece, following “Daniel” and “Elias” storm events, utilizing the technique of LC-VIP-HESI-TIMS-HRMS, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-7985, https://doi.org/10.5194/egusphere-egu24-7985, 2024.

Yolanda Picó, Yolanda Soriano, and Vicente Andreu

The increasing worldwide release of anthropogenic chemicals compounds into the aquatic ecosystems has led serious contamination of freshwater resources.  This study investigated the chemical composition of the water and sediments of L'Albufera Natural Park, Valencia, Spain, an area heavily impacted by intensive agriculture, surrounded by an industrial belt, highly urbanized and historically polluted. The goal was to assess the different water sources and anthropogenic influence in this managed area using nontarget analysis (NTA) combined with high-resolution mass spectrometry (HRMS). Surface water and sediment samples were collected from 51 sites during two sampling events in the May/June 2019 and September/October 2019. These two periods were selected because the most relevant crop in the area are rice fields and these two periods coincides with the starting of the cultivation and the harvest. The HRMS data was processed using Compound Discoverer™ version 3.3, and the results were analyzed using Principal Component Analysis (PCA). Agricultural practices are one of the most important sources of contaminants (mostly pesticides) including at concentrations >100 ng L-1 acetamiprid, azoxystrobin, chlorfenvinfos, chlorpyrifos, difenoconazole, dimethoate, fluvalinate, imazalil, imidacloprid, omethoate, propazine, tebuconazole, terbumeton deethyl, terbuthylazine, thiabendazole and tricyclazole. Increased presence and intensity of organic contaminants along the waterway was observed, indicating significant anthropogenic influence in the area. The NTA and post-processing were evaluated for reproducibility, demonstrating robustness with a 71.2% average reproducibility for compounds detected the 2 sampling trips. A detection frequency of 80% was the set criterion for detected compounds suggested as tracers. To prioritize samples, hierarchical cluster analysis was employed, and potential tracers for each water source were determined. Additionally, urban-influenced contaminants such as insect repellents, pharmaceuticals, and non-agricultural herbicides were identified along the channels that transports treated wastewater to the Natural Park. This study highlights the impact of human activities on L’Albufera Natural Park and demonstrates the effectiveness of NTA in differentiating and tracking water sources. The results emphasize the importance of reproducibility in NTA and provide guidance on implementing monitoring strategies by prioritizing samples based on chemical compositions.

How to cite: Picó, Y., Soriano, Y., and Andreu, V.: Suspected and non-targeted analysis of environmental contaminants in water and sediments of L’Albufera Natural Park by liquid chromatography-high resolution mass spectrometry, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-10676, https://doi.org/10.5194/egusphere-egu24-10676, 2024.

Yakov Pachepsky, M. Dana Harriger, Christina Panko Graf, and Matthew Stocker

Water columns and bottom sediments in freshwater bodies are two interacting environmental compartments that exchange microorganisms during both high-flow events and periods of base flow. The objective of this work was to quantify the coupled dynamics of FIB populations in water columns and bottom sediment using the three years of weekly monitoring E. coli and enterococci at forested, agricultural, and suburban land use locations along the montane creek in Pennsylvania, USA. Sediment was sampled in triplicate from the surface 0-1.5 cm layer. For both E. coli and enterococci, two population characteristics were used: (a) logarithm of concentrations in MPN per unit of mass of water or sediment, (logCwater and logCsediment) and (b) areal density in MPN cm-2. The annual cycle of logCwater and logCsediment annual cycle mimicked the sine-like changes in air temperature with amplitudes of 3 to 3.5 orders of magnitude. For both organism groups, relationships between water and sediment populations were convex; slopes of linear regressions of logCwatervs. logCsediment varied from 0.756 to 0.918 and from 0.274 to 0.533 for E. coli and enterococci, respectively; the least of the nonlinearity was observed at the forested site. Weekly increments of the E. Coli logCsediments nonlinearly increased with the total precipitation over the week with the rate of about 0.012 per mm precipitation. In the absence of precipitation during the week E. coli logCsediment decreased with weekly rates of 0.205±0.040 and 0.089 ±0.065 over warm and cold periods respectively. The ratio of the areal densities of FIB populations in water and sediment was overall large at the agricultural and suburban sites compared with the forested site.  The ratio tended to increase as the water stage increased. The bulk of the E. coli and enterococci populations was in the water column at agricultural and suburban sites and in the sedimentsat low flows. 

How to cite: Pachepsky, Y., Harriger, M. D., Panko Graf, C., and Stocker, M.: Coupled dynamics of indicator bacteria populations in water columns and bottom sediments of a mountain creek, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11480, https://doi.org/10.5194/egusphere-egu24-11480, 2024.

Matthew Stocker, Jaclyn Smith, and Yakov Pachepsky

The microbial quality of irrigation water is a major worldwide health concern. Assessments of irrigation water quality are conducted via the measurement of the fecal indicator bacteria Escherichia coli. More recently, the levels of antibiotic resistant bacteria in irrigation water have been highlighted as an emerging concern as they may be spread from surface waters to crops and soils. Composite sampling has been recommended in cases when larger sample sets cannot be collected across a waterbody. However there have been no reports which have compared the results of composite sampling with the spatial means or medians of fecal and antibiotic resistant bacteria within irrigation waters. The objectives of this work were to evaluate the representativeness of composite samples for estimating the levels of fecal and antibiotic bacteria in several irrigation ponds. In August and September of 2022, water samples were collected from dense sampling grids within five irrigation ponds in Maryland and Georgia, USA. Concentrations of generic, tetracycline, and cefotaxime-resistant E. coli and total coliforms were enumerated in all samples. Three composite samples were created for each pond: a composite of the interior, bank, and full sample sets. In general, we found the distributions of generic and antibiotic resistant bacteria concentrations did not significantly differ between bank and interior samples. Concentrations of antibiotic resistant bacteria ranged substantially across all the waterbodies. On average, the composite samples fell between the 60th and 70th percentile of the concentration distributions. In only a 9 and 14.5 % of cases (n = 90) did the composite sample value significantly differ (p < 0.05) from the mean or median, respectively, of the entire sample sets. Results of this work indicate that composite sampling may accurately be used to estimate the spatial mean or median of generic and antibiotic resistant bacteria concentrations in irrigation waters. These results will be used to improve the estimation of fecal contamination of irrigation waters as well as the presence of antibiotic resistant bacteria. 

How to cite: Stocker, M., Smith, J., and Pachepsky, Y.: Assessment of composite sampling for determining the levels of fecal indicator and antibiotic resistant bacteria in irrigation water, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-12548, https://doi.org/10.5194/egusphere-egu24-12548, 2024.

Barbara Clasen, Tamiris Storck, Tadeu Tiecher, and Andressa Silveira

The Brazilian biomes degradation puts the quality and integrity of aquatic ecosystems at risk. The disorderly advancement of human activities such as industry, livestock and agriculture make water resources vulnerable to contamination. In this way, the use and occupation of land in the river catchment directly reflects the possible contaminants that may be detected in surface waters. The Uruguay River catchment comprises the Pampa and Atlantic Forest Biomes in southern Brazil, in addition to parts of Argentina and Uruguay. It is estimated that there is a small portion of vegetation remaining in relation to the initial vegetation cover in this catchment, with a high fragmentation degree, due to intense degradation. Therefore, the objective of this study is to evaluate the emerging contaminants presence in the Uruguay River and biomarkers in fish Astyanax sp. exposed to the mixture of these contaminants in situ. To this end, samples of water, sediment and fish were collected over a year in 5 locations distributed along the Uruguay River (around 300km). The occurrence of metals, pesticides, medicines for human and animal use and hormones in water samples was analyzed, and the presence of pesticides in sediments and fish muscles. The presence of 14 active pesticide ingredients was detected, the insecticide imidacloprid being the most common, 13 medicines, 1 female hormone and 7 metals in the water. The presence of 4 pesticides and 3 pesticides bioaccumulated in the fish muscles were detected in the sediments. The results obtained in this study are extremely important for evaluating the contamination of a river basin of international importance. With this, it is possible to determine the possible river contamination sources, and, thus, define or propose improvements in management and mitigation measures aimed at improving environmental quality.

How to cite: Clasen, B., Storck, T., Tiecher, T., and Silveira, A.: Biomonitoring of emerging contaminants in a river in southern Brazil, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13136, https://doi.org/10.5194/egusphere-egu24-13136, 2024.

Julie Lions, Anne Togola, Hans Groot, Martine Bakker, Eric D. van Hullebusch, Ulf Miehe, Veronika Zhiteneva, Valeria Dulio, Pierre Boucard, Julia Hartmann, Nicole Heine, Thomas Track, Alexander Sperlich, Matthias Zessner, Carme Bosch, Massimiliano Sgroi, Francesco Fatone, Sonia Jou Claus, and Stefan Colombano and the H2020 PROMISCES project partners

Resource scarcity has increased interest in the circular economy (CE) for environmental, economic, and social sustainability. The goal is to minimize waste generation and efficiently incorporate waste back into production processes without adversely impacting human health or the environment.

By recognising the importance of assessing the potential accumulation of chemicals and associated  risks within the CE, the Horizon 2020 project PROMISCES focuses specifically on the so-called "forever chemicals" such as per- and polyfluoroalkyl substances (PFAS) in five CE routes, including semi-closed water cycles for drinking water (DW), wastewater reuse in agriculture, nutrient recovery from sewage sludge, material recovery from dredged sediments, and groundwater and land remediation for safe reuse.

Based on the results from literature reviews, experiments and case studies, the project addresses the fate and transfer of PFAS across these CE routes. Despite the challenge of analysing PFAS in complex matrices such as sludge and wastewater, robust and sensitive methods have been developed and the following conclusions can be obtained:

Wastewater treatment provides a limited removal efficiency, especially when wastewater treatment plants receive large contributions from industrial wastewater streams. Advanced wastewater treatment technologies implemented for micro-pollutant removal are not fully effective for all PFAS. Additionally, degradation of precursors can result in increased PFAS concentrations in the effluent. Consequently, until new treatment solutions are implemented, PFAS hotspots may not be able to implement wastewater reuse (e.g. for irrigation).

Riverbank filtration, as a first DW treatment stage, demonstrates limited removal of PFAS. Accordingly, in the presence of an upstream emission source, DW providers may need to implement advanced water treatment technologies.

During wastewater and landfill leachate treatment, particularly long-chain PFAS may accumulate in sludge. Although low level of targeted PFAS compounds were quantified, the presence of precursors in sludge is suspected and may present a barrier to its agronomic valorization. To date, PFAS content in sewage sludge is not regulated and depending on the country, sludge may be spread on agricultural land, incinerated, or disposed in landfills. 

Valorisation of dredged sediment as secondary raw material has the advantage of limiting the cost of management and limiting the use of raw materials. Depending on the nature of the sediment (in particular organic matter content) and on the PFAS loads, different treatments result in different removal efficiencies. Moreover, treatments can result in the formation of new persistent PFAS from precursors. When initial loads are low, it seems possible to eliminate PFAS from the solid fraction. Nevertheless, the destruction of residual PFAS in the washing solution is necessary.

In situ and on-site treatments of water and soil are confronted with environmental realities. Even if treatment trains can help overcome the complexity of PFAS treatment, the process efficiency is highly dependent on the alkyl chain length and the functional groups. As for sediment, although various treatment techniques exist, such as PFAS immobilisation, these do not result in complete degradation or removal of PFAS. This stands in the way of achieving a CE, as only after full removal of PFAS, safe reuse of resources can be guaranteed.

How to cite: Lions, J., Togola, A., Groot, H., Bakker, M., van Hullebusch, E. D., Miehe, U., Zhiteneva, V., Dulio, V., Boucard, P., Hartmann, J., Heine, N., Track, T., Sperlich, A., Zessner, M., Bosch, C., Sgroi, M., Fatone, F., Jou Claus, S., and Colombano, S. and the H2020 PROMISCES project partners: Fate and behaviour of PFAS in natural resources: towards a safe circular economy, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-16438, https://doi.org/10.5194/egusphere-egu24-16438, 2024.

Prabhat Dwivedi and Brijesh Kumar Yadav

Persistent elevated levels of heavy metals in river water used for irrigation can accumulate in aquatic and terrestrial organisms, disrupting the food chain, altering species compositions, and leading to ecosystem instability. An integrated risk assessment is thus essential to comprehend the cumulative effects of ongoing contamination, offering insights into the severity of hazards associated with heavy metal containing river water. The present research aims to analyze the spatial and temporal variations in the hazard index (HI) and ecological risk index (ERI) based on surface water samples collected along the Kali River. Further, this study pinpoints major heavy metals posing heightened risks, aiming to identify hotspot zones within the river basin. Seasonal water quality monitoring revealed elevated concentrations of Cr, Mn, and Ni during the pre-monsoon. Conversely, in the post-monsoon period, Cr, Fe, Mn, Zn, Cd, and Pb exceeded the drinking water standards established by BIS 2012 across the entire stretch of the Kali River. The ERI findings indicated that during the post-monsoon season, none of the water samples fell into the low ecological risk, whereas about 80% of samples were classed as low ecological risk during the pre-monsoon season. The observed seasonal shift in the computed ecological risk is likely attributed to the wash-off effect and the discharge of agro-industrial waste during the post-monsoon period. Moreover, the values of the ecological risk are higher at the upstream water sampling locations compared to downstream, indicating the effect of the dilution caused by domestic sewage originating from economically developed districts in western Uttar Pradesh state. Similarly, the findings from HI associated with human health indicate that both adults and children face potential carcinogenic and non-carcinogenic risks at all water sampling locations during post-monsoon season. However, in pre-monsoon season, only 34% of water sampling sites reported non-carcinogenic risk. Finally, a correlation was established between predicted risk indices and the observed data encompassing human health, community feedback, and ecological survey results. The findings indicate a robust correlation of 76% among sampling locations along the Kali River, indicating elevated environmental vulnerability in the basin. This study highlights the degraded condition of the Kali River ecosystem, posing threats to both humans and ecology. This necessitates immediate action for effective mitigation strategies to safeguard public health, preserve ecosystems, ensure the safety of agricultural and aquatic resources, and adhere to regulations for sustainable water management in the basin.

How to cite: Dwivedi, P. and Yadav, B. K.: Assessment of Integrated Health and Ecological Risks linked with Heavy Metal Pollutants in the Agro-industrial basin of Kali River, India, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-16658, https://doi.org/10.5194/egusphere-egu24-16658, 2024.

Robert Hynes, Zina Alfahl, Louise O'Connor, Florence De Bock, Catherine Burgess, Paul D. Hynds, Jean O'Dwyer, and Liam P. Burke

Shiga toxin-producing Escherichia coli (STEC) are zoonotic agents causing human gastroenteritis, with symptoms ranging from asymptomatic/mild to bloody diarrhoea and in rare cases haemolytic uraemic syndrome (HUS) and death. STEC serogroups O157 and O26 are most commonly linked to infection. Waterborne transmission represents a key exposure route and occurs through contamination of drinking water sources with human or mammalian faeces. Ireland has consistently reported the highest STEC infection rates across the EU. This study sought to investigate STEC concentrations in surface water bodies and groundwater wells located in the Corrib catchment in western Ireland over the peak human infection periods.

From late May to early December 2023, 19 sites comprising river (n=5) and private groundwater wells (n=14) were sampled on a fortnightly basis in the Black River sub-catchment of the Corrib catchment. Colilert-18® and quantitative PCR were employed to monitor the presence of total coliforms, E. coli and STEC serogroups targets O157 (rfbE) and O26 (wzx). Measured physico-chemical parameters included pH, temperature, and dissolved oxygen content, in addition to river discharge and groundwater table. These were amalgamated with publicly available data, including groundwater vulnerability and rainfall data from Geological Survey Ireland (GSI) and Met Éireann, and continuous river level and discharge data from the Office of Public Works (OPW).

Overall, 265 samples were collected comprising 75 river samples and 190 groundwater samples. E. coli was detected in 178 samples (67%), including all 75 river samples and 103 (54%) of groundwater samples.

STEC was detected in 225 samples (85%) overall and in 119 (67%) of E. coli positive samples. A total of 168 samples (64%) tested positive for STEC O157, comprising 34 rivers (45%) and 134 groundwaters (71%). STEC O26 was detected in 56 samples overall (21%) and was more prevalent in rivers (n=22, 30%) than groundwater (n=34, 18%). Of 103 E. coli positive groundwaters, 86 were STEC positive, giving a STEC to generic E. coli detection ratio of 83.5%. STEC O157 was detected in 82 (80%) and STEC O26 was detected in 24 (23%) of E. coli positive groundwaters.

Rainfall peaked in July (224.1mm), leading to increases in river discharge (2.137 m3/s mean peaking at 6.058 m3/s in mid-July) and groundwater level (10.11m mean peaking at 9.77m two weeks after heavy rainfall). STEC O157 concentrations peaked in the river samples during August (80% positive, mean concentration of 1.3x106 copies), and later in groundwaters (64% positive, mean concentration of 3.1x105 copies) during September. STEC O26 concentrations peaked earlier in late July for river samples (10% positive samples, mean concentration of 3.58x105copies) and early July for groundwater (22% positive, mean concentration of 2.9x106 copies).

We describe the dynamics of STEC in surface and groundwaters of a catchment in western Ireland. The peaks for STEC serogroups O157 and O26 in groundwaters correlate with “traditional” human peaks of infection for these serogroups in Ireland and are preceded by peaks in surface water concentrations. Findings will be useful in designing strategies for source protection and risk management of drinking water supplies.

How to cite: Hynes, R., Alfahl, Z., O'Connor, L., De Bock, F., Burgess, C., Hynds, P. D., O'Dwyer, J., and Burke, L. P.: Longitudinal monitoring of Shiga toxin-producing Escherichia coli (STEC) concentrations in surface waters and groundwater supplies within an Irish catchment., EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-16975, https://doi.org/10.5194/egusphere-egu24-16975, 2024.

Katarzyna Styszko, Wioleta Bolesta, Jagoda Worek, Daniel Kaleta, Adam Nalepa, Justyna Pyssa, Karolina Cwynar, Zuzanna Prus, and Laura Frydel

The presence of pharmaceuticals in the aquatic environment is known to scientists and is constantly being investigated. Such micropollutants with bactericidal, virucidal, or fungicidal properties are commonly used in households, which results in their presence in raw sewage flowing to wastewater treatment plants. The content of pharmaceuticals may vary depending on the lifestyle of the inhabitants or the intensity of drug consumption. This study analysed the content of antibiotics, virucidal and fungicidal substances in raw and treated sewage from one of city located in southern Poland with a population equivalent of 680,000. Furthermore, the study was conducted in the summer and autumn-winter seasons.

Microplastics are one of the largest pollutants in the world. Since the 1970s, it has already existed, but there has been no better alternative than plastic. It is related to easy and cheap production, high availability, and specific properties of plastics, such as plasticity, chemical resistance, and lightness.

In the research, samples of stabilized sewage sludge were analyzed in terms of quantitative and qualitative analysis. The separation of microplastics was carried out in two stages. First, the sample matrix was digested with 15% hydrogen peroxide. The next step was density separation, where a saturated solution of calcium chloride was used. Separated microplastics were counted and their sources of origin were analyzed using a Raman confocal microscope and ATR FT-IR spectrometer. The samples were divided according to the month of their collection.
The production of organic-mineral fertilizers from sewage sludge is one of the ecological possibilities of their management. Pharmaceuticals and their derivatives, as well other micropollutants which get in the sludge during the treatment of wastewater, can be a problem. The negative impact of these micropollutants on the environment has been scientifically proven, and the pharmaceuticals and microplastics contained in the sludge may also be detected in fertiliser products.

Acknowledgments: Research supported by the Polish National Agency for Academic Exchange in the Bekker programme (no. PPN/BEK/2020/1/00243/) as well by the Polish National Science Centre (grant no. 2022/45/B/ST10/02108). Research was partially supported by the program ‘Initiative for Excellence – Research University’ for the AGH University of Krakow. Research supported under the Implementation Doctorate in the program of the Ministry of Science and Higher Education.

How to cite: Styszko, K., Bolesta, W., Worek, J., Kaleta, D., Nalepa, A., Pyssa, J., Cwynar, K., Prus, Z., and Frydel, L.: The occurence of pharmaceuticals and other micropollutants in wastewater treatment plant in the aspect of interaction with microplastics, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-20853, https://doi.org/10.5194/egusphere-egu24-20853, 2024.

Ashfeen Ubaid Khan, Giovanni Michele Porta, Monica Riva, and Alberto Guadagnini

Iodinated Contrast Media agents (ICMs), essential in diagnostic imaging, have seen a surge in usage within the healthcare sector. This rise has sparked significant environmental concerns, primarily due to the fact that ICMs can evade capture by standard wastewater treatment facilities, subsequently accumulating in environmental waters [1]. This situation underscores the urgent necessity to develop more sustainable and effective methods for the removal and recovery of ICMs from aquatic systems. Over the past ten years, the scientific community has been actively exploring various materials that could serve as potential adsorbents to extract ICMs from natural waters [2]. Although practical experiments have demonstrated the effectiveness of different adsorbents in removing ICMs, there is a pressing need for a detailed mechanistic understanding of the adsorption process. In response to this need, our research delves into the mechanistic adsorption behaviour of ICMs using a model of activated carbon, represented by a monolayer graphene surface. By focusing on the interactions at the molecular level, we aim to advance the predictive modelling of ICM adsorption and contribute to the development of more targeted and efficient removal strategies for these pervasive substances in our water systems. We utilized molecular docking and Density Functional Theory (DFT) simulations to scrutinize the adsorption process on a molecular level [3]. Additionally, we applied Quantitative Structure-Activity Relationship (QSAR) modelling to link molecular characteristics with adsorption energy, aiding in understanding the influential factors in the adsorption process and building a predictive model [4]. We developed a variety of QSAR models through the combination of Multiple Linear Regression and genetic algorithm. To evaluate and prioritize these models, our study employs Maximum Likelihood estimation alongside established evaluative criteria. These criteria aid in determining the probability for model accuracy of each model, thereby refining the QSAR methodologies. Based on our results for 24 ICMs involved in this study we observed the varying adsorption energies from -4.40 Kcal/mol (Methiodal) to -40.35 Kcal/mol (Iobitiridol) suggesting a selective adsorption of ICMs. We observed that van der Waals interactions such as π-π stacking to be the primary mechanism of adsorption. Our DFT results also highlighted a significant correlation between adsorption energy and the Molecular weight of the ICMs. Furthermore, based on our final QSAR model, we observed that structural properties such as molecular complexity, presence/absence of Iodine atoms and molecular complexity play a strong role in the adsorption of ICMs on the adsorbent.


1. Sengar, A., Vijayanandan, A., 2021. Comprehensive review on iodinated X-ray contrast media: Complete fate, occurrence, and formation of disinfection byproducts. Science of the total environment 769, 144846.

2. Dekker, H.M., Stroomberg, G.J., Prokop, M., 2022. Tackling the increasing contamination of the water supply by iodinated contrast media. Insights into Imaging 13, 30.

3. Orio, M., Pantazis, D.A., Neese, F., 2009. Density functional theory. Photosynthesis research 102, 443–453.

4. Roy, K., 2017. Advances in QSAR modeling. Applications in Pharmaceutical, Chemical, Food, Agricultural and Environmental Sciences; Springer: Cham, Switzerland 555, 39.

How to cite: Khan, A. U., Porta, G. M., Riva, M., and Guadagnini, A.: Mechanistic study of the adsorption of Iodinated Contrast Media agents on monolayer Graphene surface, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-21920, https://doi.org/10.5194/egusphere-egu24-21920, 2024.

Posters virtual: Mon, 15 Apr, 14:00–15:45 | vHall A

Display time: Mon, 15 Apr 08:30–Mon, 15 Apr 18:00
Chairpersons: Matthias Gassmann, Margaret Stevenson
Anju Joshy and Sudha Goel

Sulfamethoxazole is a sulfonamide class antibiotic commonly used to cure infections caused by bacteria in humans and animals. Sulfamethoxazole is considered a contaminant of emerging concern and is one of the most frequently found antibiotics in the environment. It has proven to be highly stable and persistent in the environmental matrices, with a half-life of more than 100 days in an aqueous environment under specific environmental conditions. This causes a severe threat to human and environmental health. The presence of residue of sulfamethoxazole in water matrices shows hazardous effects on aquatic life, affecting the physiological behaviour and reproductive capacity of aquatic organisms. Sulfamethoxazole also showed potential negative impacts on the microbial communities. The persistence of these compounds for an extended period in the environment leads to the formation of antibiotic-resistant genes in bacteria, which can affect the proper functioning of the ecosystem. In this current study, the effectiveness of the electrooxidation process on the removal of sulfamethoxazole using graphite electrodes was investigated. The effect of different parameters like the electrolysis time, current density, initial concentration of sulfamethoxazole, electrolyte concentration (NaCl or Na2SO4), and initial pH of the sample solution were evaluated. Out of the various parameters, it was found that current density (1-10 mA/cm2), electrolyte concentration (100- 500 mg/ L), and the electrolysis time (0-1h) are the key parameters that determine the efficiency of the electrooxidation treatment process. It was found that for the current density value of 10 mA/ cm2, within 45 min of electrolysis time, nearly 99% of the sulfamethoxazole degradation occurred. The possible sulfamethoxazole degradation mechanisms and resulting by-products were analyzed using the Liquid chromatography-mass spectroscopy (LC-MS). Degradation kinetics were also evaluated for the electrooxidation treatment process. The results from the current study showed that electrooxidation could be a favourable treatment technique for the removal of sulfamethoxazole from water matrices.

How to cite: Joshy, A. and Goel, S.: Electrooxidation for the removal of Sulfamethoxazole using graphite electrodes, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-983, https://doi.org/10.5194/egusphere-egu24-983, 2024.

Jaclyn Smith, Matthew Stocker, and Yakov Pachepsky

Cyanotoxins in agricultural irrigation waters pose a potential human and animal health risk. Cyanotoxins can be transported to crops and soil during irrigation; they can remain in the soils for extended periods and be absorbed by root systems. Spatial and temporal variations of cyanotoxin concentrations have been reported for various freshwater sources. However, little has been reported for agricultural irrigation ponds. The objective of this research is to determine if persistent spatial and temporal patterns of the cyanotoxin microcystin occur in agricultural irrigation ponds over several years. The study was performed at a commercial irrigation pond in Maryland, USA, during the 2022-2023 summer sampling campaign over a fixed spatial 10-location grid on 16 sampling dates. Microcystin concentrations were determined using ELISA microcystin-ADDA kits. Ten water quality parameters were obtained using fluorometry and in-situ sensing. Temporal and spatial persistence was assessed using mean relative differences (MRDs) between measurements in each location and averaged measurements across the pond on each sampling date. Positive (negative) MRDs were found in locations where concentrations were predominantly larger (smaller) than the pond’s average. Persistent spatial patterns of microcystin concentrations were found. The pond’s flow conditions and bank proximity to sample locations were indicative of the MRD values signs and amplitudes. The highest absolute values of correlation coefficients were found between microcystin and pH, and microcystin and phycocyanin. The lowest absolute values for correlation coefficients were found for CDOM and chl-a. Results of this work show that microcystin concentrations can follow stable spatial and temporal patterns in irrigation ponds over multiple years, indicating that water quality sampling for cyanotoxins and placement of water intake should not be arbitrary. Research of the spatiotemporal variability of other cyanotoxin concentrations as well as understanding the degree of site-specificity of cyanotoxin concentration relationships with water quality parameters presents an interesting research avenue.

How to cite: Smith, J., Stocker, M., and Pachepsky, Y.: Multiyear spatial and temporal variability of microcystin concentrations in an irrigation pond in Maryland, USA, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6395, https://doi.org/10.5194/egusphere-egu24-6395, 2024.

Seokmin Hong, Billie Morgan, Matthew Stocker, Jaclyn Smith, Moon Kim, Kyung Hwa Cho, and Yakov Pachepsky

Rapid and efficient quantification of E. coli levels is the important goal of the microbial water quality assessment. To address this, remote sensing and machine learning algorithms have been used recently. Application of these techniques encounter challenges from a limited number of samples and imbalances in water quality datasets. This study focused on estimating E. coli concentrations in a Maryland irrigation pond during the summer season. We utilized demosaiced drone-based RGB imagery across visible and infrared spectrum ranges along with 14 water quality parameters. Employing four machine learning algorithms (Random Forest, Gradient Boosting Machine, Extreme Gradient Boosting, and K-nearest Neighbor) under three scenarios, the research explored the utilization of only water quality parameters, both water quality and drone-based RGB data, and finally, only RGB data. Two data splitting methods, traditional random data splitting (ordinary data splitting) and quantile data splitting, were employed, with the latter providing a constant splitting ratio across each decile of the E. coli concentration distribution. Quantile data splitting resulted in a very good model performances and smaller differences between training and testing datasets. The RF, GBM, and XGB models, trained with quantile data splitting and hyperparameter optimization, resulted in R2 values above 0.847 for training and 0.689 for the test dataset. The integration of water quality and imagery data led to larger R2 values exceeding 0.896 for the test dataset. Shapley additive explanations (SHAP) highlighted the visible blue spectrum intensity and water temperature as the most influential inputs to the RF model. Overall, demosaiced RGB imagery proved to be a valuable predictor for E. coli concentration across the studied irrigation pond.

How to cite: Hong, S., Morgan, B., Stocker, M., Smith, J., Kim, M., Cho, K. H., and Pachepsky, Y.: Estimating Escherichia coli levels using drone-based RGB imagery and machine learning techniques, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6648, https://doi.org/10.5194/egusphere-egu24-6648, 2024.

William Johnson

The magnitude of repulsive barriers is of primary importance in colloid transport and surface interaction.  Experimentally observed colloid retention typically decreases and increases with rises and falls of repulsive barriers in response to decreases and increases in solution ionic strength, respectively. However, despite the observation that colloid attachment increases as barriers decrease, the mean field barriers remain hundreds to thousands of times too large to explain attachment.  Incorporation of nanoscale charge heterogeneity amplifies the rise and fall of repulsive barriers via expansion and contraction of the zone of colloid-surface interaction around heterodomains in response to decreased and increased ionic strength, respectively. This amplified impact of nanoscale heterogeneity explains experimentally observed attachment and introduces a stochastic nature to attachment that underlies explanation of non-exponential decreases of colloid concentrations with distance from source.  This success in prediction highlights the need for further efforts to directly characterize nanoscale heterogeneity.

How to cite: Johnson, W.: Title: How Expansion and Contraction of Colloid-Surface Interactions Drives Rise and Fall of Repulsive Barriers and Stochastic Colloid Attachment, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13551, https://doi.org/10.5194/egusphere-egu24-13551, 2024.