HS8.1.3 | Emerging contaminants and PFAS in soil-groundwater systems. Fate, risks, remediation and mitigation.
Emerging contaminants and PFAS in soil-groundwater systems. Fate, risks, remediation and mitigation.
Convener: Fritjof Fagerlund | Co-convener: Tissa Illangasekare
| Thu, 27 Apr, 14:00–15:45 (CEST)
Room 2.31
Posters on site
| Attendance Thu, 27 Apr, 10:45–12:30 (CEST)
Hall A
Orals |
Thu, 14:00
Thu, 10:45
During the last decades we have seen an exponential increase in new anthropogenic chemicals for all kinds of uses in society. Many of these are increasingly being detected at low levels in surface- and groundwater. Recent research on toxicity of chemicals such as per- and polyfluoroalkyl substances (PFAS), has raised concerns and led to stricter regulations in many countries. Contaminants such as PFAS, pharmaceuticals, pesticides, nanoparticles, plastics etc. may demonstrate low acute toxicity, but can still produce long-term adverse health effects even at very low levels of exposure. The ubiquitous presence of harmful, anthropogenic chemicals in the environment, some of which are “forever chemicals” that do not degrade naturally, requires immediate actions to reduce their release and spreading, better understand their transport and associated risks, and remove them from the environment.

These chemicals have produced many additional challenges for groundwater management, risk assessment and remediation. For many contaminants, the partitioning between different matrices such as the soil, groundwater and air as well as the interfaces between these phases is key to their mobility and fate as well as strategies for mitigation. Abiotic and biotic transformations and degradation influence persistence, partitioning between phases, mobility and risks. Many processes in both the groundwater and vadose zones need to be better understood and there is an urgent need for improved remediation and mitigation methods specifically designed for new contaminants. While contaminants of emerging concern are receiving attention in many places in e.g. Europe, North America and Australia, there are also large areas in the world where their occurrence and associated impacts on the environment and human health are poorly known. Finally, several challenges associated with the mitigation of traditional contaminants also remain.

This session seeks papers on process understanding through laboratory and field research, modeling, and site characterization to address new challenges and solutions associated with contamination of the soil-groundwater system by emerging contaminants and PFAS as well as unsolved challenges related to traditional contaminants.

Orals: Thu, 27 Apr | Room 2.31

Chairpersons: Fritjof Fagerlund, Tissa Illangasekare
On-site presentation
Dr. Benjamin Faigle, Dr. Hans-Georg Edel, and Bernhard Volz

The method of soil washing is currently the only economically feasible cleaning method for PFAS-contaminated soils on large scale.

A total of about 430,000 t of soil contaminated with PFAS and HCs was washed from August 2018 to October 2021 at the site of a former refinery in Bavaria. The cleaned soil could then be refilled at site-specific costs of about EUR 50 per ton. Since September 2022, Züblin Umwelttechnik GmbH has been operating another soil washing plant in Northern Germany, which was specially designed to treat soils contaminated with PFAS. Several hundred thousand tons of sandy soil with around 10% fines will be washed and refilled on site in the next years.

Data obtained from these two large-scale remediation projects are presented. The technical concept and challenges to treat 1,000 to 3,000 t of material per day are discussed, along with regulatory obstacles and the boundary conditions to process these quantities while limiting the emissions. A special focus lies on the heterogeneous nature of input material, with varying contaminant load, soil quality and soil structure as well as affiliated contaminants. In both attempts, the washing water is circulated in a closed water cycle, therefore elaborate treatment of sludge and polluted water is required.

One of the critical issues in soil washing is to optimise the washing process so that the washing liquid serves as the predominant contaminant sink. In this way, steady washing results are achieved, and all output fractions can be successfully processed while water consumption is kept to a minimum.

The complex nature of the contaminant itself, the multitude of singular PFAS substances and precursors, further complicate operation and controlling. Progress shows that soil washing can even be a viable tool to treat the fine fraction, and various strategies in different treatment steps have been tested on multiple scales, including several washing agents.

Since after treatment, the washed soils can be safely reused on site, large emissions from transportation and properly disposing the PFAS-materials is avoided while increasingly limited landfill space is maintained.

Future research is required for expanding the applicability of the method to highly challenging materials such as high fines and/or high organic content. Further projects for washing of PFAS contaminated soils in Europe are already in the planning stage.

How to cite: Faigle, Dr. B., Edel, Dr. H.-G., and Volz, B.: Successful treatment of PFAS-contaminated soils on large scale: practical experience with soil washing., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1373, https://doi.org/10.5194/egusphere-egu23-1373, 2023.

On-site presentation
Lauren P. Turner, David J. Patch, Bernard H. Kueper, and Kela P. Weber

Per- and polyfluoroalkyl substances (PFAS) are a diverse group of manmade, fluorinated organic chemicals that gained notoriety for their diverse application, widespread distribution in the environment and toxicity. One of the main sources of PFAS to the environment is through aqueous film forming foam (AFFF), intended for use on fuel fires. AFFF may enter the environment through system testing, training activities, emergency use or accidental release. When AFFF enters the environment PFAS readily adsorb to porous media through hydrophobic and electrostatic interactions. As a result, PFAS impacted porous media may act as a long-term source of contamination to groundwater, potentially influencing water resources and human health. There is a demand for effective treatment of PFAS impacted porous media. Ball milling has emerged as a potential treatment option for PFAS, however, the viability of treating AFFF impacted porous media has been seldom explored. In this work four AFFF formulations were amended onto silica sand and milled without and with the use of potassium hydroxide (KOH) as a co-milling reagent. Six hour milling trials were conducted using a planetary ball mill with stainless steel grinding media. Significant destruction of perfluorosulfonic acids, perfluorocarboxylic acids (PFCAs), fluorotelomer sulfonates, fluorotelomer betaines and fluorotelomer sulfonamido betaines was observed. With the use of KOH as a co-milling reagent the total PFAS destruction percentage in all four AFFFs exceeded 90%. Greater destruction of PFAS was observed in fluorotelomer dominant AFFFs when compared to perfluoroalkyl acid dominant AFFFs. PFCAs and soluble fluoride were identified as destruction byproducts. KOH as a co-milling reagent had the effect of reducing PFCA byproduct formation and increasing fluoride recovery in three of four AFFFs. Fluoride recoveries indicate PFAS molecule defluorination occurs by ball milling. When PFAS in AFFF is compared to PFAS destruction in single analyte trials, less destruction is observed, displaying the necessity of evaluating realistic AFFF contamination events over single or multi analyte mixtures.

How to cite: Turner, L. P., Patch, D. J., Kueper, B. H., and Weber, K. P.: Mechanochemical Destruction of Per-and Polyfluoroalkyl Substances in four Aqueous Film Forming Foam Formulations using amended Silica Sand and Potassium Hydroxide, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2916, https://doi.org/10.5194/egusphere-egu23-2916, 2023.

On-site presentation
19F-MRI measurements for PFAS adsorption and transport in chemically reactive porous media
Elisabeth Fries, Denis Courtier-Murias, Jaime Gil Roca, Pierre-Emmanuel Peyneau, Eric Michel, Khalil Hanna, and Béatrice Béchet
On-site presentation
Kevin G. Mumford, Justine E.F. Abraham, David J. Patch, Tohren C.G. Kibbey, and Kela P. Weber

Understanding how per- and poly-fluoroalkyl substances (PFAS) are transported is critical to site characterization, monitoring, risk assessment, and remediation planning.  This includes an understanding of PFAS retention and release at air-water interfaces.  These interfaces exist throughout the vadose zone, but can also exist as trapped air bubbles created by water table fluctuations, recharge, and biogenic gas production.  In addition to being directly applicable to transport through trapped gas zones at PFAS-impacted sites, laboratory experiments using emplaced trapped gas (quasi-saturated conditions) provide a controlled method to investigate PFAS behavior, including the effects of different PFAS, concentrations, and mixtures. 

In this study, a series of laboratory experiments was conducted using one-dimensional sand-packed columns (20 cm × 7 cm dia.).  Trapped air was emplaced by sequential drainage and imbibition to create quasi-saturated conditions.  Each experiment included separate injections of non-reactive tracer (NaCl) and PFAS solutions through both water-saturated and quasi-saturated columns.  A clean, low organic carbon sand was used to eliminate solid-phase sorption (verified through comparison of non-reactive tracer and PFAS breakthrough in the water-saturated columns) and to isolate the effect of air-water interfaces.  Experiments were conducted using single-component solutions of PFOA, PFOS and 6:2 FTS, as well as mixtures of those PFAS, at concentrations of 0.1-1 mg/L.  Experiments were also conducted using diluted aqueous film-forming foam (AFFF) solutions.  Measured retardation factors in triplicate experiments were used to estimate air-water partitioning coefficients.

The results showed that PFAS breakthrough was significantly delayed in the presence of trapped air bubbles.  Breakthrough delay was greater for PFOS than for PFOA or 6:2 FTS, and was greater for lower PFAS concentrations, for the range of concentrations used in these experiments.  For PFAS mixtures, differences in retention were sufficient to completely separate breakthrough (i.e., PFOA and 6:2 FTS achieved complete breakthrough prior to any PFOS arrival) even over short (20 cm) distances.  However, the behavior of each PFAS tested was altered by the presence of other PFAS, with PFOA and 6:2 FTS experiencing earlier breakthrough at higher concentrations (concentration overshoot) in the presence of PFOS.  Mixture effects were also observed for branched and linear PFOS isomers, and for AFFF solutions, which was further complicated by the presence of hydrocarbon surfactants.  The experimental results will be presented along with numerical simulations of PFAS transport subject to air-water partitioning, both to interpret the behavior of PFAS mixtures in experimental systems and to explore the implications of mixture transport in more complex field scenarios.

How to cite: Mumford, K. G., Abraham, J. E. F., Patch, D. J., Kibbey, T. C. G., and Weber, K. P.: PFAS transport through quasi-saturated porous media: Laboratory experiments and mixture effects, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-7942, https://doi.org/10.5194/egusphere-egu23-7942, 2023.

Emerging contaminants
On-site presentation
Linda Luquot, Maria Garcia Rios, Geoffroy Duporte, and Elena Gomez

The fate of emerging contaminants from runoff/storm waters in urban areas has aroused widespread concern as it poses a threat to the water managing. Contaminated water can reach, for instance, the river that passes through the area, contributing to the degradation of the aquatic ecosystem, or the aquifer that supplies drinking water to the community. In this framework, one of the objectives of the URBANWAT project is to evaluate the capacity of the Barcelona urban soil to retain the contaminants of emerging concern from runoff waters in order to propose an improvement of tools and criteria for groundwater management in urban areas.

To this aim, a set of batch and packed soil column experiments were performed. The soil selected for the study is located in the Barcelona urban area at 20 m depth and composed of 48 % quartz, 28 % albite and 24 % microcline. It is constituted by 91 % sand, 7 % silt and clay and 2 % gravel, being the sand particle size dimension the one selected to perform the column experiments. The resident water in contact with the soil was analysed by ICP-MS and has a conductivity of 723 µS/cm and pH of 7.9. A list of representative emerging contaminants has been selected from diverse pharmaceutical families and UV filters based on the concentration values found in the runoff waters of the Barcelona urban area.

The batch experiments were carried out first to verify if the soil already contained the target contaminants and second to know the soil sorption capacity. The target contaminants have different properties (pka, charge) that cause them to be sorbed with variable efficiency by the soil tested (80-100 % sorption for Paroxetine and Venlafaxine, 60-80 % for Cocaine and Caffeine, 40-60 % for Tradadol and Climbazole and low sorption (< 40 %) for a list of more than 15 emerging contaminants). Sorption capacities obtained in the batch experiments were also identified in the percolation tests, obtaining significantly different breakthrough curves for the studied target contaminants. By means of the percolation column experiments, the effect of the flow rate on the soil retention capacity was evaluated and the two main processes involved in the pollutants retention mechanism (sorption and biodegradation) were quantified to verify the specific contribution of each process to the global procedure. 

How to cite: Luquot, L., Garcia Rios, M., Duporte, G., and Gomez, E.: Evaluation of the Barcelona urban soil capacity for retention of emerging contaminants, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-6762, https://doi.org/10.5194/egusphere-egu23-6762, 2023.

On-site presentation
Lewis Semprini, Mohammad Azizian, Jacob Wortkoetter, and Michell Rasmussen

A novel aerobic process has been developed for the passive cometabolic treatment of contaminant mixtures in groundwater.  Our studies have focused on Rhodococcus rhodochrous ATCC 21198 that can concurrently oxidize 1,4-dioxane (1,4-D) and diverse mixtures of chlorinated aliphatic hydrocarbons (CAHs). We found that the short chain alkane monoxygenase (SCAM) responsible for the cometabolism of the contaminants is induced after grown on 1-butanol and 2-butanol, permitting the use of Slow Release Compounds (SRCs) that slowly hydrolyze to produce these alcohols.  Methods were developed to co-encapsulate the SRCs and ATCC 21198 in gellan-gum hydrogel beads. ATCC 21198 grows within the gellan-gum beads and upon diffusion into the beads the contaminants are transformed. In batch reactors containing the gellan-gum beads successive additions of a mixture of  1,1,1-trichloroethane (1,1,1-TCA_, cis-dichloroethene (cis-DCE), and 1,4-D were transformed for over 300 days, with the rates of cometabolism correlated with the rates of alcohol release, oxygen consumption and CO2 production. Continuous flow tests have been performed with columns packed with the gellan-gum beads. The columns mimic passive treatment that might be achieved using an in-situ permeable reactive barrier (PBR) constructed with the gellan-gum beads.  Over 99% removal of a mixture of 1,1,1-TCA, cis-DCE, and 1,4-D, each at influent concentration of 250 µg/L, was achieved with a hydraulic residence time of approximately 12 hours  The columns effectively transformed the contaminant mixture for over 600 pore volumes (300 days). The columns performance was negatively affected when cis-DCE was replaced by 1,1-dichloroethene (1,1-DCE), due to 1,1-DCE transformation product toxicity.  The column containing the SRC that produced 2-butanol was more negatively impacted by 1,1-DCE due to the lower biomass that developed in the gellan-gum beads. Studies are currently being performed in a 3-D physical aquifer model using a funnel-and-gate system with the co-encapsulated gellan-gum beads used to create a cometabolic permeable reactive barrier. 

How to cite: Semprini, L., Azizian, M., Wortkoetter, J., and Rasmussen, M.: Hydrogels that Co-Encapsulate Slow Release Compounds and Rhodococcus rhodochrous ATCC 21198 for the Aerobic Cometabolic Treatment of 1,4-Dioxane and CAHs, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10942, https://doi.org/10.5194/egusphere-egu23-10942, 2023.

On-site presentation
Paula Rodriguez-Escales, Sonia Jou, Jesus Carrera, Lurdes Martinez, Silvia Diaz-Cruz, Adria Sunyer, Gerard Quitana, and Cristina Valhondo

Ultraviolet filters (UVFs) are contaminants of emerging concern (CECs) produced and used in large quantities worldwide. They are constituents of a large number of personal care and hygiene products and other consumer goods. Benzophenones, such as benzophenone-3 (BP-3), benzophenone-4 (BP-4) and avobenzone (AVO), are among the most used. These compounds are characterized by being photo-stable and lipophilic. Although it is highly known the lipophilicity of these compounds, their monitoring in porous media is centered in the aqueous phase. Nevertheless, their high logKow make foreseeable the accumulation in more lipophilic phases such as biofilm or sedimentary organic matter. For that, in this work we have highly characterized a Managed Aquifer Recharge system with a very intensive monitoring of benzophenones and transformation products in the three phases: water, biofilm and sedimentary organic matter. Furthermore, we have contrasted our results with a numerical model, which was based on the partition of UVFs under equilibrium conditions. Our results show that biofilm acted as an additional environmental compartment favoring the retention and degradation of UVFs in porous media. Indeed, it played a central role in the fate of these compounds, controlling both sorption and biodegradation. With this we believe that the current understanding of the organic compounds fate should incorporate it as a new compartment capable of bio-accumulate these compounds.

How to cite: Rodriguez-Escales, P., Jou, S., Carrera, J., Martinez, L., Diaz-Cruz, S., Sunyer, A., Quitana, G., and Valhondo, C.: The role of biofilm as a bio-accumulator of Ultraviolet Filters in porous media, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12632, https://doi.org/10.5194/egusphere-egu23-12632, 2023.

On-site presentation
Benoit Pierre, Dollinger Jeanne, Lafolie François, Chabauty Florian, and Pot Valérie

The role of dissolved organic matter (DOM) in the transport of trace organic pollutants through the soil profile remains controversial. Several studies reported enhanced transport for nonpolar pesticides and other pollutants such as pharmaceuticals (e.g., Borgman & Chefetz 2013). It is generally hypothesized that DOM modifies the sorption properties of the contaminants through co-sorption and/or cumulative sorption (Totsche et al. 1997). Co-transport with DOM can also enhance the mobility of pollutants (Chabauty et al. 2016). Other authors reported little effect of DOM on both sorption or desorption of herbicides (e.g., Barriuso et al. 2011). To help elucidating the multiple roles of DOM, we developed the PolDOC model implemented in the VSoil modeling platform of INRAE. We took advantage of the modularity of the platform to couple available 1D water flow and solute transport models with novel reactivity modules for organic pollutants and DOM. Indeed, sink/source terms in the transport equation have been used to calculate the interactions between pollutants, DOM and the soil solid phase.

The model was designed to simulate the transport of organic pollutants in intact soil cores sampled in the Bt horizon of a cultivated Albeluvisol to which either a synthetic soil solution without DOM (SYNTH), a soil solution extracted from the top horizon (CONTROL) or a soil solution extracted from the top horizon of a neighbour plot receiving sewage sludge and green waste compost (SGW) were applied (Chabauty et al., 2016). In PolDOC, the organic pollutants can be transported either free or associated with DOM. To describe the multiple roles of DOM in the transport of organic pollutants we first simplified the wide spectrum of organic molecules which constitute DOM and distinguished two types of DOM with different reactivity: DOMBt produced by depolymerization of the organic matter in the Bt soil horizon, and DOMSURF, produced by depolymerization of the organic matter of the surface horizon.

The model was used to simulate the transport of both DOM types and three different organic pollutants: isoproturon (ISO), a mobile herbicide, epoxiconazole (EPX), a moderately mobile fungicide and sulfamethoxazole (SMX), a mobile antibiotic. Since pollutants are applied at the soil surface, we considered that organic pollutants will be more prone to interact with DOMSURF, which is rich in phenolic compounds. Physical non-equilibrium transport conditions were identified and quantified with PolDOC. Model showed that the Bt horizon acted as a sink to partly retain DOMSURF. While differences in ISO and SMX transport could be explained by different sorption reactivity with the soil solid phase, the increased leaching of EPX in presence of DOMSURF required the activation of co-transport with DOMSURF.


Barriuso, E., Andrades, M.-S., Benoit, P., and Houot, S. (2011) Biogeochemistry 106, 117–133.

Borgman, O., and Chefetz, B. (2013) Water Research 47, 3431–3443.

Chabauty F., Pot V., Bourdat-Deschamps M., Bernet N., Labat C., and Benoit P. (2016) Environmental Science and Pollution Research, 23, 7, 6907-6918.

Totsche, K.U., Danzer, J., and Kögel-Knabner, I. (1997). Journal of Environment Quality 26, 1090–1100.

How to cite: Pierre, B., Jeanne, D., François, L., Florian, C., and Valérie, P.: Assessing the multiple effects of dissolved organic matter on the transport of organic pollutants in subsoil horizons through a modular modeling approach, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12446, https://doi.org/10.5194/egusphere-egu23-12446, 2023.

On-site presentation
Efstathios Diamantopoulos, Daniel Bernado García-Jorgensen, Maja Holbak, Per Abrahamsen, and Hans Chr. Bruun Hansen

Plants produce a diverse array of toxic compounds which may be released by precipitation, that explains their wide occurrence in surrounding soil and water. This study presents the first mechanistic model for describing the generation and environmental fate of a natural toxin, viz.  ptaquiloside (PTA), a carcinogenic phytotoxin produced by bracken fern (Pteridium aquilinum L. Kuhn). The newly adapted DAISY model was calibrated based on two-year monitoring performed in the period 2018-2019 in a Danish bracken population located in a forest glade. Several functions related to the fate of PTA were calibrated, covering processes from toxin generation in the canopy, wash off by precipitation and degradation in the soil. Model results (2018-2019) show a good description of observed bracken biomass and PTA contents, indicating that toxin production can be explained by biomass and bracken development stage. The wash off is maximum in the middle of summer, coinciding with the moment of maximum biomass, fully developed canopy and highest PTA content. Model results show that only 4.4 % of the PTA produced in bracken is washed off by precipitation, from both canopy and litter. Once in the soil, PTA degrades rapidly, especially during summer due to the high soil temperatures. Leaching takes place in form of pulses directly connected to precipitation events, with maximum simulated concentrations up to 4.39 µg L-1 at 50 cm depth. Macropore transport is responsible for the events with highest PTA concentrations, contributing to 72% of the total mass of PTA leached. Based on the results, we identify areas with high precipitation and soils characterized by fast transport, as the most vulnerable to surface and groundwater pollution by phytotoxins

How to cite: Diamantopoulos, E., García-Jorgensen, D. B., Holbak, M., Abrahamsen, P., and Bruun Hansen, H. Chr.: Modeling the environmental fate of the natural toxin ptaquiloside: production, release and leaching to groundwater, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12856, https://doi.org/10.5194/egusphere-egu23-12856, 2023.

On-site presentation
Marta Inés Llamas, Pablo Jiménez-Gavilán, Juan Antonio Luque-Espinar, José Benavente-Herrera, Lucila Candela, Mónica Sanmiguel-Martí, Javier Rambla-Nebot, José Luis Aranda-Mares, and Iñaki Vadillo-Pérez

The anthropogenic organic contaminants contemplated in the environmental legislation, as well as those of emerging concern, threaten the quality of water resources to a degree that remains largely unknown. Contaminant exposure in the aquatic environment is a crucial element if a full understanding of the risk is pursued. There are still many uncertainties about the occurrence of organic contaminants and their behavior in the hydro(geo)logical media in large scale areas. The case study of the unconfined aquifer of the Granada Plain (approximately 200 km2) is presented here. Two groundwater and surface water monitoring campaigns were conducted (March 2017 and June 2018). Water samples were analysed for (i) 171 organic contaminants (e.g., pesticides, pharmaceuticals, drugs of abuse, PAHs); (ii) major and minor ions (Ca2+, Mg2+, Na+, K+, Cl-, SO42-, HCO3-, NO3-) and (iii) isotopes of the water molecule (δ18O, δ2H) and δ13C from the dissolved inorganic carbon. Additionally, in situ measurements of physico-chemical parameters (pH, temperature, electrical conductivity, redox potential and dissolved oxygen) were carried out. In total, 41 organic pollutants were detected, at least once: 17 pharmaceuticals or drugs of abuse, 21 pesticides or their metabolites and three PAHs. Statistical tests confirmed the significance of seasonal changes for some of these parameters (e.g., EC, Cl-, F-, δ18O, δ13C), revealing the influence from snowmelt water input on streams and the intensification of irrigation. In March 2017, the group of pesticides (largely represented by triazines) predominated, whereas the frequency of detection of pharmaceuticals increased substantially in June 2018. Based on the obtained results, a qualitative evaluation has been made to suggest four main factors affecting the spatial and seasonal variation of organic pollutants in the aquifer: (i) the variation of the unsaturated zone thickness; (ii) the river-groundwater hydraulic connection; (iii) the hydraulic gradient; and (iv) the anthropogenic factor determining the period of contaminant release throughout the year and wastewater management practices. The river-groundwater hydraulic connection can be especially important in the case of those contaminants whose main path of entry into the aquatic environment occurs through wastewater discharge into streams (i.e., pharmaceuticals).

How to cite: Llamas, M. I., Jiménez-Gavilán, P., Luque-Espinar, J. A., Benavente-Herrera, J., Candela, L., Sanmiguel-Martí, M., Rambla-Nebot, J., Aranda-Mares, J. L., and Vadillo-Pérez, I.: Hydrogeological, hydrodynamic and anthropogenic factors affecting the spread of pharmaceuticals and pesticides in water resources of the Granada plain (Southern Spain), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15414, https://doi.org/10.5194/egusphere-egu23-15414, 2023.


Posters on site: Thu, 27 Apr, 10:45–12:30 | Hall A

Chairpersons: Tissa Illangasekare, Fritjof Fagerlund
Eva Weidemann, René Lämmer, Bernd Göckener, Mark Bücking, and Matthias Gassmann

Per- and polyfluoroalkyl substances (PFAS) are organic contaminants which are ubiquitous in the environment and anthropogenically manufactured. The presence of PFAS in the environment is connected to their production, use and disposal, i.e. the whole life cycle. Contact with organisms can have adverse effects such as toxicity, bioaccumulation and carcinogenicity depending on the specific compound. There are several thousands of different PFAS with different structures and properties, which differ in their environmental behaviour as well. One example is biotransformation, which is not observed for all PFAS, such as the persistent group of perfluoroalkyl acids (PFAAs). Other PFAS, such as polyfluoroalkyl phosphate diesters (diPAP), act as precursors which are transformed into the stable PFAAs. When released to the environment, it is important to have information about the relevant processes such as adsorption, transformation and formation of non-extractable residues (NER).

In this study, leaching simulations were performed using a multi-objective parameter optimization algorithm (caRamel) in R connected to the MACRO 5.2 model. The simulation is based on a lysimeter study with two transformable precursors (6:2 diPAP and 8:2 diPAP) under near-natural conditions and a duration of two years. Objective functions of masses in the percolation water, in the soil and in the grass, planted on the lysimeter, were optimized simultaneously for diPAPs and related persistent PFAA metabolites. The model setup was based on past leaching simulations of soil columns with similar soils, the same substances and the same study duration. A comparison of lysimeter and soil column simulations indicates temperature-affected transformation kinetics, which could be related to the microbial activity. In further studies, the influence of environmental parameters on the transformation of diPAPs should be focussed to evaluate the results of this study.

How to cite: Weidemann, E., Lämmer, R., Göckener, B., Bücking, M., and Gassmann, M.: Simulation of diPAP Transformation and Related Metabolite Leaching Under Near-Natural Conditions, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5202, https://doi.org/10.5194/egusphere-egu23-5202, 2023.

Tissa Illangasekare, John Stults, Chris Higgins, and Charles Schaefer

Per- and polyfluorinated alkyl substances (PFASs) are a large class of anthropogenic compounds which are widespread emerging contaminants of concern in the environment. Their environmental recalcitrance, long-term stability, high mobility, and toxicity make these compounds a significant threat to groundwater sources. Many PFASs are surfactants, imparting properties that impact their mobility in the subsurface.  In the last several years, progress has been made in the understanding of how these chemicals are retained and mobilized in the unsaturated zone by focusing on the mechanisms of partitioning from the water to the water-air interfaces within the pores. The fundamental knowledge of the mechanisms contributing to retention has been primarily studied using packed, one-dimensional laboratory columns with sands under highly idealized conditions. Few studies where either field soils are used in columns or pilot-scale field tests are conducted been reported or are in progress. Even without the chemical and physical complexities associated with the behavior of PFASs, modeling water infiltration and chemical transport in the field remains a challenge. Several factors, including spatial variability of the soil characteristics from pore to macro-scale, contribute to this challenge.  The soil in natural field systems where contamination has occurred is a mixture of silt, clay, and sand. The structure of the soil in its natural form changes within the vertical profile due to different levels of compaction and disturbance resulting from vegetation growth, decay, soil fracturing, bioturbation, etc. In addition, the texture variability results in heterogeneity at different spatial scales from pores to soil pockets (lenses) and layering (stratification). The water infiltrating through the soil carries the PFAS from the surface soils, where the chemicals have been introduced and deeper into the soil profile before reaching the water table, contaminating the groundwater. The soil disturbances and heterogeneity result in non-uniform water pathways, thus affecting the retention, mobilization, and transport. Additional challenges to PFASs that behave as surfactants come from spatial variability of the soil-water interfaces resulting from immobile zones that change spatially and dynamically, depending on the infiltration rates.   This paper discusses the conceptual issues that need to be addressed in transferring the knowledge and parameters determined using laboratory column studies where breakthrough data (BTC) are analyzed using many simplifications. Based on our experience of other problems of transport of chemicals in the vadose zone, the feasibility, challenges, and limitations of using multi-scale testing and modeling approach are presented.  




How to cite: Illangasekare, T., Stults, J., Higgins, C., and Schaefer, C.: Issues of Upscaling from Laboratory Columns to Field-scale Retention and Transport of Poly- and Perfluoroalkyl Substances in the Unsaturated Zone, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-10948, https://doi.org/10.5194/egusphere-egu23-10948, 2023.

Fritjof Fagerlund, Nicola Messinger, Lutz Ahrens, Stefan Bertilsson, Dan Berggren Kleja, Jonny Bergman, Qusay Naji, Gareth Leonard, Sara Sahlin, and Sofia Westling

Per- and polyfluoroalkyl substances (PFAS) are very challenging to remediate and remove from contaminated soil and groundwater. While there is ongoing research on the topic, there is still a lack of cost-efficient techniques for in-situ or on-site PFAS degradation, largely due to the extreme recalcitrance of perfluoroalkyl acids (PFAAs), which are often the end-products of environmental PFAS transformations. Microbial degradation is a key process for the removal of many organic contaminants from the environment. There is also growing evidence from laboratory studies that under the right conditions microbial degradation of PFAS, including PFAAs occurs, indicating that microbial degradation potentially can be developed into a useful PFAS remediation method. At the same time, there is a lack of knowledge about microbial PFAS-degradation processes and the organisms involved. Improved knowledge of PFAS biodegradation is also necessary to better understand PFAS mass transport from contaminated hotspots.

Here, the aims, methods and preliminary results of a newly started research project: “Microbial degradation of PFAS for remediation of contaminated soil and groundwater” (bioPFAS) are presented. The project aims at investigating how conditions for microbial degradation can be stimulated at PFAS-contaminated sites, the degree and rates of degradation that can be achieved, the main environmental factors governing degradation and the organisms involved. Systematic laboratory studies will be performed using a large number of incubations to identify and characterize PFAS-active microbial strains and consortia as well as governing environmental factors. PFAS transformations will be quantified and characterized and the potential for field application will be investigated first in soil columns and subsequently in a small field demonstration test. Geochemical and PFAS-transport models will be used to further investigate the feasibility of microbial PFAS degradation and any associated risks.

How to cite: Fagerlund, F., Messinger, N., Ahrens, L., Bertilsson, S., Berggren Kleja, D., Bergman, J., Naji, Q., Leonard, G., Sahlin, S., and Westling, S.: Microbial degradation of PFAS for remediation of contaminated soil and groundwater (bioPFAS), EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-12570, https://doi.org/10.5194/egusphere-egu23-12570, 2023.

Emerging contaminants
Nitai Amiel, Ishai Dror, and Brian Berkowitz

Rare earth elements (REEs) play a crucial role in manufacturing high-tech products and developing various technologies, including those related to the transition to clean energy. Consequently, there has been a significant increase in REE production, which has the potential to contribute to the contamination of groundwater systems that are highly susceptible to industrial pollution. Groundwater REE contamination, specifically in coastal aquifer systems, could affect large populations that rely on that water for drinking and domestic use. In this study, we conducted column transport experiments using five representative coastal aquifer materials to understand better the mechanisms that control REE mobility and retention in coastal aquifers. These experiments were conducted by adding humic acid (HA) to the REE solution under fresh and brackish water conditions. The REEs were shown to be most mobile in sand samples, followed by two types of low-calcareous sandstone and one type of high-calcareous sandstone, and least mobile in red loamy sand. The mobility of REEs, found in solution primarily as REE-HA complexes, was controlled mainly by the retention of HA, which increases with ionic strength. Furthermore, it was found that the presence of carbonate and clay minerals reduces REE mobility due to enhanced surface interactions. The enrichment of middle-REE (Nd-Gd) was observed in the sand samples, while heavy-REE (Tb-Lu) enrichment was observed in the calcareous sandstones and the red loamy sand. This change in REE pattern likely originates from the release of carbonate ions from the carbonate minerals that stabilize heavy-REEs compared to middle-REEs.

How to cite: Amiel, N., Dror, I., and Berkowitz, B.: Mobility and Retention of Rare Earth Elements in Coastal Aquifers, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-5316, https://doi.org/10.5194/egusphere-egu23-5316, 2023.

Leonardo Costa and Paolo Salandin

In the Treviso province (Veneto, Italy) most of the drinking water (nearly 60 %) is supplied from wells located in the northern piedmont area, where agricultural activities are developed using chemical plant protection products (chemical PPPs). In this area the aquifer interested by the groundwater extraction is unconfined, making the subsurface water resource intrinsically vulnerable to any PPP or PPP residue (metabolite) leaching from the agricultural soil to the groundwater table, and raising concerns about the consequences of a possible groundwater contamination on the health of the local inhabitants.

To protect the drinking water resource, in 2019 the Veneto Region provided a technical framework for the definition of the wellhead protection areas (WHPAs, Resolution 1621) in accordance with the EU directives 2000/60 and 2006/118, related to the establishment of safeguard zones for the water bodies used for drinking water supply.  In the WHPAs the use of PPPs is only allowed when accounting for the vulnerability of the groundwater and the well extracting water for human consumption. 

To define the vulnerability of wells supplying drinking water, a procedure that considers the tridimensional behavior of a possible contaminant is suggested, taking into account the mobility of the chemical species across the vadose zone, the total amount of PPPs applied on the soil, and combining the probability of contaminant infiltration with the groundwater pathlines reaching the well.

An application has been developed in the piedmont area of the Treviso province where a geospatial analysis of the vine-specific PPPs sales data identified over 30 WHPAs potentially affected by the PPPs use. 

The 3D vulnerability assessment couples the position of the vulnerable WHPAs retrieved from the geospatial analysis with 1) the data related to the infiltration capacity of agricultural and not-agricultural unsaturated soils in the piedmont area of the Treviso province, 2) the mobility of the vine-specific PPPs, and 3) the groundwater pathlines in the superficial phreatic aquifer obtained by physically-based numerical modeling.

This research has been funded by the contribution from the UNI-IMPRESA 2021 joint research project (Centre of Hydrology ‘Dino Tonini’ - University of Padua, Alto Trevigiano Servizi Spa, Piave Servizi Spa): Subsurface Water quality and Agricultural pracTices monitoring 2 (SWAT-2).

How to cite: Costa, L. and Salandin, P.: Tridimensional vulnerability assessment of wells supplying drinking water in agricultural areas, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15708, https://doi.org/10.5194/egusphere-egu23-15708, 2023.

Yingjie Chen, Huanfang Huang, Wenwen Chen, Xuelian Huang, Zhe Qian, and Shihua Qi

N-nitrosamines have been frequently detected in natural waters as a kind of nitroso compound with significant carcinogenic effects on humans. In remote agricultural areas, groundwater is often consumed directly due to inadequate water supply systems, necessitating the investigation of the occurrence, sources, and cancer risk of N-nitrosamines in the groundwater of agricultural areas. This study identified eight N-nitrosamines in groundwater and river water in the Jianghan Plain, a popular agricultural area in central China. The total concentrations of N-nitrosamines in the groundwater and river water were <2.3~61 ng/L and 3.2~10 ng/L, respectively. N-nitrosodimethylamine (NDMA), N-nitrosodiethylamine (NDEA), N-nitrosomorpholine (NMOR), N-nitrosopyrrolidine (NPYR), and N-nitrosodi-n-butylamine (NDBA) were detected in groundwater, with the main compound being NDMA (up to 52 ng/L). These N-nitrosamines were also detected in river water at comparable concentrations. The significant negative correlations between N-nitrosamines and water temperature/DO indicated that aerobic biodegradation had an influence on the N-nitrosamine distribution. Ammonium (NH4+) was proven not to be a N-nitrosamine precursor, and it rarely reacts with the precursors to form N-nitrosamines. NH4+ and NDBA have similar sources in the JHP. Nitrite (NO2-) could consume active hydroxyl radicals, which played a decisive role in forming N-nitrosamines from the ozonation of secondary amines, rather than react with secondary amines when the concentration of NO2- was low. In the case of high NO2- concentrations, NO2- reacts with amines in the environment to form N-nitrosamines. The concentrations of NDMA, NDEA, and NDBA precursors were higher in groundwater than in river water, as suggested by the formation experiment. Redundancy analysis and multiple linear regression analysis results showed the primary source of N-nitrosamines by applying nitrogen fertilizer and specific N-nitrosamines such as NPYR carried by pesticides in groundwater. The average (1.08 × 10-5) and maximum (8.18 × 10-5) total cancer risk values of detected N-nitrosamines were higher than the accepted risk level (10-5), suggesting a potential carcinogenic risk of contaminated groundwater. To minimize N-nitrosamine contamination in the groundwater of agricultural areas, further research on selecting pesticides and fertilizers that are heavily used is urgently needed.

How to cite: Chen, Y., Huang, H., Chen, W., Huang, X., Qian, Z., and Qi, S.: Occurrence, fate, and risk assessment of N-nitrosamines in groundwater and river water in an agricultural area, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1816, https://doi.org/10.5194/egusphere-egu23-1816, 2023.

Chiara Cappelli, Mònica Rosell, Clara Torrentó, María Usieto, and Albert Soler Gil

The acknowledgment of the serious hazard caused by the massive use of pesticides and other industrial and commercial products containing organochlorine compounds has prompted the search of the best strategy for the remediation of aquatic and terrestrial environments. Organochlorine compounds are persistent contaminants present in soils and water that easily bio-accumulate and bio-magnify becoming a threat for human health1.  The in situ chemical oxidation (ISCO) has proven to be an effective method for the decontamination of chlorinated solvents2. The ISCO implementation needs specific oxidant-activation conditions that are often difficult to maintain. In a previous study, inert urban waste (concrete residue) was used in a pilot system of circular economy to induce alkaline conditions in interception trenches installed in the unsaturated zone of a contaminated bedrock aquifer3. In the present study, a scaled down set-up was used to produce preliminary data on the solid reactivity and solution changes upon the application of an oxidant, persulfate, which requires alkaline activation. Flow-through columns were filled with grinded concrete waste that was allowed to react with water extracted from the trenches and enriched with persulfate. The results set the basis for the correct in situ application of the planned remediation method.  

1. Islam, M. A.; Amin, S. M. N.; Rahman, M. A.; Juraimi, A. S.; Uddin, M. K.; Brown, C. L.; Arshad, A. Environmental Nanotechnology, Monitoring & Management 2022, 18, 100740.

2. Krembs, F. J.; Siegrist, R. L.; Crimi, M. L.; Furrer, R. F.; Petri, B. G. Groundwater Monitoring & Remediation 2010, 30, (4), 42-53.

3. Torrentó, C.; Audí-Miró, C.; Bordeleau, G.; Marchesi, M.; Rosell, M.; Otero, N.; Soler, A. Environmental Science & Technology 2014, 48, (3), 1869-1877.

How to cite: Cappelli, C., Rosell, M., Torrentó, C., Usieto, M., and Soler Gil, A.: Experimental study of a circular economy system for the oxidation treatment of organochlorine compounds, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-1864, https://doi.org/10.5194/egusphere-egu23-1864, 2023.

Maria Mursaikova, Michal Kuraz, and Zbynek Hrkal

Artificial sweeteners (ASs) are a class of low-level emerging organic contaminants (EOCs) that recently appeared in aquatic environment around the world due to its increased worldwide consumption. Once ingested by humans, the major amount of these artificial sweeteners excretes unchanged from the body and is transfered to the water environment through sewage systems. Consequently, artificial sweeteners are posing a new threat and a concern is growing over the contamination of a water environment.

Due to its stability and mobility, ASs have long been considered as ideal tracers for a detection of domestic wastewater in natural water bodies, particularly groundwater. However, other previously conducted studies show that ASs are vulnarable to degradation under certain conditions. Therefore, fate, behavior, and ecotoxicological side of artificial sweeteners within waterbodies still remain ambiguous.

Recently, ASs were also detected in the central part of the Czech Republic in the area of Káraný waterworks with a river bank filtration system. Considerable attention has been given to one of the widely used artificial sweetener - Acesulfame-K, which has been detected as a predominant contaminant in numerous pilot site across Europe and other worldwide countries.

In our research we focus to pilot site of Jizera river, Czechia, where Acesulfame-K was detected in ranges 72.0 to 591.0 ng/l. Although the systems of riverbank filtration eliminate the presence of many anthropogenic contaminants in water, Acesulfame-K was still detected in groundwater with concentrations up to 75 ng/l.

Based on available field and literature data, a two-dimensional large-scale hydraulic and transport model was developed using DRUtES software. For Acesulfame-K, the following first-order degradation rate was identified: λ = 0.0358 ± 0.0022 1/d. This result was further confirmed here by a small-scale laboratory experiment, where we mimicked conditions of our pilot site groundwater aquifer.

How to cite: Mursaikova, M., Kuraz, M., and Hrkal, Z.: Degradation behaviour of the Artificial sweetener-Acesulfame-K during riverbank infiltration system. A case study from Karany waterworks, Czech Republic., EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-2646, https://doi.org/10.5194/egusphere-egu23-2646, 2023.

Krzysztof Dragon, Roksana Kruć-Fijałkowska, Dariusz Drożdżyński, and Józef Górski

Emerging contaminants (e.g. pharmaceuticals, personal care products, drugs or pesticides) are increasingly detected in aquatic environments. The most apparent contamination source of river water pollution by pharmaceuticals are sewage treatment plant stations that discharge treated sewage effluent to the rivers. The river bank filtration systems (RBF) can effectively remove these contaminants from polluted river waters. The two RBF sites were examined for pharmaceuticals occurrence that are located in the Warta River valley (Poland): Śrem waterworks located upstream and Gorzów waterworks located downstream from Poznan city. The water samples for pharmaceuticals investigation (114 substances in total) were taken from the river and from four continuously pumped wells in each site. Two wells at a close distance from the river were chosen at each site (40-50 m) and two wells located at a greater distance from the river (70 m in Śrem and 110 m in Gorzów). A visible increase in pharmaceutical concentration was observed in the river water. The sum of pharmaceuticals concentration is 8151 ng/l in the Śrem location, while in the Gorzów location, the sum of pharmaceuticals concentration is 9142 ng/l. Most probably, this increase is caused by the influence of treated sewage effluent from Poznań city and towns and villages located along the river. A considerable differentiation in pharmaceuticals removal rate was observed. In the Śrem site the sum of pharmaceuticals concentration in wells is between 657 ng/l and 3290 ng/l, while in the Gorzów site despite the higher concentrations of pharmaceuticals in the river, the pharmaceuticals were detected only in one well located at a close distance from the river (two substances at a total concentration of 92 ng/l). The research presented proves a very different rate of pharmaceuticals removal even on sites located at similar hydrogeological conditions and demonstrates the necessity of its monitoring, especially in groundwater that is strongly influenced by river water contamination (like RBF sites). This work has received funding from the National Science Centre of Poland (grant no. 2021/41/B/ST10/00094).

How to cite: Dragon, K., Kruć-Fijałkowska, R., Drożdżyński, D., and Górski, J.: The differentiation of pharmaceutical concentrations at two river bank filtration sites located in Warta River valley (Poland) - preliminary results, EGU General Assembly 2023, Vienna, Austria, 23–28 Apr 2023, EGU23-15967, https://doi.org/10.5194/egusphere-egu23-15967, 2023.