HS8.1.8

Recently an new microparticle tracer has been developed for investigating in stream-mass transport: a silica coated synthetic-DNA-tagged microparticles with a superparamagnetic core (SiDNAMag). SiDNAMag particles can be easily recovered by magnetic separation, with high DNA signal amplification by Quantitative Polymerase Chain Reaction (qPCR). However, with the presence of natural colloids, particulate matter and river bed sediments, SiDNAMag are likely to undergo complex interaction processes besides dispersion and advection. Moreover, little has been known for the possible sink sources of SiDNAMag tracer mass loss during transport in river waters.

In this research the focus is on investigating the transport behaviour of the SiDNAMag particle as a potential hydrological tracer. The behaviour of the SiDNAMag particles will be compared to those of solute tracers (NaCl) and silica microparticles in terms of breakthrough curves and mass recoveries, by performing open channel injection experiments in laboratory environment. The resulting breakthrough curves will be interpreted with a 1-D advection and dispersion model. Possible interactions and mass loss will be examined by performing batch and injection experiments in different river water types with the presence of river bottom sediments.

How to cite: van Rhijn, F., Tang, Y., Foppen, J. W., and Bogaard, T. A.: Magnetic DNA-based microparticle as a hydrological tracer in river-water tracing experiments, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14372, https://doi.org/10.5194/egusphere-egu21-14372, 2021.

The release of biochar colloids considerably affects the stability of biochar in environment. Currently, information on the release behavior and suspension stability of biochar colloids in real soil solutions is scarce. In this study, 20 soils were collected from different districts in China and the release behavior of biochar colloids and their suspension stability in soil solutions were systematically examined. The results showed that both pyrolysis temperature and biomass source had important effects on the formation of biochar colloids in soil solutions. The formation amount of biochar colloids from low pyrolysis temperatures (400 ℃) (average amount of 9.33–16.41 mg/g) were significantly higher than those from high pyrolysis temperatures (700 ℃) (average amount of less than 2 mg/g). The formation amount of wheat straw-derived biochar colloids were higher than those of rice straw-derived biochar colloids probably due to the higher O/C ratio in wheat-straw biochar. Further, biochar colloidal formation amount was negatively correlated with comprehensive effect of dissolved organic carbon, Fe and Al in soil solutions. The sedimentation curve of biochar colloids in soil solutions is well described by an exponential model and demonstrated high suspension stability. Around 40% of the biochar colloids were maintained in the suspension at the final sedimentation equilibrium. The settling efficiency of biochar colloids was positively correlated with comprehensive effect of the ionic strength and K, Ca, Na, and Mg contents in soil solutions. Our findings help promote a deeper understanding of biochar loss and stability in the soil-water environment.

How to cite: Fang, J.: Release and sedimentation behaviors of biochar colloids in soil solutions, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-5285, https://doi.org/10.5194/egusphere-egu21-5285, 2021.

This study examines the effects of soil organic matter (SOM) and water content on the transport of five selected pharmaceutical and personal care products (PPCPs, ibuprofen, carbamazepine, bisphenol A, tetracycline, and ciprofloxacin) in four natural soils with different SOM contents. Batch isotherm experiment results showed that SOM effect was very significant for positively charged tetracycline and ciprofloxacin, relatively significant for non-dissociated carbamazepine and bisphenol A and insignificant for negatively charged ibuprofen in the soils. Transport results showed that neither tetracycline nor ciprofloxacin moved through the saturated and unsaturated soil columns, demonstrating their very limited mobility in soils as a result of significant electrostatic attraction independent of SOM and water conditions. Overall, higher SOM content and lower water content were favorable to the retention of ibuprofen, carbamazepine and bisphenol A in the soils. The effect of water content was not significant in the SOM-removed soils. The SOM could increase the kinetic (type 2) adsorption of PPCPs at the solid-water interface (SWI), and the air phase could increase the instantaneous (type 1) adsorption of PPCPs at the air-water interface (AWI). This result suggests that lowering water content could greatly enhance the adsorption of PPCPs that had high affinities to soils and vice versa. This study provides an important implication that AWI and SWI might have a nonlinear relationship in promoting the adsorption and reducing the mobility of PPCPs under unsaturated flow conditions.

How to cite: Chen, X., Dai, Y., and Zhuang, J.: Synergistic Effects of Unsaturated Flow and Soil Organic Matter on Retention and Transport of PPCPs in Soils, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1861, https://doi.org/10.5194/egusphere-egu21-1861, 2021.

Veterinary Pharmaceuticals (VPs) are used world-wide to cure or prevent illness of animals, and increasingly investigated in view of emissions into the environment. It is known that environmental routes of VPs are complex while transport rates and persistence are not yet well established. Our investigation focuses on the route till application of VPs in (liquid) manure to soil. To characterize this for the Netherlands, we investigated national usage of 4 livestock sectors (dairy cow, veal calf, sow and fattening pig), as well as animal excretion rates prior and degradation during slurry manure storage. This has been done for 12 antibiotics, 4 antiparasitic drugs and one hormone. An inventory of data bases and taking into account data reliability, revealed for almost all substances a reduction of quantities administrated to the animals during the period 2015-2018. Literature review on excretion rates identified that there is still insufficient information, despite that those rates directly influence the VP portions in the environment. Our developed storage model showed that VPs concentrations during a period of 6 months could reduce by a factor as large as 60 and that the fractions present in that manure are highly dependent on animal type, quantity of produced manure and substance degradation rates. At the same time, our predicted after-storage concentrations were found to be comparable with the reported measurements available for some parts of the Netherlands. Considering that similar manure types are applied on arable lands and grasslands in considerable quantities in many other countries, our approach and results may represent a good foundation for further research on the environmental fate of VPs.

How to cite: Rakonjac, N., van der Zee, S., Wipfler, L., Roex, E., and Kros, H.: Use of Veterinary Pharmaceuticals and Application via Manure Slurries to Soil in the Netherlands, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-6591, https://doi.org/10.5194/egusphere-egu21-6591, 2021.

Colloids in the environment are defined as suspended particles in the size range of 1 nm to 10 microns. Both organic matter and antibiotics leached from animal manures applied to farmland may pose a pollution risk of groundwater. Manure colloids, which are mainly composed of dissolved organic matter (DOM), have been known to play an important role in facilitating transport of various strongly-sorbing contaminants in subsurface environments. Research on co-transport behavior of manure colloid DOM and antibiotics is lacking. In the present study, the effects of colloidal DOM derived from pig manure and chicken manure on the transport of different antibiotics were examined in a cropland soil and an orchard soil. According to the breakthrough curves obtained for repacked soil columns (2.5 cm in diameter, 15 cm in height) under a simulated rainfall intensity of 20 mm/h, florfenicol was highly mobile and leached out almost simultaneously with the water flow tracer Br^– for the cropland soil, which exhibited an 11%-23% higher leaching capacity than for the orchard soil. On the other hand, norfloxacin and tylosin did not penetrate through the column and most of their residues were retained in the top soil layer. Pig manure DOM delayed the breakthrough of florfenicol by 0.07-0.13 pore volume and increased its residues by 15%-26% as a result of enhanced retention through a co-sorption mechanism, and similar effects of chicken manure DOM were observed.

How to cite: Tang, X., Liu, C., Luo, F., Li, S., and Yang, H.: Effects of colloidal manure DOM on the transport of antibiotics in calcareous soils, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9781, https://doi.org/10.5194/egusphere-egu21-9781, 2021.

Soil degradation is a global issue, as the demand for food and feed consumption is growing rapidly every day, and agricultural land needed for their production is declining rapidly. The UN reports that 24 billion tons of fertile land are lost every year. One of the most important parameters causing and maintaining soil fertility is the presence of water-stable macroaggregates (> 0.25 mm) with a developed porous structure. In natural soil, aggregate formation occurs under the following main processes – coagulation with polyvalent cations, “glueing”/cementation under the action of mineral amorphous "glues" (silica, metal oxides/ hydroxides) and organic amphiphilic substances (microbial exopolymers and humic substances). In this research work we estimated the impact of bio-nanocomposite and its individual constituents with structure forming ability on the remediation efficacy of a degraded soil model sample.
The bio-nanocomposite was synthesised from active sludge. The composition of the bio-nanocomposite includes mineral matter – 36 %, organic matter – 64 %, humic acids, fulvic acids, ammonifying bacteria, nitrate-assimilating bacteria, actinomycetes, fungi, and metal nanoparticles in form of insoluble or sparingly soluble salts. To assess the effect of the concentration of bio-nanocomposite on the aggregation of soil colloids, the nanocomposites were added to the model soil system in concentrations of 1%, 2.5%, 5%, 10%, 20% and 50%, and compared with control unenriched soil.  The dynamics of soil colloids aggregation was assessed by the value of the optical density of aqueous suspensions at four months. The results indicate a correlation between the concentration of the introduced bio-nanocomposite and the degree of soil colloids aggregation – up to 70% after 2 months of incubation and up to 80% after 4 months. Analysis of the impact on the structure-forming processes of individual constituents of the bio-nanocomposite showed that nanoparticles of polyvalent metals made the most significant contribution (82 %), humic and fulvic acids had slightly less influence (80% and 78%, respectively). Exopolymers had the weakest effect on aggregation processes. Since exopolymers act as natural flocculants, their flocculating properties are highly dependent on the concentration, and at high concentrations they can stabilize colloidal particles.

How to cite: Kalinichenko, K., Oliinyk, V., Vorotytskyi, P., and Volobayev, I.: Impact of bionanocomposite on aggregation rate of soil colloids, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16418, https://doi.org/10.5194/egusphere-egu21-16418, 2021.

Discharge of organic dyes from different industries into receiving rivers and natural streams poses serious problems for the environment because of their toxicity. These dyes are not readily biodegradable and therefore, their removal from effluents is urgent. Various methods used for removal of dyes from wastewater, such as coagulation, flocculation, filtration or reverse osmosis are quite expensive and have a low removal efficiency. On the contrary, Advanced oxidation processes (AOPs) using metal oxide semiconductors like ZnO, are capable to operate effectively and efficiently to degrade many dye pollutants.

In this work, ZnO nanoparticles were successfully synthesized via a simple solvothermal method with different solvents. Scanning electron microscopy (SEM) imaging showed that nanoflower, nanorod, and nanosphere ZnO particles were produced when water, 1-hexanol, and ethylene glycol were used as the solvent, respectively. Nanoflower ZnO particles exhibited higher photocatalytic reduction efficiencies under UV light irradiation than nanosphere and nanorod particles. Results suggested a close relationship between the photocatalytic activity and the particle morphology and size which was due to using different solvents in preparation processes. Also, the recovery of ZnO nanoparticles was investigated and samples showed stable photodegradation efficiencies after being reused for three times.

How to cite: Amininejad, S., Baumann, T., Talebian, N., and Amininezhad, S. M.: Morphological effect of ZnO nanoparticles for photocatalytic degradation of azo dyes in water, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10339, https://doi.org/10.5194/egusphere-egu21-10339, 2021.

The released silver nanoparticles (AgNPs) will inevitably interact with suspended sediment (SS), because of the ubiquity and abundance of SS in aquatic systems. However, the effect mechanism of SS on the transformation of AgNPs remains unknown and unpredictable. This research investigated the effect of SS on the aggregation, settling, and dissolution of polyvinylpyrrolidone-coated (PVP) AgNPs under environmentally diverse salinity conditions. By determining the morphology of AgNP–SS heteroaggregates and using the DLVO analysis, we revealed that the heteroaggregation between AgNPs and SS was dependent on ionic strength. The formation of AgNP-SS heteroaggregates eventually lead to the rapid settling of AgNPs. Besides, the interactions of sediment-associated dissolved organic matter (SS-DOM) with AgNPs interfered the dissolution of AgNPs under different NaCl concentrations. The fate (i.e., aggregation, dissolution and settling) of AgNP in sediment-laden water has been found to be strongly dependent on the presence of SS, SS-DOM and ionic strength. This work provides novel insight into the interaction between suspended particulate matter and AgNPs as well as its effect on AgNP physicochemical transformation in aquatic environment.

How to cite: Zhao, J. and Li, Y.: Stability and dissolution of silver nanoparticles in sediment-laden water: Influence of suspended sediment and associated dissolved organic matter, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1945, https://doi.org/10.5194/egusphere-egu21-1945, 2021.

Rivers are often pictured as transport routes for plastics and microplastics from land to sea. Indeed, from a geological and geomorphological perspective, the main system function of rivers is the transport of water and sediments. An increasing amount of studies has detected microplastics not only in river waters but also in river sediments, banks and floodplains. The occurrence of microplastics in both aquatic and terrestrial systems raises the question of processes related to microplastics at the two system’s interface. However, in microplastics’ research, aquatic and terrestrial compartments are usually investigated separately from each other. Such a restricted perspective cannot explain reality adequately: Rivers are highly dynamic and complex systems, they are framed by and interact with terrestrial systems on different spatial and temporal scales. This interaction is known with regard to sediment deposition and erosion as well as pollutant or nutrient enrichment. In microplastics’ research, to date, little is known on interface processes such as (potentially bidirectional) horizontal and vertical plastic transport, deposition and erosion as well as remobilization. Little is known on the fate of plastics within both systems and at the interface: fragmentation, leaching and absorption of chemicals, biofilm formation, homoaggregation, heteroaggregation, intake by plant and animal organisms. However, a comprehensive understanding of sources, transport paths, as well as sinks is not only an academic problem but can support political stakeholders to manage pollution by microplastics. Therefore, we suggest to shed light not only on microplastics’ abundance in rivers or soils but also on processes at the interface of aquatic and terrestrial systems.

How to cite: Prume, J. and Weber, C.: Microplastics research at the interface of aquatic and terrestrial systems – Opinion, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-3074, https://doi.org/10.5194/egusphere-egu21-3074, 2021.

Plastics pollution of terrestrial environments is a global problem, and plastics have been observed even in remote areas. However, how much plastic is present in terrestrial ecosystems is not well known. Here, we present a theoretical framework for representative sampling of randomly distributed plastic particles in soils or sediments. Based on geostatistical analysis, we determined optimal sampling strategies to quantify micro- and nanoplastics in soils or sediments. We used numerical simulations to test the sampling of randomly distributed plastic particles, and determined the sampling support (number of cores or sampling area) needed to obtain plastic concentrations within a specific error. Plastic pollution in the field was numerically simulated by placing plastic particles randomly in two dimensional space. We then took soil samples with differently sized cores, and determined plastic concentration as a function of number of cores taken. We will show how many cores are needed to determine the plastic concentrations within a given error.

How to cite: Yu, Y. and Flury, M.: How Many Soil Samples Do We Need to Take to Determine Concentrations of Micro- and Nanoplastics in Terrestrial Systems?, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10420, https://doi.org/10.5194/egusphere-egu21-10420, 2021.

To assess microplastics abundance in the aquatic environment different filtering tools (nets, meshes and filters) are generally applied.  As a result, their naturally occurring size-frequency distributions are altered because of removing of items smaller than the mesh size. This hampers comparison of the results between studies utilized filters and nets of different mesh size. To assess the process of MPs generation and filtration, a stochastic model of macroplastic destruction coupled with the model of MPs filtration on the net was proposed. The stochastic model of macroplastic destruction incorporates empirical parameterizations of fracture position and fracture probability as a function of particle shape. The model sensitivity was tested in respect to the input parameters: the initial number of particles, the initial size of the macroparticles, the number of fracture steps (number of generations, i.e. the final ‘age’ of the particles), and the number of independent ‘sources’ in the final particle set.

The simulation results were compared with the available publications as well as with the data collected at Lake Onego. This allowed us to achieve qualitative agreement between the modelled and the observed distributions based on the similarity of the shape of size-frequency distribution curve in log-log scale.

Large particles, which have all three dimensions larger than the mesh size, are retained by the net efficiently. For others the probability of particle retention by the net depends on the particle shape, smallest and largest dimensions, and particle orientation in space.

To simulate the actual filtration process on the net, a mathematical model of filtration process was developed. The model passes a given set of three-dimensional particles (in quasi-elliptic approximation) through a two-dimensional net with a given cell size. Randomly given parameters determine the position of a particle in space, the size of its projection on the two-dimensional plane (net), and the position of the particle centre with respect to the corners of the cell (net). 

The results of plastic breaking simulation were coupled with a stochastic MP particle filtration model. This allowed us to show qualitatively how the shape of size-frequency distribution of MP particles is altered after the filtering through the net with a mesh size close to the lower boundary. This information can be used to compare the results obtained in studies utilized different neuston nets and filters, which is one of the most relevant tasks in the assessment of environmental contamination by microplastics on a global scale.

The study was supported by the Russian Science Foundation grant number 19-17-00035.

How to cite: Bagaev, A. and Zobkov, M.: Prediction of microplastics particles size-frequency distribution via the stochastic modelling of their formation and filtration on the net, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-7761, https://doi.org/10.5194/egusphere-egu21-7761, 2021.

The Rhine River flows through six European countries and is in exchange with diverse land use forms and human activities that potentially release microplastics (MPs). The Rhine interacts permanently with its surrounding banks and floodplains by changing water-levels. Several studies have documented the presence of MPs in the Rhine along its course as well as in its tributaries. However, the spatial distribution of MPs due to certain flood events in alluvial floodplains remains widely unclear. The knowledge about the amount and distribution of MPs and on their potential entry pathways into Rhine floodplains is essentially important for an ecological risk assessment. In this study, we analysed the amount and distribution of MPs in a floodplain soil in the nature reserve Merkenich-Langel, in the northern periphery of Cologne (Germany). We hypothesize that MPs are transported by the Rhine and are deposited at the site during flood events. For spatial analysis we used the MIKE software (DHI A/S, Hørsholm Denmark) merged with a digital terrain model of the study site to analyse past flood events and their potential deposition of MP. We chose three sampling transects located within the past flooded area each with three sampling spots with increasing distance and elevation to the river. Samples were taken from two different soil depths (0–5 cm and 5–20 cm) and the samples of the three sampling spots and same depth were combined to one mixed soil sample per transect. MP concentrations were analysed via ATR-FTIR and µ-FPA-FTIR spectroscopy after density separation and enzymatic-oxidative purification. We found an increase of MP concentration per kg of dry soil in the depth 5–20 cm with increasing distance to the river ranging from 25.612 particles/kg to 85.076 particles/kg. The results of MP concentration in 0–5 cm topsoil layer will be compared to the concentration in the soil depth of 5–20 cm. We correlate these results to the frequency of flood events.

How to cite: Rolf, M., Löder, M. G. J., Laermanns, H., Kienzler, L., Steininger, F., Möller, J., Laforsch, C., and Bogner, C.: Spatial analysis of riverine microplastic in a Rhine floodplain soil in Germany, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2383, https://doi.org/10.5194/egusphere-egu21-2383, 2021.

Agricultural soils play a key role as sink of microplastic (MP) coming from different sources, especially via the application of sewage sludge, compost, plastic mulch films, and tire ware. However, the effectiveness of this sink might be substantially reduced in areas subjected to water erosion. The aim of this study is to determine the transport behavior of MP during water erosion events on arable land. More specifically it is analyzed if MP is preferentially transported or behaves more conservative as attached to soil minerals and/or encapsulated in soil aggregates. A series of rainfall simulations were performed over 1.5 years on two plots at two test sites representing different intensively used soils (silty loam and loamy sand) in Southern Germany. The plots (4.5 m x 1.6 m) were spiked with microplastic (high density polyethylene) consisting of two different size fractions, fine MP (MP_f, 53-100 μm) and coarse MP (MP_c, 250-300 μm) incorporated into the topsoil (< 10 cm). The results clearly underline the selective nature of MP erosion leading to an enrichment ratio of MP in the eroded sediments of the loamy sand plot of 3.82 to 7.86, compared to an enrichment ratio from the silty loam plots of 1.41 to 5.29. Interestingly, there was no significant difference in enrichment ratios between MP_f and MP_c. Over time, an increasing connection between MP and soil particles could be observed. During the first rainfall simulation only 12% (MP_c) and 34-49% (MP_f) of the eroded plastic particles were connected to mineral particles or soil aggregates, while during the last simulation 1.5 years later about 31-47% (MP_c) and 57-67% (MP_f) of the eroded particles were bond to the soil matrix. Overall, our results indicate a strong dependency of the erosion transport behavior of MP depending on soil characteristics and time since application, while surprisingly we found little effect of MP size. 

How to cite: Rehm, R., Zeyer, T., and Fiener, P.: The transport of microplastic on agriculture soils via soil erosion, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-323, https://doi.org/10.5194/egusphere-egu21-323, 2021.

Accumulation of microplastics (MPs) in aquatic environments is an issue of emerging concern. After research initially focused on marine systems, more and more studies have been published investigating the abundance of MPs in freshwater environments in recent years.

The objective of our research is to examine, whether the Mulde river represents an input pathway for MP particles to the Elbe discharge system. Our hypothesis is that the chemical industries located in the catchment area of the Mulde act as a discharge source of primary MPs which are subsequently transported downstream towards the Elbe. Accordingly, there should be more (primary) MPs just downstream of the river mouth, compared to upstream. Therefore, 2 sediment samples and 18 water samples from the Elbe river upstream and downstream the Mulde confluence were taken and analysed on their MP contents.

To extract MPs, sample preparation requires various steps including drying, size-fractionation, reduction of organic matter and density separation. The gained fractions are then filtered through glass microfibres paper using a vacuum pump. The dried filters are photographed and examined for MPs under a digital microscope. Representative particles are picked and measured. Finally, we determine their polymer type by pyrolysis or µFTIR.

A key result is that both, sediment and water samples, show a substantial increase in primary MPs (especially spheres) just downstream the mouth of the Mulde. Regarding the sampling technique of water samples, we observe differences in the amount and shape of MP particles between filter cascades and filter nets.

How to cite: Kruse, J., Laermanns, H., Stock, F., Foeldi, C., Schaefer, D., Scherer, C., and Bogner, C.: Microplastic in fluvial environments - an example of the Elbe river near Dessau-Roßlau, Germany, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2686, https://doi.org/10.5194/egusphere-egu21-2686, 2021.

The wide utilization of plastic related products leads to the ubiquitous presence of plastic particles in natural environments. Plastic particles could interact with kaolinite (one type of typical clay particles abundant in environment) and form plastic-kaolinite heteroaggregates. The fate and transport of both plastic particles and kaolinite particles thus might be altered. The cotransport and deposition behaviors of micron-sized plastic particles (MPs) with different surface charge (both negative and positive surface charge) with kaolinite in porous media in both 5 and 25 mM NaCl solutions were investigated in present study. Both types of MPs (negatively charged carboxylate-modified MPs (CMPs) and positively charged amine-modified MPs (AMPs)) formed heteroaggregates with kaolinite particles under both solution conditions examined, however, CMPs and AMPs exhibited different cotransport behaviors with kaolinite. Specifically, the transport of both CMPs and kaolinite was increased under both ionic strength conditions when kaolinite and CMPs were copresent in suspensions. While, when kaolinite and positively charged AMPs were copresent in suspensions, negligible transport of both kaolinite and AMPs were observed under examined salt solution conditions. The competition deposition sites by kaolinite (the portion suspending in solution) with CMPs-kaolinite heteroaggregates led to the increased transport both CMPs and kaolinite when both types of colloids were copresent. In contrast, the formation of larger sized AMPs-kaolinite heteroaggregates with surface charge heterogeneity led to the negligible transport of both kaolinite and AMPs when they were copresent in suspensions. The results of this study show that when plastic particles and kaolinite particles are copresent in natural environments, their interaction with each other will affect their transport behaviors in porous media. The alteration in the transport of MPs or kaolinite (either increased or decreased transport) is highly correlated with the surface charge of MPs.

How to cite: Li, M., He, L., Zhang, X., Rong, H., and Tong, M.: Different Surface Charged Plastic Particles Have Different Cotransport Behaviors with Kaolinite Particles in Porous Media, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4766, https://doi.org/10.5194/egusphere-egu21-4766, 2021.

Contamination of the World Oceans with microplastics (MPs) is one of the most discussed environmental problems of the last decade. MPs are able to accumulate on their surface pollutants present in water in very low concentrations. Concentrations of pollutants, such as metals, can reach values that exceed the natural background in water bodies.Thus, MPs can act as a secondary source of contamination of water bodies with metals.The sorption capacity of artificially grinded and aged in the natural environment microparticles of polyethylene terephthalate (PET) with respect to metals in the natural water of Lake Onego was assessed in laboratory conditions.The Total Content method was used to characterize the sorption process and to obtain the dependence of the concentration of a substance in the stationary phase on its concentration in the mobile phase (experimental sorption isotherms were obtained). Subsequent mathematical processing of the experimentally obtained metal sorption isotherms on PET for Mn, Ni, Cu, Cd, and Pb allowed us to determine the monolayer capacities, adsorption equilibrium constants, and adsorption values at the equilibrium adsorbate concentration for each of the studied metals. This information is valuable to assess the role of MPs in metals transport in water bodies. The study was supported by the Russian Science Foundation grant number 19-17-00035.

How to cite: Kulik, N. and Efremenko, N.: Assessment of the sorption capacity of PET microparticles in natural water with respect to metals, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4438, https://doi.org/10.5194/egusphere-egu21-4438, 2021.

Although the impact of microplastic particles (MPs) in different ecosystems has recently become subject of numerous studies, the knowledge of spatial distribution and transport of MP in terrestrial environments is still limited. While first studies in this field have focused on the abundance of MPs in soils and its vertical distribution, only little is known about the mechanisms of MP transport on the surfaces of sediments and soils. To analyse the interaction between soil surface roughness, inclination and irrigation rate, we investigate MP surface transport mechanisms and patterns by using images of an advanced scientific complementary metal–oxide–semiconductor (sCMOS) high-resolution camera. For this study an experimental set-up including a flume box with several surfaces and an artificial irrigation system was used. In this setup we traced pathways of fluorescent amorphously shaped polystyrene (PS) and Polymethyl methacrylate (PMMA) particles on surfaces of different roughnesses and inclination. Subsequently, time series of the images were analyzed by combining R and Python packages was. This included the calculation of MP particle size, estimation of pathways and path lengths.  Our first results suggest a large influence of the water film thickness and the microrelief of the studied surfaces leading to the creation of preferential pathways for the MP particles.

How to cite: Laermanns, H., Haas, D., Klee, M., Steininger, F., Löder, M., and Bogner, C.: Method and challenges of tracing soil-surface transport of microplastic particles with an advanced-imaging sCMOS camera, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2033, https://doi.org/10.5194/egusphere-egu21-2033, 2021.