SSS7.5

There are a lot of materials, i.e. organic and inorganic wastes that can be use to improve soil properties, and also can be part of Anthrosols and Technosols, both defined in the World Reference Base for Soil Resources (2015) as soils with strong human influence. The first one, associated to intensive agriculture and comprise soils that have been modified profoundly through human activities, such as addition of organic or mineral material. The second one combine soils whose properties and pedogenesis are dominated by their technical origin. Technosols contain a significant amount of artefacts (something in the soil recognizably made or strongly altered by humans or extracted from greater depths) or are sealed by technic hard material (hard material created by humans, having properties unlike natural rock) or contain a geomembrane. The use of organic wastes to improve their properties or being part of the components forming a Technosol can increment the presence of trace elements which an alteration of their composition. These trace elements could suppose an environmental risk as a source of pollution affecting soil, water and biodiversity. The objective of this work was to determine the trace element composition of five organic wastes (pine bark, palm leaf, hay straw, almond pruning, pomegranate fruit skin) in order to know their composition and possible effects when they will be used for Technosol making or to improve soil properties. The composition of them varied. Five samples from each waste were digested by using H₂O₂+HNO₃ in microwave furnace and after that, elemental composition was measured by Inductively Coupled Plasma Optical Emission Spectroscopy. As, Cd, Co, Ni, Pb and V were under the limit of detection (we consider for all the elements a general limit of detection to compare all of them of 2 micrograms per litter; for this technique the limit varies from 0.03 to 1.5 micrograms per litter depending on the element). The elemental composition of the wastes showed that Ba, Cr, Cu, Li, Mn, Mo, Se and Zn were below 20 mg/kg dw in all of them. The rest of the elements presented concentrations over 20 mg/kg dw. In general, major differences were found in some trace and major elements: B and Ca in pine bark, K in pomegranate skin, Mg and Na in palm leaf and Sr in almond pruning. As a conclusion, the elemental composition of these wastes would be considered when a Technosol will be prepared including these materials or when they will be used as soil amendments.

How to cite: Navarro Pedreño, J., Rodríguez Espinosa, T., Gómez Lucas, I., Jordán Vidal, M. M., and Almendro Candel, M. B.: Trace elements of organic wastes with a potential use for improving soils, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1162, https://doi.org/10.5194/egusphere-egu21-1162, 2021.

In the past 150 years, sewage disposal onto agricultural land was a common practice around the world that resulted in accumulation of organic matter, salts, nutrients and heavy metals in the soils and the subsequent percolation into the groundwater. We present a study conducted on a former sewage farm in Germany, state of Brandenburg, were wastewater coming from Berlin was used for more than one century to irrigate the surrounding fields. In the area of a sewage sedimentation basin, 110 soil samples at the depth of 15-20 cm (waste layer) and 4 boreholes (10 samples up to 100 cm depth) were collected in order to determine pH, LOI and concentration of chosen metals. For the elemental analysis, two methods: X-ray fluorescence (XRF) and Atomic Emission Spectroscopy (MP-AES) were used. The analysis confirmed the presence of relatively homogenous sewage waste layer at the 20 cm depth, characterized by slightly acidic to neutral pH (6.3-7.5), high OM accumulation (up to 49%) and elevated concentrations of potentially toxic chosen metals (Cu, Ni, Pb, Cr and Zn). The correlation analysis performed by R software revealed strong between metal distribution and OM content. The XRF elemental analysis performed prior and after LOI, revealed metal concentration increase in mineral samples (up to 50% of the original value). An empirical correlation using a linear regression was found between OM content loss and metal concentration increase. Comparison of the AES and XRF elemental analysis of the mineral samples revealed significantly higher results for the X-ray fluorescence method, except for Cr. A correction factor, based on OM reduction, applied to the values, resulted in better correlation of XRF and AES results, questioning feasibility of this method for samples highly affected by sewage influence.

How to cite: Sut-Lohmann, M., Ramezany, S., Klos, F., and Raab, T.: Spatial and vertical determination of chosen potentially toxic metals and soil properties on a former sewage farm near Berlin, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4220, https://doi.org/10.5194/egusphere-egu21-4220, 2021.

We present a study conducted on a former sewage farm near Berlin, where long term sewage disposal onto agricultural land resulted in a high accumulation of potentially toxic metals. Based on a previous study, 30 samples collected within an area of a former sedimentation basin were selected (at the depth of 15-20 cm and one borehole up to 100 cm deep). The modified Tessier sequential extraction was applied in order to determine the partitioning of particulate potentially toxic metals (Cr, Cu, Ni, Pb, and Zn) into following fractions: 1) Exchangeable, 2) Bound to carbonate, 3) Bound to Fe/Mn oxides, 4) Bound to organic matter, and 5) Residual fraction. As a complementary analysis, diffuse reflectance infrared fourier transform spectroscopy (DRIFTS) technique was used for the interpretation purposes.

The obtained results demonstrated different metal speciation in the studied soil; Pb was mostly discovered in the residual fraction (77%) followed by Cr (53%), Cu (8%), and Zn (5%), while Ni was not extracted in this fraction. The organic matter-bound is the dominant species of Cu (77%). However, Zn and Ni exhibit the highest affinity for Fe/Mn oxides fraction (55% and 39%, respectively). The average mobility factor followed the order Ni > Zn > Cu whereas Cr and Pb were not found as exchangeable nor in carbonate forms. Study also revealed that DRIFTS is applicable to interpret the sequential metal extraction, especially for the carbonates-bound, organic matter-bound, and residual fractions. The spectral changes in organic and inorganic regions can indicate the soil components’ dissociation is proportional to the extraction.

How to cite: Ramezany, S., Sut-Lohmann, M., Klos, F., Bonhage, A., and Raab, T.: Using Modified Tessier Scheme to Metal Speciation in a Former Sewage Farm and interpretation of the sequential extraction by FTIR, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-6482, https://doi.org/10.5194/egusphere-egu21-6482, 2021.

The progressive increase of population living in cities led to the aggravation of the pollution problem worldwide, especially in urban environments. Air, water and soil are compartments affected by this reality, and the pollution leads to human health problems. There are many different point and non-point sources of emerging pollutants such as microplastics, which are transported diffusely through wind and rain. Therefore, it is very complex to quantify, control and treat these pollutants, designated current problematic issues by the European Commission. Green areas are pointed out by experts as natural filters for contaminants in cities, through their capacity of retention by leaves and soil.

This study investigates the contamination of microplastics in urban green areas soils, as well as the possible sources of microplastics, with a case-study in Coimbra (Portugal). Nine samples of fifty grams of soil were taken: three from a mixed broad-leaved with coniferous forest; three from a green park; three from a natural grassland. Six samples of three litres of water were taken from: rainwater (wet and dry deposition); runoff; freshwater; stream near the mixed forest; stream near the green park; stream near the natural grassland. All the samples were analysed in the laboratory through the extraction of microplastics using the flotation and filtration methods, and the visualization and identification of the particles with a microscope.

Microplastic particles were found in all samples. The number of microplastics found in soil samples varies between 2200 p kg^-1 and 190400 p kg^-1, both values obtained in a green urban park. Different levels of microplastics were found in the soil of the three sampled spaces with just a few meters of distance. Most of the particles (80%-98%) have less than half a millimetre. The water samples contained a lower number of microplastic particles. The values ranged from 27 p l^-1 in a peak flow stream near the natural grassland and 7 p l^-1 in freshwater from the tap. In rainwater were found 15 p l^-1 and in runoff 17 p l^-1 particles. Almost all microplastics particles (97%-100%) from water have less than half a millimetre.

Characteristics such as leaf area index, road proximity and intense precipitation episodes could influence the quantity of microplastics in the soil of green areas and in the streams and runoff. In order to control the entry and the concentration of microplastics in the environment and treat polluted areas, especially in cities, it is essential to quantify the microplastics particles considering the sources, pathways and the local characteristics of vegetation and soils.

How to cite: Amorim Leitão, I., van Schaik, L., Dinis Ferreira, A., and Geissen, V.: Microplastics occurrence in an urban space - Coimbra city case-study, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9680, https://doi.org/10.5194/egusphere-egu21-9680, 2021.

In order to obtain a more cost-time efficient way to predict the Exchangeable Sodium Percentage (ESP) function to Sodium Adsorption Ratio (SAR_e) of salt-affected soils in the High Valley of Cochabamba (Bolivia), two regression models were generated: ESP= 0.972 SAR_e + 1.576 (R²=0.85, P <  0.0005) and ESP= 6.522 SAR_e^0.5 – 5.723 (R²=0.78, P < 0.0005), based on 84 soil samples. The efficiency of the models was evaluated through an independent test set with 18 samples. The predicted ESP values showed a significant relationship with the measured ESP values: (R²=0.69, P < 0.0001) and (R²=0.68, P < 0.0001), respectively, and according to T-test of paired samples were not significantly different (P > 0.05).  Both models are relatively similar in terms of performance and could be recommended to predict ESP from SAR_e in the High Valley. To improve the prediction, additional samples for modelling and data stratification in terms of sodicity might be necessary.

How to cite: Andrade Foronda, D.: Estimation of the Exchangeable Sodium Percentage from the Sodium Adsorption Ratio for salt-affected soils in the High Valley (Bolivia), EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10271, https://doi.org/10.5194/egusphere-egu21-10271, 2021.

Consumption up to 95 % of the global freshwater resources for irresponsible outdated irrigation practice is no longer permissible worldwide. This huge water consumption is usually declared as an insurmountable consequence of irrigation technology and justified by the need for food production. This abnormal amount contradicts the task of human survival. Thus a call for a technological and regulatory breakthrough in the sphere of water resources is urgent. The current irrigation paradigm is based on imitation of natural rain, drip, surface or subsurface water flux to the soil. Old outdated irrigation paradigm links together two stages of the soil moisturizing process: water supply to the soil and water spreading throughout the soil continuum. This is a systemic disadvantage of standard irrigation. This lack stems from the simulation of natural water distribution.  The current imitative paradigm of irrigation simultaneously reproduces other phenomena of the natural hydrological process. These are excess of freshwater consumption for 4–15 times compared with plant water demand; spatial differentiation of the soil moisture and vegetation growth conditions; soil compaction and over-moistening and landscape waterlogging; increased share of the unstable mineral in soil, preferential water fluxes through the soil to vadose zone and saturation zone; leaching of the soil organic matter and nutrients, and generally uncontrolled biogeochemical process caused by the standard irrigation.  

We developed the transcendental Biogeosystem Technique (BGT*) methodology as a basis of development of the new soil watering paradigm. New intra-soil pulse continuous-discrete plant watering paradigm is executed by injection of successive small portions of water intra-soil via syringe into the soil vertical cylinder of 1.5–2.5 cm diameter at a depth of 10 to 35 cm. In the period of 5–10 min after individual injection, the water redistributes in the soil in the vicinity of the watered cylinder via capillary, film and vapour transfer. An ambient soil carcass remains mechanically stable. This carcass supports the soil which was disturbed hydrodynamically while intra-soil water injection mechanically, providing a multilevel aggregation of the soil fine fractions preferable for development of the rhizosphere. Resulting matrix soil water potential is of −0.2 MPa. At this potential, the soil solution has a rather high concentration. This concentration is optimal for the nutrition of plants. At the same time, such concentration of the soil solution is healthy for the soil, soil biota, and plant as a rather high air content provided. In absence of the over-moistening, the plant resistivity for pathogens becomes higher. The stomatal apparatus of plants operate in regulation mode, providing water saving. Freshwater consumption 4–20 times less compared to standard irrigation. Fertilizers, pesticide efficiency, and soil productivity are higher. Higher rate biogeochemical process control is provided. The environmental damage of standard irrigation excluded. BGT* robotic intra-soil pulse continuous-discrete watering system developed. The opportunity provided for the global water scarcity overcoming. It is possible to expand the biosphere and provide non-conflicting sustainable technological and environmental safety.

The research was supported by the RFBR, project no. 18-29-25071, and the Ministry of Science and Higher Education of Russia, no. 0852-2020-0029.

How to cite: Severina, V., Proklin, V., Rykhlik, A., Kalinitchenko, V., Glinushkin, A., Dubenok, N., Minkina, T., Nesvat, A., Deryabkina, I., and Zamulina, I.: Biogeosystem technique water paradigm for prevention of the world water scarcity and cardinal transformation of current irrigation practice, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14922, https://doi.org/10.5194/egusphere-egu21-14922, 2021.

Zinc based nanoparticles (NPs) have a great importance among the metal-based NPs and widely produced after SiO₂ and TiO₂. The rapid growth of ZnO NPs production and its abundant uses in many industries, and increasing release into an environment from both intentional and unintentional sources, create risks to human health. The recent finding of ZnO NPs application indicates positive and negative effects on plant growth. However, studies exploring the effect of ZnO NPs on the internal organelles of plants and their correlation with the function of photosynthesis are a few. The spring barley (Hordeum sativum L.) is one of the most important staples food crop and is identified as an efficient potentially toxic elements accumulator with phytoremediation potential. Thereby, the present work aimed to investigate the toxic effects of ZnO NPs on physiological and anatomical indices of H. sativum growth grown in a hydroponic condition as it allows to simplify model, where the parameters of plant growth can be easily controlled. Thus, the commercial-grade ZnO NPs (particle size 30-50 nm) was used with the scheme; control (0 ppm), low (300 ppm ZnO NPs), and high (2000 ppm ZnO NPs) the dose of NPs. The low and high levels of ZnO NPs were selected with consideration for the existing levels of Zn in the polluted soils. The results showed ZnO NPs affected the photosynthetic efficiency of H. sativum plants by affecting chlorophyll fluorescence emission, deformation in stomatal and trichomes morphology, damaged cellular organizations, i.e., irregularities in chloroplasts, disruption in grana and thylakoid organizations. Cytomorphometric quantification revealed that ZnO NPs decreased chloroplasts size 4 times in 2000 ppm and 1.5 times in 300 ppm ZnO NPs treated plants. The lower number of chloroplasts per cell were observed in ZnO NPs treated H. sativum leaf cells. The destructive methods of Zn elemental analysis showed 10.2 folds and 3.8 folds higher accumulation in 2000 ppm and 300 ppm ZnO NPs treated leaves than the control, respectively. Additionally, the presence of Zn content in H. sativum leaf tissue was also confirmed by the X-ray fluorescence spectroscopy elemental analysis. The high contents of Zn were visible in several spots in ZnO NPs treated leaf tissues. The accumulation of Zn content dissolute from ZnO NPs damaged the structural organization of the photosynthetic apparatus and reduced the photosynthetic activities. The modifications in anatomical indices were significantly correlated with physiological observations. The work presented here will help to increase the scientific understanding of the toxicity of ZnO NPs in plants and will widen the scope to tailor the nanomaterials to improve the effectiveness, smart and targeted delivery to avoid damages of most significant tissues of plants.  

This study was funded by the RFBR, project nos. 19-34-60041 and 18-29-25071, and the Ministry of Science and Higher Education of Russia, project no. 0852-2020-0029.

How to cite: Beschetnikov, V., Rajput, V., Minkina, T., Fedorenko, A., Bauer, T., Chernikova, N., Glinushkin, A., Kalinichenko, V., Hassan, T., Sushkova, S., Soldatov, M., Lysenko, V., and Azarov, A.: Effects of zinc oxide nanoparticles on physiological and anatomical indices of Hordeum sativum L. growth, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-14153, https://doi.org/10.5194/egusphere-egu21-14153, 2021.

Coal mining and burning are major anthropogenic sources of atmospheric particles and heavy metals (HMs) (Wang et al., 2011).Coal dust contains a wide range of metal including Ni and Cd. Sequential extractions are the most used methods to estimate the mobility of metals closely related to bioavailability. The classic sequential extraction methods by Tessier (Tessier et al., 1979) are the most popular method of HMs. The aim of this work was to study the speciation of Ni and Cd in soils under anthropogenic contamination with combustion products from the Novocherkassk power plant (NPP).

The monitoring plots were arranged along predominant wind direction at 1.6 and 15 km from the emission source. The studied soils are represented by Haplic Chernozem. The properties of the soil were: pH - 7.3-7.4; 28.6-30.9% of silt, the content of organic carbon is 3.0-3.7%; carbonates - 0.3%; content of nonsilicate Fe – 3.8-3.9%; CEC – 35-37 cmol kg^–1. Areas located within 4 km from the power plants are subjected to the highest ecological disturbances; and a zone almost free from contamination is located beyond 15 km (Minkina et al., 2013).

It was found that the total content of Ni (39.0 mg kg^–1) and Cd (0.1 mg kg^–1) in the unpolluted soil far away from NPP (at 15 km) matching the background metal content in Haplic Chernozem was almost four times lower (145 mg kg^–1 and 3.8 mg kg^–1 accordingly) than in the soil located under the influence of aerosol emissions (at 1.6 km). In an uncontaminated soil occurring far from the emission source, 62–64% of total Ni and Cd fractions are concentrated in the residual fraction characterizing the metal bond with silicates. The following distribution of Ni among the fractions in the uncontaminated soil is noted: residual fraction > bound to organic matter > bound to Fe-Mn oxides > bound to carbonates > exchangeable. In uncontaminated soil, the following fractional distribution of Cd is observed: residual fraction> bound to Fe-Mn oxides > bound to organic matter > bound to carbonates > exchangeable.

Metals accumulate in the soil occurring near the power plant (at 1.6 km), which increases the total contents of Ni and Cd and their mobile (exchangeable and carbonate-bound) compounds in 18 and 33 times accordingly. With increasing pollution, the share of the residual fraction decreases (up to 42-47%) and the amount of the most mobile HM compounds increases. The high mobility in soils is established for Cd (exchangeable fraction was 9%). An increase in the Ni and Cd content in the soil increases its adsorption on the surface of Fe oxides (up to 20% and 27% accordingly). The role of soil organic matter in the absorption of Ni (up to 15%) is also noticeable.

Thus, the largest contributions to the adsorption and retention of metals are made by silicates, as well as nonsilicate Fe compounds for Cd and soil organic matter and nonsilicate Fe for Ni.

This work was supported by the Russian Science Foundation, project no. 19-74-00085

How to cite: Fedorenko, E., Burachevskaya, M., Severina, V., Barakhov, A., Tsitsuashvili, V., Minkina, T., and Savin, I.: Nickel and cadmium speciation in soils under long-term aerosol pollution, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-11836, https://doi.org/10.5194/egusphere-egu21-11836, 2021.

Soil organic matter biodegradation is an agent of the soil fertility and passivation of the hazardous substances including heavy metals. Bacteria within specific habitats, be it the mouth, tonsils, intestines, gut, vagina, or soil are not a faceless mixture of the once acquired participants, but the structurally strictly ordered polymicrobial communities where each participant takes its specific functional place. The conditions for polymicrobial biofilms in the soil are important.

The aim was tracking down the structural organization and adherence to soil particles of the polymicrobial communities and biofilms, responsible for biodegradation.  Polymicrobial communities and biofilms can be used as a starter, indicator, and control tools for the targeted soil and landscape improvements. Multiple skills in identification, characterizing and monitoring of functional activity of polymicrobial biofilms in the human body and gut were developed in the laboratory of polymicrobial infections and biofilms of the Charité hospital over the past 30 years. The biofilms do not occur in all systems and at any time in relevant amounts. The biochemical activity of the microorganisms till now is investigated solely in pure cultures. As soon as more than three different taxa are involved, the cultivation of the target microorganisms got problematic. The mapping of biofilms by the FISH method is promising for the following objectives in the soil system:

- identification of the structured polymicrobial biofilms for optimal composting, soil fertility, and a healthy environment;

- revealing modelling the polymicrobial starter of soil fertility;

- polymicrobial biofilms activity ensuring via control of the soil architecture, soil moisture and aeration;

- aerobe/anaerobe conditioning, pH, humic acids, and organic and mineral fertilizers, amelioration and remediation additives;

- testing of the substrate-bound polymicrobial biofilms as a starter for the shaping of different lands and agricultures.

Development of the soil-microbiological theoretical and technical fundamentals for the long-term soil improvement and environmentally safe organic wastes recycling and heavy metal passivation into the synthesized soil multilevel aggregate system under minimal intra-soil moistening and appropriate intra-soil mineral and organic matter, and waste application using Biogeosystem Technique (BGT*) transcendental environmental services.

The soil-microbiological theoretical and technical fundamentals are useful for long-term soil improvement and environmentally safe and eсonomically efficient organic wastes recycling into the synthesized soil aggregate system. The transcendental intra-soil aggregate system construction, the pulse intra-soil continuously-discrete watering, dispersed intra-soil matter application are decisive for higher soil microbial activity and target polymicrobial infections and biofilms transformation into the environmentally safe fertile substances.

Comparative characterization of the polymicrobial community dynamics in colon and soils will help to promote the function of polymicrobial biofilms in the soil as a specific starter. The BGT* methodology is capable to ensure the soil fertility, improve the soil polymicrobial biofilms resistance, and provide the soil and human health.

The research was financially supported by the RFBR, projects no. 18-29-25071 and 19-29-05265.

How to cite: Aysuvakova, T., Glinushkin, A., Swidsinski, A., Kalinichenko, V., Zavalin, A., Minkina, T., Sushkova, S., Mandzieva, S., Mukovoz, P., Chernenko, V., and Tatiana, M.: Soil polymicrobial biofilms resistance increasing using Biogeosystem Technique transcendental environmental services, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10974, https://doi.org/10.5194/egusphere-egu21-10974, 2021.

Soil contamination by heavy metals causes metal accumulation by plants, which leads to the degradation of plants communities and migration of toxicants with food chains to man. Therefore, the investigation of heavy metal concentration in soils of urban areas is an urgent scientific task. This study aims to examine the translocation of heavy metals from urban soils to herbs in Tyumen (Russian Federation).  Soil surface layer was collected at control site, near the highway as well as from areas with metallurgical, motor building, oil refinery and battery manufactory plants in Tyumen. Meadow grass, red clover, wild vetch, chamomile and coltsfoot were collected at all examined sites.  The mobile and acid-soluble heavy metal fractions in soils, as well as the heavy metal contents in plants, were determined by atomic absorption spectrophotometry. The bioconcentration factor was estimated as the ratio of the amount of heavy metals in soils to that in plants. The study was performed during three-year period from 2017 to 2019. Heavy metal concentrations in urban soils were higher than those at the control site by 20% and by up to 10 times. The greatest heavy metal accumulation in both soils and plants was found at the battery manufacturing and metallurgical plants, exceeding the control levels of Pb and Fe by 2-17 times. The Cu, Fe and Mn contents in soil were positively correlated with those in plants. Heavy metal translocation by the plants was species-specific. The percentages of the mobile heavy metal fractions decreased in the following order: Mn>Zn>Cu>Fe. Heavy metal accumulation in plants in the urban sites compared to that at the control site decreased in the following order: Fe>Zn>Cu>Mn>Pb>Cd. Coltsfoot exhibited the highest Fe, Mn, and Zn accumulation, which exceeded the control levels by 17, 5, and 3.5 times, respectively. The heavy metal bioconcentration factors, indicators of translocation, decreased in the following order: Cu>Zn>Cd>Pb>Mn>Fe. The heavy metal translocation suggests the need to relocate industrial facilities to outside the city. Future monitoring of the study area is needed to ensure its long-term ecological safety.

How to cite: Petukhov, A., Kremleva, T., and Petukhova, G.: Heavy metal translocation in soil-plant system in conditions of urban anthropogenic pollution (Tyumen, Russian Federation), EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-364, https://doi.org/10.5194/egusphere-egu21-364, 2021.

In recent years, exposure to volatile chemical substances (VCSs) from contaminated soil has become a serious problem so it has become increasingly important to study the transport phenomena of VCSs. In this study we focused on the transport phenomena of VCSs at the boundary layer between the soil surface and the atmosphere, and defined it as volatilization flux, which express the amount of volatilized substances per unit volume per unit time. In order to estimate the phenomena of mercury transport in unsaturated soil and mercury released from soil to the atmosphere, it is necessary to consider in detail the spatiotemporal fluctuations of factors that affect the volatilization of mercury and the physical transport phenomena in soil.

The present study developed a model for predicting the volatilization flux from the unsaturated soil contaminated by VCSs. The model considers a series of phenomena under the unsaturated condition such as gas-liquid two-phase flow consisting of convection and diffusion. The effects of various transport phenomena on the surface soil on changes in the magnitude of this flux due to variations in meteorological factors such as temperature and soil moisture content were quantitatively evaluated. This developed prediction model can be utilized to estimate dynamic variations in the flux under real-environmental conditions.

How to cite: Kondo, M., Sakamoto, Y., Komai, T., Kawabe, Y., Nakamura, K., and Watanabe, N.: Development of a numerical model for predicting the volatilization flux from unsaturated soil, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10449, https://doi.org/10.5194/egusphere-egu21-10449, 2021.

The inadequate treatment of waste materials in mine tailings, the closure stage not carried out correctly, carries risks due to the residues of potentially toxic elements (PTEs) that it may contain. In Panama, environmental regulations are recent, and even so the regulations are not strictly enforced, leaving a problem for the adjacent communities. Such is the case of the Remance Gold Mine, in Veraguas, Panama; this area has been exploited intermittently for over a hundred years, by different companies; the last period of exploitation was between 1989 and 1999, through a cyanidation process to extract the precious metal. Currently three tailing dams with mining waste are exposed to climatic conditions such as rain and wind, in addition to this, within the mine area and its surroundings live peasants who carry out subsistence activities such as agriculture and livestock. The purpose of this study was to evaluate the remaining potentially toxic elements and the persistence of cyanide in the tailings, and whether the remaining quantity represents a risk to human health and the environment, according to current environmental regulations in Panama and America. For this purpose, samples have been taken from the tailings and adjacent areas that could be directly related to the cyanidation process, geochemical analysis such as pH, CEC, conductivity, organic matter, potentially toxic elements and total cyanide have been carried out. The most concerning aspects of the results obtained here have been the contents of Ba (between 55 and 610 mg kg^-1), Zn (between 12 and 153 mg kg^-1), Sb (between 0.6 and 25.5 mg kg^-1) and Hg (between 0.1 and 3.2 mg kg^-1), which, according to the criteria of land use quality standards in Panama and American countries, correspond to values above the permissible limits for agricultural and residential land use. Meanwhile the levels of As (between 17.3 and 5030 mg kg^-1) and Cu (between 5.4 and 403 mg kg^-1) are higher than the legally established values for industrial land use. Far more significant are the values for total cyanide (between 1.4 and 518 mg kg^-1), revealing the persistence of this chemical over time. These cyanide values are far higher than those reported in the literature for solid tailings from an abandoned gold mine and the values for gold mine tailings in the Americas, thus representing a serious threat to the environment.

How to cite: González Valoys, A. C., Monteza-Destro, T., Esbrí, J. M., Vargas-Lombardo, M., Garcia-Ordiales, E., Arrocha, J., Jiménez-Ballesta, R., Garcia-Navarro, F. J., and Higueras, P.: Risks associated with the presence of cyanide in waste materials in an abandoned gold mine, Panama, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8236, https://doi.org/10.5194/egusphere-egu21-8236, 2021.

Castilla-La Mancha (CLM), located in South-Central Spain, is a region of some 80,000 Km² centered in agricultural and livestock activity, being the first major producer of wine and second of olive oil in Spain (after Andalucía), and an important producer of sheep cheese and lamb meal. Besides, the region has supported an important metallic mining activity, including mercury and base metals; these mines, most of them located in the West of the region, are actually closed, but still an important number of industrial minerals (limestone and gypsum as most important, but also other salts and clays varieties) are active in the central and Eastern part of the region.

Up to date, CLM does not have generic reference levels (GRLs) for elemental concentrations; neither it has a distribution map of potentially toxic elements (PTEs) along its territory. These are actually basic needs for regions with economy based on agriculture and livestock.

The project BiGeoQCLM, funded by Consejería de Educación, Cultura y Deportes, Regional Government of CLM, is aimed to obtain a portrait of the distribution of elements in the whole region; the information to collect is aimed to three main objectives: (1): characterize the elemental distribution, including the estimation of GRLs, and the delimitation of the distribution of elements, and in particular of PTEs in the mining areas; together with this, the characterization of the soils of the region, including the distribution of their pedological parameters (2): characterize the soil-to-organisms interactions, including microbiology (through enzymatic activity) and plants (through characterization of elemental plant uptake; and (3): the characterization of the elemental uptake by plants aimed to assess the origin of wine, including the isotopic footprint of soils and wines with certified origin.

The project is in its second year (of three) of development and the work in activity is still mostly related with the field and laboratory work. However, some results are available, and are being presented in other communications of this Conference. In particular, the activity in the South-West of the region, which was the richest in metals-based mining, has been boosted with the starting of the AUREOLE project, funded by European ERA-MIN program, and aimed to find new criteria for the research of Sb and related elements, as well as with the environmental concerns related with the mining of such elements.

This study is being funded by Consejería de Educación, Cultura y Deportes, JCCM (SBPLY/17/180501/000273), with the additional support of project PCI2019-103779, Spanish Ministry of Science and Innovation.

How to cite: Higueras, P., Garcia-Navarro, F.-J., Moreno-Valencia, M.-M., Esbrí, J.-M., Garcia-Pradas, J., González-Mora, S., Peco, J.-D., Ortega, C., Rivera, S., Amorós, J.-A., Lorenzo, S., Pérez-de-los-Reyes, C., Bravo, S., Villena, J., Campos-Gallego, J.-A., Moreno, C., García-Noguero, E.-M., Atance, C., and Fabeiro, C.: Biogeochemistry in Castilla-La Mancha region: concerns on mining/agriculture relationship., EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2561, https://doi.org/10.5194/egusphere-egu21-2561, 2021.

 “Rambla”are temporary watercourses, which are characteristic of mediterranean and semi-arid climates, with low rainfall and sporadic torrential rain. A few times a year, when the rainfall exceeds 80 mm in less than an hour, they are capable of evacuating high flows of water mixed with particulate material of different granulometries to the sea.

The Sierra Minera of Cartagena (Murcia, Spain) has two marine slopes, one of short distance and steep slope towards the Mediterranean Sea, and another of a greater extent that affects the Mar Menor, a specially protected saltwater lagoon.

The processes that can take place in the course of the ramblas that begin in the Sierra Minera, when water is present, are those of transport of particulate and soluble material, processes of dissolution, hydrolysis, redox, complexation, carbonation and precipitation among others. When the rainy season ends and the Surface water disappears, the sediments that have been left in the riverbed are subject to other secondary processes that lead to the formation of very particular mineralogical species, efflorescence of hydrated sulphates, carbonates and oxydroxides. This is due to the pore water which can remain for a long period of time in the sediments of the rambla bed. Depending on the degree of influence of the current mining sediments in the rambla, the water it transports can have an acid pH (3.5-5.5), being qualified as acid mine drainage.

The Rambla del Beal is one of the various watercourses that cross the Sierra and flow into the Mar Menor next to a wetland that is an Special Protection Area (SPA), which makes the study more interesting. Like other ramblas in the area, during different periods, it carried the waste from the mineral floatation plants to the sea, as if it were a natural pipe, so along its route there are abundant terraces formed by this waste. This is in addition to the materials dumped and the materials eroded from the ponds and dumps that are in its receiving basin.

A selective sampling has been carried out along the riverbed to its mouth, analysing the content of potential toxic elements (PTEs), granulometry, general characteristics and mineralogy.

The bioavailability and mobility of the different PTEs (As, Pb, Zn, Cd and Fe) and their relationship with the mineralogy have also been studied.

The results show that only in the central part of the rambla can sediments not affected by primary pollution be found (they are secondary pollution), and that the Rambla del Beal itself can be considered a focus or primary source of pollution by PTEs.

How to cite: Pérez-Sirvent, C., Martínez Sánchez, M. J., Martínez López, S., Martínez Martínez, L. B., Hernández Pérez, C., García Lorenzo, M. L., Hernández-Córdoba, M., Rodríguez Pedrosa, M. T., Ros Castejón, R., Valero Espín, E., and Bech, J.: Are “ramblas” the sewerage of metal pollution in mining areas with a semi-arid climate?, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10408, https://doi.org/10.5194/egusphere-egu21-10408, 2021.

Spatial distribution of As in a surface soil layer was determined in three historical mining sites in the Sudetes where As ores were exploited and processed over the centuries: in Złoty Stok (formerly: Reichenstein), Radzimowice (Altes Berg) and Czarnów (Evelinensgluck). Of those sites, Złoty Stok that operated until 1962, is the largest one. Thirteen patches of land situated in all those sites (6, 4, and 3, respectively) were chosen for analysis, each with an area of 2-5 hectares. They differed in terms of sources of soil enrichment in As, land topography and various types of land use or habitats. Both soils that developed on waste rock dumps and tailings, as well as those in their surroundings were examined. Simplified maps of As concentrations in soils were drawn based on 15-20 screening points located in each area. Arsenic distribution in soils in a mini-scale was examined by collecting multiple samples from several spots (each with an area of 1-10 m²). Gangue rock material disposed on the dumps was highly heterogeneous and locally contained over 1% of As. Total As concentrations in soil samples varied in a broad range: 72–193000 mg/kg, and the highest local enrichment in As was identified in alluvial soils along a stream affected by acid mine drainage. Various factors responsible for As concentrations in soils, including the amounts inherited from the parent rocks as well as various processes of redistribution, transport and secondary enrichment were discusses. Related environmental risk associated with a likely processes of further As mobilization and transport has been assessed with considering various scenarios. Additionally, soil enrichment and contamination indices, commonly used in the literature, such as geoaccumulation index Igeo, enrichment factor EF according to Sutherland and Nemerow pollution index PI, were calculated for each of the areas under study. Their ambiguity and limited suitability for the assessment of soil contamination with As were critically discussed.   

This research was funded by the National Science Centre of Poland; Project No. 2016/21/B/ST10/02221

How to cite: Karczewska, A., Szopka, K., Dradrach, A., and Gałka, B.: Spatial distribution of soil enrichment in As in the vicinities of historical mines – a case study of mining sites in the Sudetes, SW Poland, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-6631, https://doi.org/10.5194/egusphere-egu21-6631, 2021.

Soil contamination by heavy metals (HMs) is a worldwide problem for human health. Unlike organic pollutants which can be destroyed, HMs are non-degradable by chemical and microbial decomposition, and they are persistent and hard to remove once released into soils. Therefore, remediation of HM contaminated soils is exigent and imperative. One cost-effective and environmental friendly remediation approach is the application of biochar, which is a solid carbonaceous material. Biochar has been widely documented to effectively immobilize metals in contaminated soils and has received increasing attention for use in soil remediation. The purpose of the study is to analyze the efficiency of biochar for copper immobilization in contaminated soil using a combined fractionation scheme (Minkina et al., 2013), which makes possible to determine the composition of loosely (LB) and strongly bound (SB) HM compounds. This scheme is based on a combination of the results obtained by the Tessier method (Tessier et al., 1979) and parallel extractions (Minkina et al., 2018). The studies were carried out as a model experiment on Calcaric Fluvisol (Loamic) (at the depth 0-20 cm) collected in the Severnyi Donets River floodplain (Rostov region, Russia). The analyzed soil is characterized by following physical and chemical properties: C_org – 4.3%; pH 7.5; exchangeable cations (Ca²⁺+Mg²⁺) – 38.1 cMс/kg; CаCO₃ – 0.6%; content of physical clay (particle <0.001 mm) – 55.8%, silt – 32.0%, Cu – 43.7 mg/kg. In a model experiment the soil samples were artificially contaminated with higher portion of CuO (1320 mg/kg). The metal was incubated in soil samples for 6 months. After incubation of soil with metal, biochar was introduced into the vessels in the dose 2.5%. Biochar for the experiment was produced by pyrolysis (temperature 550°C) of birch wood. The elemental analysis, BET, SEM, FTIR, XRD and TGA were used to characterize the physicochemical properties of carbonized material. The domination of strongly bound Cu compounds (92% of total fractions), which is mainly supported of metal retention by primary and secondary minerals (66 %) was observed in uncontaminated soil (control). Mobility of Cu in soils was low (8%) and represented mainly by specifically adsorbed metal compounds. The content of all forms of Cu increases with artificial soil contamination and their ratio increases (up to 38%) in the content of LB compounds. The majority of residual fraction remains in the composition of SB of Cu compounds, however its relative content decreases until 41 % under anthropogenic load. The introduction of biochar has a significant effect on the transformation of Cu compounds in soil and it decreased the metal mobility due to formation of SB compounds. The relative content of LB metal compounds after use of biochar is almost equal to control variant with simultaneous redistribution of fractional-group composition of metal. Thus, the present study demonstrates the possible remediation of soil contaminated by HMs using biochar and provides a particular strategy for remediation of soils contaminated with Cu.

The reported study was funded by RFBR, project number 19-34-60041.

How to cite: Bauer, T., Minkina, T., Burachevskaya, M., Fedorenko, A., Lobzenko, I., and Fedorenko, G.: Cost-effective and environmental friendly remediation of heavy metal contaminated soils, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10842, https://doi.org/10.5194/egusphere-egu21-10842, 2021.

Agricultural soils in mining areas usually accumulate potentially toxic elements (PTEs) that can become a health risk to humans by entering the trophic chain. In this study, five small agricultural plots close to Riotinto mines (SW Spain) were studied, with the aims of comparing the concentration of PTEs with respect to the regional (South Portuguese Zone) baseline and conducting availability studies in order to determine the contamination of soils. Chemical composition, total and clay mineralogy, and edaphic parameters were determined in topsoil and subsoil samples to characterize the soils, and single extractions were conducted to assess the mobility. The mineralogy of the soils was composed of quartz and phyllosilicates, with small amounts of feldspars and occasionally containing hematite and calcite. The texture ranged from sandy to silty loam, the pH was slightly acidic, and high contents of organic matter were found. Total concentrations of trace elements correlated with the texture, the content in iron oxy-hydroxides and the pH. The values of As, Pb, Cu, and Zn exceeded the regional baseline even in sites unaffected by mining. The results suggest that a widespread sampling is necessary to determine the local background. The most water-soluble element was As, due to the competition of organic matter for sorption sites. The content of Cu, Cr and Zn extracted with different methods were higher in sandy soils with low iron oxy-hydroxides content. Monoammonium phosphate and EDTA extractions seemed to remove elements from organic matter and iron oxy-hydroxides. The extracted fractions of As and metals reached up to 10-30 wt%.  Despite the high total concentrations of the element in soils, they generally showed low available proportions, especially with water and ammonium acetate extractants. The results suggest that the soils are not necessarily a risk to humans and higher investigation efforts are necessary to assess the availability of PTEs and their transfer to plants.

How to cite: Romero-Baena, A., Barba-Brioso, C., Ross, A., and González, I.: Mobility of potentially toxic elements in family garden soils of the Riotinto mining area, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4197, https://doi.org/10.5194/egusphere-egu21-4197, 2021.

The concentrations of 16 priority polycyclic aromatic hydrocarbons (PAHs) in soils, under- and above-ground tissues of reed (Phragmites australis) on monitoring plots in the zone of industrial sewage tanks and sludge reservoirs in the city of Kamensk-Shakhtinskyi (southern Russia, Rostov Region), were determined. The total PAHs concentration in soil of monitoring site D3 (4229.4 ± 5.7µg kg^-1) was significantly higher than those in monitoring sites: D4 (3873.7 ± 17.1 µg kg^-1), TR1 (2217.3 ± 9.1µg kg^-1), 43 (2001.1 ± 13.0µg kg^-1), and also D0 (140.4 ± 1.0µg kg^-1) plots. Accordingly, the maximum accumulation was found for phenanthrene among the 16 priority PAHs in the most of the soil and plants samples. It was determined the PAHs pollution effect in the studied monitoring sites on cellular and sub-cellular organelles changes of P. australis. The data received shows that increasing of PAHs contamination negatively affected on the cellular and sub-cellular organelles changes of the studied pants. Using of electron-microscopic method for plants sub-cellular structure showed ultrastructural changes in the cell membranes, and the main cytoplasmic organelles of plant cells. It was established the P. australis had a high level of adaptation to the effect of stressors by using of tissue and cell levels. In general, the detected sub-cellular alterations under the PAHs effect were possibly connected to changes in biochemical and histochemical parameters as a response for reactive oxygen species and also as a protective response against oxidative stress. The results received carry in innovative findings for cellular and sub-cellular changes in plants exposed to 16 priority PAHs as very persistent and toxic contaminants.

The research was financially supported by the Russian Science Foundation project no. 19-74-10046.

How to cite: Barbashev, A., Batukaev, A., Sushkova, S., Minkina, T., Tarigholizadeh, S., Kalinitchenko, V., Glinushkin, A., Antonenko, E., Dudnikova, T., Chernikova, N., Fedorenko, A., Tihonenko, E., Deryabkina, I., Shportun, I., and Yakovlenko, A.: PAHs accumulation in soil-plant system in Atamanskoe lake bottom sediments in the long-term chemical contamination effect, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12739, https://doi.org/10.5194/egusphere-egu21-12739, 2021.

The use of phytostabilizing plants in remediation projects of areas affected by mining activities is one of the valid strategies for recovering the ecosystem.  It is often used to obtain biodiversity with the aim of restoring the environment, but the possible risk represented by the ingestion of the plants by the fauna and the consequent passage of As to the trophic chain is forgotten.

The aim of this study is to evaluate the environmental risk posed by arsenic when revegetation occurs in an area with high levels of this element. To this end, the transfer of arsenic in different plant species that grow spontaneously in an abandoned mining area (Sierra Minera de Cartagena) is analysed, as well as the contribution of these plants to the intake of mammals in the area. In order to make a comparison with the risk analysis applied to human intake, the wild boar is selected since this mammal has a digestive physiology very similar to that of humans. For this purpose, a gastric solution is prepared according to the standard operating procedure (SOP) developed by the Solubility/ Bioavailability Research Consortium (SBRC). Two phases, namely, stomach (AsA) and intestinal (AsN), are considered.

In this way, it is possible to discriminate between plant species with high, non-bioaccessible contents in the aerial part and plant species with the opposite.

For this study, 21 plant species that grow naturally in the soils of the Sierra Minera and their corresponding rhizospheres were collected.

The physical-chemical properties were obtained using the usual procedures. To determine the arsenic content, the soil samples and plant materials were digested in a microwave system and the arsenic concentration was determined using atomic fluorescence spectrometry with an automated continuous flow hydride generation system. Soils are classified into three groups: Low (group 1) (7-35 mg/kg), medium (group 2) (35-327 mg/kg) and high (group 3) (> 327 mg/kg), according to their As content. The descriptive statistical analysis of the population of plants studied shows that the range of As in the roots were from 0.31 to 150 mg/kg, while the concentrations in the leaves were lower (0.21 to 83.4 mg/kg). The possible risk of As entering the food chain through plant species is evaluated. The route of exposure considered is the oral ingestion, calculating the contribution of the plant to the daily dose based on the concentration of arsenic (total and bioaccessible) in the leaves of the analyzed plants

In general, the bioaccessible fraction by intake is low, although it is higher in the areas most influenced by primary and secondary pollution sources. The availability of bioaccessible As in the leaves of the plants is highly influenced by the mineralogical composition of the soils on which it grows.

How to cite: Martinez Sánchez, M. J., Martínez López, S., Martínez Martínez, L. B., Bech Borras, J., and Pérez Sirvent, C.: Evaluation of the bioaccessibility of arsenic in plants used for soil recovery purposes in mining areas, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13212, https://doi.org/10.5194/egusphere-egu21-13212, 2021.

Abandoned mining areas are a clear example of the failure of the different administrations to solve the environmental problems they pose, due to the lack of unified legislation and management and the activity of geological processes. It is therefore important to have a clear vision of the environmental problems that occur and the possible actions to solve them.

The Sierra Minera (Cartagena, SE Spain) presents situations of risk of soil contamination that coincide with those areas with the highest content of soluble and/or bioavailable PTEs (potentially toxic elements) for the health of people and ecosystems, especially in those sites of concentration of polluting sources (flotation mud pools and heterogeneous dumps), with a very fine texture. These areas present numerous points with an urgent need for risk management due to the possible mobilization in different environmental conditions of arsenic and heavy metals, with a control of both soluble and particulate dispersion. Special interest presents arsenic mobilisation in an acidic environment together with reducing situations and the presence of organic matter (waterlogged marshes).

The recovery technologies to be applied in the Sierra Minera require a great diversity of techniques, depending on the uses of the land. In the contamination foci it is necessary to carry out actions with containment, stabilisation and solidification technologies in situ. Phytoremediation techniques, given the high content of PTEs present, may not all be appropriate in the different situations. Phytoextraction should only be applied in areas with low concentrations of PTEs, and by plants that do not transfer to their aerial part, to avoid the risk of ingestion by animals. Phytostabilisation will be important in combined techniques, in order to ensure that contaminants are not transferred to the environment, and by non-accumulating plants in the aerial part. Wetlands can be a complementary solution to the projects developed at the heading of wadis, providing a double purpose, natural attenuation of contamination and lamination of turbulence and floods.

A generic overview is given of the most important regeneration approaches from a geochemical point of view, without going into structural solutions, selecting those technologies that are most suitable to the environment in which they are located, trying to imitate natural attenuation processes and using eco-efficient and sustainable materials.

How to cite: Hernández-Córdoba, M., Martinez-Sánchez, M. J., Martinez López, S., Martinez-Martinez, L. B., Hernández-Pérez, C., García-Lorenzo, M. L., Bech, J., and Pérez-Sirvent, C.: Strategies for the environmental recovery of abandoned mining areas, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13219, https://doi.org/10.5194/egusphere-egu21-13219, 2021.

Benzo[a]pyrene (BaP) is one of the most dangerous polycyclic aromatic hydrocarbon, highly persistent and toxic and its remediation by the cost-effective adsorbents are of great importance. Although various technologies have been developed to remove BaP from the environment, its sorption through solid matrixes has received increasing attention due to cost-effectiveness. Studies regarding the absorption of PAHs by soil matrix have been focused mostly on non-carcinogenic compounds comprising two or three aromatic rings, such as naphthalene and phenanthrene. However, the BaP absorption by the soil matrix and different adsorbents is not yet well explored. The present research investigates the adsorption capacity of Haplic Chernozem, granular activated carbon and biochar in relation to BaP. The Haplic Chernozem properties has following properties : clay particles content was 53.1% for particles with diameter < 0.01 mm and 32.4% for particles < 0.001 mm; pHH2O - 7.3; Corg - 129 3.7%; CaСО3 - 0.1%; exchangeable cations Ca2+ - 31.0 and Mg2+ - 4.5 cmol(+) kg−1; cation exchange capacity (CEC) - 37.1 cmol(+) kg−1. Laboratory experiments with different initial BaP concentrations in the liquid phase, and different rations of both solid and liquid phases, show that Freundlich model describes well the adsorption isotherms of BaP by the soil and both adsorbents. Moreover, the BaP isotherm sorption by the Haplic Chernozem is better illustrated by the Freundlich model than the Langmuir equation. The results reveal that the sorption capacity of the carbonaceous adsorbents at a ratio 1:20 is orders of magnitude higher (13368 ng mL^-1 of activated carbon and 3578 ng mL^-1 of biochar) than that of the soil (57.8 ng mL^-1). The difference of the sorption capacity of the carbonaceous adsorbents and soil at a ratio 0.5:20 were 17-45 times. This is due to the higher pore volume and specific surface area of the carbonaceous adsorbents than soil particles, assessed through scanning electron microscopy. The results of sorption kinetics showed high sorption rates and achievement of sorption equilibrium after 1 h. Biochar adsorbed BaP more intensely than granular activated carbon. The sorption kinetic of  BaP by chernozem was compared with the adsorption kinetics by the carbonaceous adsorbents. Results indicate that the adsorption dynamic involves two steps. The first one is associated with a fast BaP adsorption on the large available surface and inside macro- and mesopores of the sorbent particles of the granular activated carbon and biochar. Then, the adsorption is followed by a slower process of BaP penetration into the microporous space, and/or redistribution into a hydrophobic fraction. Overall, the granular activated carbon and biochar are highly effective adsorbents for BaP, whereas the Haplic Chernozem has a rather limited capacity to remove BaP from contaminated solutions.  

The research was supported by RFBR, projects no. 19-29-05265 and 19-34-90185.

How to cite: Dudnikova, T., Minkina, T., Vasilyeva, G., Bauer, T., Barakhov, A., Sushkova, S., Pinskii, D., Mazarji, M., and Ferreira, C.: Comparative sorption of benzo[a]pyrene by soil and carbonaceous adsorbents, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-15977, https://doi.org/10.5194/egusphere-egu21-15977, 2021.

Long-term coal mining in the Moscow basin has a complex negative impact on soils of natural ecosystems. Due to underground mining operations at coal deposits in the Moscow basin spoil heaps with a high content of iron sulfides and aluminosilicates were formed. Active oxidation of sulfides in waste dumps results in the producing of toxic sulfuric acid and iron sulfates (Nordstrom and Alpers 1999). Acid mine drainage (AMD) of sulfuric acid, Al and Fe sulfates as well as pyritized material, entering from eroded spoil heaps, results in physico-chemical and morphological changes in soil properties. On foreslopes around spoil heaps technogenically transformed soils are common. Our study aimed at evaluation of post-mining geochemical transformation of soil properties, which is adjacent to spoil heaps.

We observed two key sites within abandoned coal mines in the western part of Moscow basin (the Tula region, Russia). Prevailing natural soils are Umbric Albeluvisols and Umbric Podzols (sod-podzolic soils and sod-podzols in Russian classification). Soils with transformed water regime are formed in mine subsidence.

Soil samples and displaced soil solutions (by ethanol) were analysed for acid-base properties, content and composition of readily soluble salts, content of Fe²⁺ and Fe³⁺, H⁺ and Al³⁺, composition of exchangeable cations, total content of S, Al, Fe, heavy metals (HM) and organic carbon).

Properties of newly formed soils differ significantly from natural soils. We identified the transformation of the composition of soil solutions. The basic geochemical processes in contaminated soils are as follows: the acidification and changes in the composition of ions in soil solutions from bicarbonate-sulfate-calcium to sulfate-iron-aluminum-calcium; cation exchange, leading to the replacement of Cа²⁺ and Mg²⁺ ions by Al³⁺ and H⁺ ions, and, probably, by Fe²⁺ and Fe³⁺ in soil ion-exchange complex. Transformed soils were characterized by a very low degree of base saturation (less than 20%). Estimation of the saturation degree of liquid phases of transformed soils with poorly soluble compounds revealed a high oversaturation of soil solutions with Fe³⁺ and Al³⁺ hydroxides. The total content of HM in transformed soil profiles were lower than background values due to the removal of soil reserves of elements in highly acidic conditions (pH<4.5). Among the morphological features of transformed forest soils intensification of podzolization process (acid hydrolysis of fine clay fractions of aluminosilicates) as well as; ferrugination (segregation of ferric iron, mainly in amorphous or poorly crystallized forms) and carbon enrichment of coal origin can be noted. Due to AMD impact that had destroyed fine clay minerals, numerous clarified areas were formed, composed of quartz and feldspar. Semi-hydromorphic soils with signs of gleying and peat accumulation were formed in subsidence areas.

How to cite: Kostin, A., Krechetov, P., Chernitsova, O., and Terskaya, E.: Geochemical alterations of forest soils in post-mining area (the Moscow brown coal basin, Russia), EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16057, https://doi.org/10.5194/egusphere-egu21-16057, 2021.