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Innovative and holistic approaches to prevent, assess and mitigate soil pollution: integrating natural solutions with advanced data analysis and digital tools

Soil pollution is a worldwide problem, which can result in a negative impact in (terrestrial) ecosystems, surface and groundwater, and the food chain. According to the European Commission, there are around 2.8 million soil pollution events contributing to soil pollution. Of these, 25 % have been identified and registered, but only 5% need mitigation strategies. In order to address soil pollution and develop preventive and mitigation strategies, it is necessary to invest in (i) the identification and characterization of these sites, from contaminant identification to ecosystem characterisation, and (ii) the identification of potential solutions. This requires linking new strategies (e.g. machine learning, artificial intelligence, digital data mapping) with natural solutions (e.g. soil-microorganisms-root-plant interaction). We welcome our colleagues to present their latest and ongoing findings and look forward to establishing new partnerships to create holist strategies that can help to prevent, assess and mitigate soil pollution consistently and swiftly.

Co-organized by BG2/GI2
Convener: Maria Manuela Abreu | Co-conveners: Selma PenaECSECS, Patrícia Vidigal, Antonio Aguilar-GarridoECSECS, Stefano Albanese
| Tue, 24 May, 13:20–14:50 (CEST)
Room -2.47/48

Tue, 24 May, 13:20–14:50

Chairpersons: Maria Manuela Abreu, Patrícia Vidigal, Stefano Albanese


Antonio Aguilar-Garrido et al.

In the coming years, food demand will increase sharply in line with population growth. So, production will have to increase mostly by area expansion, which could lead to biodiversity loss and an increase in greenhouse gas emissions. Furthermore, both land and water resources are limited and already under severe pressure, making it imperative to ensure a more productive but also sustainable agricultural system. A possible solution to this could be the reclamation of marginal lands, such as saline and drought-prone lands, or even abandoned mining areas. In this sense, phytostabilisation is considered a suitable method for their rehabilitation and reconversion to agricultural and livestock activities while protecting the food chain. Some pasture plants can tolerate adverse growth conditions, such as mine waste or soil conditions (e.g. high concentrations of potentially hazardous elements (PHE) and EC, low pH, organic C and nutrients, and poor structure and water holding capacity). However, low and slow plant growth can limit environmental rehabilitation success. The combined use of Technosols and pastures may be an effective green technology towards reclaiming these marginal areas for food production. To verify this hypothesis, we studied the development of a biodiverse pasture in two biogeochemically distinct Technosols. The pasture is composed of leguminous plants of the genus Trifolium sp. (T. michelianum var. paradana Savi, T. vesiculosum var. cefala Savi, T. resupinatum var. nitrofolus L., and T. squarrosum L.) and Medicago sp., and gramineous plants such as Lolium multiflorum Lam. Two Technosols have been built using a saline Fluvisol collected in the Tagus Estuary and a gossan waste from the São Domingos mine together with a mixture of organic and inorganic amendments. The microcosm assay consisted of four treatments set up in pots of 1.5 dm3 volume (four replicates): (i) Fluvisol (VF), control of salinity affection (EC: 7.9 dS/m; exchangeable sodium 25%); (ii) Technosol-Fluvisol (TVF); (iii) gossan waste (G), control of PHE contamination (g/kg As: 9.1; Pb: 29.6) ; and (iv) Technosol-Gossan (TG). One month after sowing (5 g seeds per pot), the pasture biomass generated so far was mowed to simulate livestock grazing. Pasture in FV showed no seed germination, thus no plant growth. In contrast, in G (10 cm stem length and 1.41 g DW), was observed seed germination followed by plant growth, with gramineous dominating over leguminous plants. In the Technosols, pasture growth improved extraordinarily, with plants reaching more than 15 cm stem length and higher biomass with 2.59 g DW on TVF and 3.8 g DW on TG. Moreover, the pasture was more biodiverse, with the presence of as many leguminous as gramineous. Upon the first cut, the pasture was left for another month for the plants to regrow, and then mowed for the last time. During this time, L. multiflorum has kept growing to similar sizes to the first mowing, while the leguminous have not regrown as effectively. Thus, an integrated biotechnological approach involving Technosols and pastures could be a useful green technology to convert marginal lands into food production areas (grazing or foraging).

How to cite: Aguilar-Garrido, A., Vidigal, P., Caperta, A. D., and Abreu, M. M.: Development capacity of a biodiverse pasture on Technosols for the rehabilitation of marginal lands (saline soils and mining waste), EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-121, https://doi.org/10.5194/egusphere-egu22-121, 2022.

Nataliia Chupakhina et al.

Method of isolation of soil microorganisms - destructors of biopolymers

Nataliia Chupakhina, Nadezda Nikolaeva, Dmitriy Nechaev, Nadezda Medjalo, Anastasija Novichkova, Valerija Lobanova and Galina Chupakhina

School of Life Sciences, Immanuel Kant Baltic Federal University, Universitetskaya str. 2, 236040 Kaliningrad, Russian Federation

Biological degradation of plastic by microorganisms and their enzymes is one of the ways to eliminate the waste resulting from mass production of plastic (Carr C. M., Clarke D. J., 2020).
We analyzed the soil microflora in the presence of fragments of oxo-biodegradable polyethylene with the addition of d2w. The experiment was conducted in the historical center of the city with medium-rise buildings and mass landscaping. We took soil samples at a depth of 10 cm in accordance with GOST The soil was classified as heavy sandy loam with the pH of 7.4. Soil suspension (1 g of dry soil per 100 ml of sterile water) in an amount of 100 ml was distributed on solid nutrient media Nutrient dry agar, Nutrient broth with agar addition, GMF broth with agar addition (pH 7.3), sterilized in an autoclave for 20 min at 121 °C. The cultivation regime consisted of keeping the Petri dishes in a thermostat at a temperature of 37 ° C in the range from 1 to 7 days. When using dry soil, bacteria could not be isolated. We repeated the experiment using raw soil. The highest number of diverse colonies had grown on the Nutrient Dry agar medium. After the growth of a large number of microorganisms on Petri dishes, 20 non-repeating colonies of bacteria were isolated.

Next, we placed 5-7 polyethylene discs with the diameter of 7 mm on Petri dishes with 20 isolated colonies. We washed the discs with soap, soaked them in alcohol and rinsed them with autoclaved water. The bacteria were cultured in a thermostat at 37°C for 1 - 7 days. The maximum reliable biofouling of the polymer was recorded on day 7 in 50% of the cups with a double complete repetition of the experiment. 

We can conclude that in order to isolate the soil bacteria aiming to find out their destructive activity against biodegradable plastic, it is effective to use a soil from a depth of 10 cm in suspension with sterile water (1g per 100ml) and cultivate it on Nutrient dry agar (pH 7.3) at 37 ° C for 7 days.

How to cite: Chupakhina, N., Nikolaeva, N., Nechaev, D., Medjalo, N., Novichkova, A., Lobanova, V., and Chupakhina, G.: Method of isolation of soil microorganisms - destructors of biopolymers, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-2063, https://doi.org/10.5194/egusphere-egu22-2063, 2022.

Abdul Kadir Ibne Kamal et al.

This study aimed to assess how the root system of Sesbania cannabina behaves under various concentrations of Cr (VI) and whether it could be a suitable species for the phyto-management of Cr (VI) contaminated soils. The experiment was conducted in rhizoboxes under greenhouse conditions using a sandy loam soil dosed with potassium dichromate giving eight different Cr (VI) concentrations (0 ppm, 5 ppm, 10 ppm, 20 ppm, 40 ppm, 80 ppm, 160 ppm, and 360 ppm). Plant roots were photographed with a Canon 60D (18-megapixel) camera with a 50 mm prime lens and analysed with Image J image processing software.

At 360 ppm concentration, seeds of S. cannabina germinated but were unable to grow further. However, under concentrations of 0-80ppm there was no significant change observed in the root growth (Length) . At 160 ppm root growth was reduced by about 55±0.65% at 25 days and 35±0.25 % at 60 days compared to plants grown at 0 ppm. After 60 days no chromium (VI) was detected in the soil for (0 to 160 ppm) in comparison with the control (with no plants) where no changes in Cr (VI) were observed.


The absence of Cr (VI) in soil after 60 days suggests that S. cannabina can be considered as a candidate for phyto-management of soils containing up to 160 ppm Cr (VI).

How to cite: Ibne Kamal, A. K., Batty, L., and Bartlett, R.: Evaluation of the root system and phyto-management potential of Sesbania cannabina grown in hexavalent chromium contaminated soils utilizing modified rhizobox systems., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4921, https://doi.org/10.5194/egusphere-egu22-4921, 2022.

Lorenzo Panzeri et al.

Although the indications contained in the European New Green Deal aim to inhibit the opening of new waste disposal sites through a circular economy of waste materials, the management of an extremely large number of municipal solid waste landfills (MSWLF) at different stages of their life cycle is a highly topical issue. Recent national regulations in Italy require the operators to monitor subsoil conditions for 30 years, but do not define clear and unambiguous guidelines.

According to analyses carried out at various landfill sites in northern Italy, monitoring activities were often found to be set up with wells equipped with piezometers. This approach is not optimal because when any contaminants are intercepted by the wells, the conditions of the subsoil may already be compromised. Therefore, the goal of our work is to develop methodologies to test and define an effective monitoring protocol that allows to mitigate the environmental and ecological risks associated with the subsurface propagation of pollutants at MSWLF sites.

The analysis of the subsoil conditions involves the design of monitoring methodologies and the interpretation of the obtained results, exploiting geological, hydrogeological and geophysical knowledge and skills. Accordingly, we rely on a research methodology based on the mutual and continuous exchange between the involved disciplines, starting from the initial geological assumptions that will be used to define a physical model of the subsurface. We mainly resort to indirect non-invasive techniques, in particular to the direct current (DC) electrical resistivity tomography (ERT) that on the one hand is indicated for identifying conductive anomalies associated with the propagation of pollutants, but on the other hand constitutes a complex ill-posed numerical problem. The major issues are related to the spatial resolution and the penetration depth of the technique that in turn control the capability to detect presence and the conditions of the extremely thin high-density polyethylene (HDPE) membrane used to isolate the landfill waste from the surroundings.

To tackle the abovementioned issues, we decided to perform properly downscaled laboratory experiments in order to test the effectiveness of DC methodology in controlled and well-known settings. Processing and interpretation of the collected geoelectrical data are supported by a new modelling code in Python programming language that is being developed.

We deem that the integration of lab and modelling tests is necessary to propose a sound standard approach to address complex and multidisciplinary problems related to landfill risk management.

How to cite: Panzeri, L., Papini, M., Formaggia, L., Scotti, A., Fumagalli, A., Arosio, D., and Longoni, L.: Lab and modelling tests to develop a geoelectric monitoring system for municipal solid waste landfills, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-7788, https://doi.org/10.5194/egusphere-egu22-7788, 2022.

Antonio Aguilar-Garrido et al.

The influence of six different Technosols on solubility and potential toxicity of metal(loid)s from polluted soils was studied. Technosols were made with a soil affected by residual pollution coming from the Guadiamar Green Corridor and different combinations of three organic wastes [solid olive-mill (T1 and T4), sewage sludge (T2 and T5), and gardening vermicompost (T3 and T6)]. In addition, carbonate-rich material from a peatbog was applied to T1, T2, and T3; while marble sludge was added to T4, T5, and T6; iron-rich sludge (2%) was also applied to all Technosols. The comparison with a non-polluted soil from the study area is also included. Main soil properties (pH, EC, and OC) and solubility of potentially harmful elements (PHEs) in a soil:water extract (1:10) was measured both in Technosols as in soils after two months of incubation period. Potential toxicity was estimated by a germination bioassay with Trifolium pratense L.

The different Technosols showed changes in the solubility of PHEs with significant differences between elements. Cu and Zn strongly reduced the solubility in T3 and T6 in relation to the polluted soil; Cd was reduced in all cases without significant differences between Technosols; and Pb increased in Technosols treated with solid olive-mill (T1 and T4) and sewage sludge (T2 and T5). A significant increase in the solubility of As and Sb was detected in all cases. Likewise, soil treated with Technosols showed differences in solubility of PHEs. Cu and Zn were strongly reduced in the soil treated with T6, and Cd and Pb was reduced in all cases. Arsenic was reduced in all treated soils, although the soluble concentration remained slightly above the values of non-polluted soil. While Sb solubility increased in soils treated with Technosols made with carbonate-rich material from a peatbog (T1, T2, and T3), and maintained at the same level as in polluted soils for soils treated with Technosols made with marble sludge (T4, T5, and T6). These behaviours are mainly related to the increase in calcium carbonate content and the rise in pH in Technosols compared to the polluted soil. The germination bioassay with T. pratense showed very high toxicity (no germination) in soils treated with sewage sludge (T2 and T5), high toxicity (>75% reduction in germination in relation to non-polluted soil) in soils treated with solid olive-mill (T1 and T4), and low toxicity (15% reduction in germination in relation to non-polluted soil) in soils treated with gardening vermicompost (T3 and T6).

Our results indicate that the Technosol composed of gardening vermicompost were the most effective in the reduction of PHEs solubility and toxicity; however, additional studies should be made to assess the increase of mobility in As and Sb after Technosol treatment.

How to cite: Aguilar-Garrido, A., Romero-Freire, A., Paniagua-López, M., Martínez Garzón, F. J., and Martín-Peinado, F. J.: Changes in the solubility and potential toxicity of metal(loid)s in soils treated with Technosols, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8337, https://doi.org/10.5194/egusphere-egu22-8337, 2022.

Elena Korobova et al.

A detailed study of 90Sr distribution in the overground vegetation cover within an elementary landscape geochemical system (top-slope-closing depression, ELGS) was performed in several forested and meadow test sites located in the Eastern Urals Radioactive Trace highly contaminated with this technogenic radionuclide during its release in the Kyshtym accident in 1957 (INES level 6). After selecting the suitable test sites, they were crossed by several lateral profiles along which relative altitude with a step of 1 m and precision of 1 cm was measured using theodolite Boif-DJD10. Averaged plant samples were taken at each point within a standard steel ring (14 cm diameter) later separated into the groups of cereals, legumes and other different herbs. Particular species were also collected if present at no less than seven consequent points. Strontium-90 activity was measured by the portable complex ”Colibri” (SKS-08P) developed in the Kurchatov Institute (Potapov et al., 2021). It allowed the measurement of radionuclide activity in field conditions. The determination error did not exceed 15%. Analysis of data obtained revealed the ordered variation of 90Sr in all groups of plants. This order was presented by the cyclic (periodic) change of 90Sr activity downslope without definite radionuclide accumulation at the foot of the slope and in depression as usually expected. A similar cyclic pattern was found for 137Cs variation in moss cover studied in the Chernobyl zone (Dolgushin & Korobova, 2021). We consider it reflects peculiarities of water migration in the soil-plant system at the ELGS scale. Specific 90Sr activity in forest grasses correlated with biomass volume while plant groups and species with the different activity of radionuclides significantly differed in 90Sr variation amplitude and its maximum values. The revealed features of variation likely reflect the peculiarities of 90Sr water migration in soils, the structure of root system, and the plants' ecological demands, such as their hydrophilicity.


Potapov, V.N., Ivanov, O.P., Luk’yanov, V.V. et al. Portable β-Spectrometer for 90Sr Activity Field-Measurements in Radioecology and Rehabilitation of Nuclear Energy Facilities. At Energy 129, 155–162 (2021). https://doi.org/10.1007/s10512-021-00728-5

Dolgushin, D. and Korobova, E.: New data on the character of 137Cs lateral and vertical migration in soil-litter-moss cover within undisturbed elementary landscape geochemical systems on the test site in the Chernobyl abandoned zone, Russia, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-7691, https://doi.org/10.5194/egusphere-egu21-7691, 2021.

How to cite: Korobova, E., Baranchukov, V., Dolgushin, D., Tarasov, O., and Mikhailovskaya, L.: About the character of variation of 90Sr concentration in plants within elementary landscape geochemical system, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-8381, https://doi.org/10.5194/egusphere-egu22-8381, 2022.

Ana Cristina González-Valoys et al.


The Remance gold mine, in Veraguas (central Panama), had its last mining operation in 1999, using the cyanidation process for Au separation. As a result of this activity, three waste tailings were exposed to the weather, in addition to mine dumps and the open pit mining areas. Currently the area is inhabited by peasants who develop subsistence agriculture and livestock. Therefore, the objective of this study has been to evaluate the environmental and human health risks that this area represents. The total concentrations of potentially toxic elements (PTEs) such as As, Cu, Zn, Ba, Sb and Hg were determined in mining process areas, surrounding soils and edible and inedible plants in the area; in addition to the cyanide species and the enzymatic activity by dehydrogenase (DHA) in soils. The accumulated contamination index (PLI) and potential ecological risk (RI) were calculated, the carcinogenic (CR) and non-carcinogenic (HQ) risk to human health represented by soils and edible plants was estimated.

Regarding the degree of contamination, it is observed that the contamination is considerable in the tailings and the sediments of the pithead, and it spreads to the surroundings mainly in the sediments of the streams and their terraces, and, to a lesser degree, to the soils around it, showing that the main route of dissemination is through runoff; the same trend is followed by the potential ecological risk, being extreme in the sediments of the pithead, serious in the tailings and terrace sediments, high in the stream sediments and medium in the surrounding soils. The enzymatic activity by DHA tells us that the health of the surrounding soils is better than that of the stream sediments and terrace sediments, but less than in other sites affected by mining activity in Spain. Cyanide species are linked to DHA and this in turn is favoured by organic matter (OM). On the other hand, it was observed that cyanide elutes from the tailing’s piles in a complex cyanide way, favouring the transport of PTEs associated with it to the stream sediments.

Regarding the risks to human health in soils, As and Cu concentrations exceed the limits for non-carcinogenic and carcinogenic risk in both children and adults, with the residential scenario being the worst scenario, and for adults also the agricultural scenario. In edible plants such as rice, corn, cassava and tea leaves, Sb exceeds the limit for non-carcinogenic risk, and Cu and As for carcinogenic risk. Due to the potential ecological and human health risks that the area represents, actions must be taken to reduce them.

Keywords: potentially toxic elements (PTEs), gold mine, risk assessment, edible plants, human health.

How to cite: González-Valoys, A. C., Esbrí, J. M., Jiménez Salgado, J. U., Rodríguez, R., García-Noguero, E. M., Monteza-Destro, T., Vargas-Lombardo, M., Garcia-Ordiales, E., Arrocha, J., Martínez, E., Campos, J. A., Gutierréz, E., García-Giménez, R., Jiménez-Ballesta, R., García-Navarro, F. J., and Higueras, P.: Environmental and human health risks due to mining activity in the soils and plants of the Remance mine, Panama, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-9882, https://doi.org/10.5194/egusphere-egu22-9882, 2022.

Muhammad Tukur Bayero et al.

Mobilization of heavy metal ions has increasingly become a serious environmental issue globally, in the contaminated soils, calling for an urgent need to find environmentally friendly materials. With the continuing maturation of research on using biochar (BC) for the remediation of contaminated soil, compositing metal-organic framework (MOF), which is a highly crystalline porous material, has gradually attracted increasing attention. Compared with BC, BC-MOF has unique underexplored potential as an amendment for immobilization of heavy metal ions, including a high specific surface area and a large number of individual functional groups. The efficacy of BC-MOF for immobilization of toxic heavy metal contaminants in soil systems was investigated in the small leaching columns. The amendments (except BC) decreased the water-soluble and exchangeable content of Cu in Technosol compared to the unpolluted soil. The presence of MOF on the BC surface contributed to the higher immobilization efficacy, which was probably due to the synergistic effects among them. The mechanism of the immobilization process on BC-MOF was proposed. The obtained results highlight the promise of utilizing BC-MOF as a remediation material for Cu immobilization in the soil.

The research was financially supported by the Ministry of Science and Higher Education of the Russian Federation project on the development of the Young Scientist Laboratory (no. LabNOTs-21-01AB) and the Russian Foundation for Basic Research, project no. 19-34-60041 and 19-29-05265.

How to cite: Bayero, M. T., Mazarji, M., Bauer, T., Minkina, T., Sushkova, S., Mandzhieva, S., Timofeeva, A., Kızılkaya, R., and Gülser, C.: Biochar and metal-organic framework nanocomposite: Application for immobilization of Cu in polluted industrial soil , EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10121, https://doi.org/10.5194/egusphere-egu22-10121, 2022.

Maria Jose Martínez-Sanchez et al.

The use of indicators for soil monitoring is a long-established methodology that can be applied in the context of climate change. It makes it possible to establish the state of the variable to be measured and to obtain an objective signal of the changes that occur over time. Obtaining a climate adaptation indicator (CAI) for Mediterranean rainfed soils is a very useful monitoring tool for decision-making and for the incorporation of mitigation measures.

Within the LIFE AMDRYC4 project, a framework has been outlined in which a) environmental indicators of the chemical degradation of soils (salinity, alkalinity, fertility, phytotoxicity) and the erosion indicator, b) biodiversity indicators (vegetation indices, Shannon-Weaver indices, Simpson, ...) and c) organic carbon indicator have been used.  These primary indicators can be summarized resulting in a higher rank one represented by the soil ecosystem services indicator (SESI) which reflects the soil global condition obtained from the base data for each established monitoring point. By combining the SESI with a transformative indicator such as the one calculated on the basis of the increase of organic C in the soil (mitigation indicator, MI), the indicator of climate adaptation is obtained, using a procedure based on fuzzy methodology.

In the calculation of the phytotoxicity indicator, the assimilable values of selected trace elements that can cause phytotoxicity are determined and their variation over time is monitored. The selected trace elements, in this case Pb, Cd and B, may vary from one area to another depending on the geochemical background of the soil.  

The results obtained for several soil plots that have been subjected to organic matter incorporation treatments (sewage sludge, manure from different animals, composted plant remains) and their untreated counterparts (blank) clearly show an improvement of the soil characteristics after the application of the mentioned soil treatment strategies. The soils are not affected by the polluting processes, both in terms of potentially toxic elements and other emerging pollutants. The experimental data obtained indicate that the remediated soils can be useful to reduce the concentration of greenhouse gases in the atmosphere and represent a good tool for combating climate change.

The authors are grateful to LIFE16 CCA/ES/000123-LIFE AMDRYC4 Project for the financial support

How to cite: Martínez-Sanchez, M. J., Perez-Sirvent, C., Martínez-López, S., Martínez-Martínez, L., Gómez-Martínez, C., Bech, J., and Hernández-Córdoba, M.: Tools for the adaptation to climate change and monitoring of soil environmental quality., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10520, https://doi.org/10.5194/egusphere-egu22-10520, 2022.

Selma B. Pena et al.

Land use and management practices are the primary cause of land degradation, including soil loss, soil pollution, and biodiversity loss. The goal of achieving a healthy soil capable of providing a wide range of ecosystem services should be guaranteed by integrating these goals in the landscape planning system.

Landscape planning methodologies should integrate a perspective of understanding the ecological suitability for different activities to avoid the risk of taking land degradation to a level of difficulty to recover. Those methodologies also need to involve the landowners, define the best management practices, and inform about landowners' financial returns. In Portugal, municipal plans (PDM) are defined at a scale of 1:25000, binding private parties. However, they are very superficial in informing landowners about land potentiality and management practices, and they do not identify where ecosystem restoration should occur.

This work aims to show how priority areas for restoration can be identified and included in municipal landscape plans to provide a good chemical, biological and physical condition of soils. The methodology is defined in Geographic Information System (GIS), and it is based on ecological-based principles. In particular, it is shown how the headwater system's restoration could be planned. The Headwater System is located between the beginning of the water network and the ridgeline and plays an essential role in regulating water and returning quality to the soil. The best suitable land use in the headwater system is a mixed forest consisting of species of potential natural vegetation that will return nutrients to the soil, maximize organic matter, reduce the risk of erosion and regulate the water cycle, while being an essential tool for controlling human activities, also preventing actions that lead to soil pollution.

The headwaters were mapped in GIS considering a drainage area of 0.05 km2, for the study area, which comprises 55 thousand hectares. The present study evaluates the current land uses in the headwaters, identifying Hotspots for ecological restoration and identifying opportunities for improving the landscape planning system.

The results show that about one-third of the study area is made up of headwaters located in a very hilly relief with very thin soils. The dominant land uses are eucalyptus forest, shrubs, and old areas of maritime pine that burned in the 2017 mega-fires. The potential natural vegetation shows that these sites are suitable for Quercus pyrenaica, Quercus suber, Quercus robur, and Castanea sativa.

The adequate land use of the headwater system will significantly impact the ecological function of its river basin. The restoration of these areas will provide better ecosystem services by avoiding soil loss and reducing floods downstream, improving water infiltration and its quality, and increasing biodiversity. The integration of headwater restoration in the landscape planning system can be a crucial tool for attaining healthy soils.

How to cite: Pena, S. B., Magalhães, M. R., and Abreu, M. M.: Planning for a healthy landscape to provide healthy soils. Restoring the Headwater System, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-10530, https://doi.org/10.5194/egusphere-egu22-10530, 2022.

Stefano Albanese et al.

The Commune of Santiago is an administrative unit belonging to Chile's capital city. It is the central hub for local transportation services and the centre of most national government functions. In 2017, a geochemical survey was carried out focusing on the topsoils of the commune. A total of 121 samples were homogeneously collected across an area of 22.4 sqkm to determine the spatial distribution of potentially toxic elements (PTE) and discover their primary and secondary sources. In the aim of the work, the assessment of human health risk for the local population was also included considering both the direct contact with soils and the breathing of airborne particles as relevant exposure pathways.
The geochemical baseline maps of 15 PTEs were generated using the Multifractal IDW (MIDW) interpolation, and map intervals were determined using a Concentration-Area plot considering the fractal structure of the geochemical data.
The contamination degree of the urban soil and its pattern was also calculated and mapped after developing a new index, named as Cumulative Contamination Degree (CCD), which integrate information about the severity of contamination and its spatial complexity.
A robust multivariate statistical analysis based on Principal Components (RPCA) was carried out considering the compositional nature of the geochemical data. In addition, to highlight the presence and the geochemical patterns depending on different contamination sources, a Sequential Binary Partition (SBP) was used to generate contrasts among those elements considered as proxies of specific processes (Urban traffic, productive settlements, etc.).
A probabilistic approach was chosen to assess the risk due to exposure to soils for the local population. It was based on Monte Carlo simulation to include uncertainty due to spatial variation of data and the relative mobility of people within the borders of the study area. 
The results obtained show that the innovation proposed to assess contamination and discriminate its sources, even when they are of secondary relevance, can generate positive feedback. Using a probabilistic approach in a non-site specific framework can even be considered a more reliable method to assess risks if we want to not underestimate the burden of uncertainty that substantially influences the results. 

How to cite: Albanese, S., Aruta, A., Daniele, L., Cannatelli, C., Buscher, J. T., De Vivo, B., Petrik, A., Cicchella, D., and Lima, A.: Integrating methods to discriminate the soil historical pollution sources and assess the degree of contamination and related health risks in an urban environment:  the Commune of Santiago (Chile) case study., EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-11920, https://doi.org/10.5194/egusphere-egu22-11920, 2022.

Mario Paniagua-López et al.

The present study evaluates the potential toxicity of the soils of the Guadiamar Green Corridor (GGC) (Seville, SW Spain) affected by the Aznalcóllar mine spill, one of the most important mining accidents in Europe in recent decades. Twenty years after the accident, soils affected by residual contamination are still present in the area, for which their potential toxicity was assessed by carrying out bioassays with lettuce (Latuca sativa L.), earthworms (Eisenia andrei) and determining the microbial activity by measuring the basal respiration and the microbial metabolic quotient (qCO2) of these soils at surface level (0-10 cm). A total of 84 soil samples were taken along the GGC, which were divided into four types (SS1-SS4) according to their physicochemical properties. Soils SS1 and SS2 showed a higher environmental toxicity risk, with a reduction in root elongation of lettuce seeds of 57% and 34% compared to the control, as well as a higher metabolic quotient (23.9 and 18.1 ng CcO2 µg Cmicrob-1 h-1), significantly higher than those measured in SS3 and SS4.

The potential risk to humans of these soils through ingestion, inhalation, and skin exposure routes for the main potentially toxic elements (PTEs) present in the GGC (Pb, and As) was also evaluated based on EPA empirical models, in which the total exposure through each of the three routes was considered. The results obtained indicate that there is no potential risk for human health throughout the GGC considering the exposure for both adults and children, although there are areas of the corridor where the Guideline values for both Pb and As are exceeded. This, together with the potential toxicity of the soils to the ecosystem shown by the bioassays, indicate the need to monitor over time the human and environmental risks in the area to guarantee the safety and enjoyment of this natural area.

How to cite: Paniagua-López, M., Pastor-Jáuregui, R., Aguilar-Garrido, A., Romero-Freire, A., and Sierra-Aragón, M.: Ecotoxicological risk assessment of the Guadiamar Green Corridor soils 20 years after the Aznalcóllar mining accident, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12397, https://doi.org/10.5194/egusphere-egu22-12397, 2022.

Diego Aran et al.

In Portugal, there are numerous abandoned mines, many of them derived from an intense activity in massive sulfides. These areas have several environmental problems associated to extreme physicochemical characteristics of their wastes and leachates.

In São Domingos mine, there is an additional environmental problem derived from the percolation of acid mine drainage over the slopes. This measure, used in environmental management of waters, contributed to the total degradation of the edaphic system and enrichment of bedrock in potentially toxic elements (PTE). A sustainable strategy for environmental recovery using Technosols, designed specifically for each contaminated or degraded material, has been evaluated in this scenario. A pilot area, with ​​1.5 ha, was rehabilitated by applying a 40 cm layer of Technosol with alkaline and eutrophic properties. A biodiverse plant system with herbaceous and shrubs was applied. The efficiency of the Technosol was evaluated at short-medium term by: a)several indicators associated to plant development (visual signs of phytotoxicity or nutritional deficiency, percentage of plant cover and height) after 15 days, 1, 3 and 6 months, and b)the maintenance of soil properties after 6 months. An area without Technosol application was used as control.

In Control area, plant cover was low, with maximum values ​​of 8.8% in the third month and height <10 cm. However this vegetation cover was not with the sown plants but only native species, like Spergularia purpurea (dominant species identified) that already existed in the area.

In the area with Technosol application, the plants did not show visible signs of phytotoxicity or nutritional deficiency. The percentage of plant cover increases rapidly. After 15 days plant cover was 10–30% and between first and third month, when there were warmer and dry conditions, the coverage increased to 70% and 90%, respectively.  After 6 months, coinciding with a change in the vegetative cycle and very dry and hot period from summer, the vegetation only decrease ≈10%. The height varied between 40 to 60 cm, reaching these maximum values in the third month. The plant development remained during the monitoring period. This plant evolution shows the significant water-holding capacity and fertility of the Technosol.

After 6 months, Technosol samples maintained the alkaline and eutrophic properties and physico-chemical characteristics (pH 7.5–7.8, 85 g C/kg, 6 g N/kg, Capacity of cation change 54.3–73 cmol+/kg). In the Technosol was not verified an enrichment by PTE, due to its direct contact with acidic and contaminated material. In Control area, the substrate maintained acidic reaction conditions (pH 3.5–3.6), very low fertility and high concentration of several elements.

Application of the Technosol contributed to the environmental recovery of mine areas, with very acid material with multielementar contamination where it is inexistent an edaphic system. This green technology is an effective solution to the conversion non-productive areas to productive areas.

Acknowledgment: This work was executed by EDM under a concession contract for environmental remediation of legacy mines in Portugal, in collaboration with ISA-ULisboa, LEAF and Inproyen, and was financed by POSEUR EC Cohesion Funds (145/POSEUR/2020). This research is into the scope of the project UID/AGR/04129/2020.

How to cite: Aran, D., Abreu, M. M., Diamantino, C., Carvalho, E., and S. Santos, E.: Recovering abandoned mine area under semi-arid conditions with Technosols: a pilot assay in São Domingos legacy site, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12578, https://doi.org/10.5194/egusphere-egu22-12578, 2022.

Erika S. Santos et al.

Sulfide mine tailings present particular challenges in terms of risks of environmental recovery due to the acid lixiviation rich in several metal(oids) and sulfates. The conventional closure systems of these tailings have very high cost of implementation and, especially, maintenance of plant cover and continuous leachates treatment. Therefore, the improvement of the chemical characteristics of the tailings and their leachates is a more cost-effective strategy, especially if sustainable technologies are used. The use of designed Technosols is an option. The current study advances past field and laboratory findings by integrating a circular-economy approach into the chemical and soil science-based treatment of such tailings.

A column assay under controlled conditions was set up in order to evaluate the efficiency of a designed Technosol, applied into two ways, on the chemical improvement of the leachates from sulfide-rich tailing. A designed Technosol with alkaline and eutrophic properties was mixed with tailing material (TEC1) or applied as a superficial and distinct layer (TEC2). Tailing without treatment was used as control. The evolution of pH, Electrical conductivity (EC), Fe and sulfates levels was evaluated during 6 weeks in percolated leachates.

The tailing material was previously assessed as having pH ≈2.5 and total concentrations of 104-110 g Fe/kg and 60.0-67.5 g S/kg. Percolated leachates had a pH values between 1.73 and 2.68  and high EC (≈10 mS/cm) that indicate the high amount of several elements and, consequently, their environmental risk.

The first week’s pH increased to ≈6.5 for the TEC1 while in TEC2 was ≈2.5. Following weeks, the pH stabilized at around 7.3 in the TEC1 and 2.6 in the TEC2..  The EC decreased in the first week 73% in the TEC1 and 81% in the TEC2, compared to control. In control, EC presented upwards spikes within the first two weeks, reaching almost 14 mS/cm, and then more stable values. . Notably, the EC for TEC 1 was low (<1.6 mS/cm) and rather stable throughout the experiment, for TEC2 it presented large, gradual drops in the first two weeks, followed by rather stable value  and slightly lower than control. Fe concentrations largely mirrored these EC patterns. Iron concentrations in control were high varying 60 and 7546 mg/L during the assay. Technosol application was effective in the diminution of Fe concentrations in the leachates (TEC1 > 1000-fold and TEC2 2-100 fold lower than control).

Overall, both application mode of the Tecnhosol contribute to improvements in the leachates quality. Nonetheless, these results showed that TEC1 approach might result in more stable and better chemical quality of the leachates. Importantly, these findings also suggest the improvement in the tailing structure of TEC1 compared to TEC2, contributing to lower risk of lixiviation into the lower layers.

Acknowledgment: This research was supported by Fundação para a Ciência e Tecnologia, within the scope of the project UID/AGR/04129/2020 (Project Non-foodCropMine).

How to cite: S. Santos, E., Pastrac Lungu, A., and Arán, D.: Effect of Technosol application way on chemical quality of percolated leachates from sulfide-rich tailing, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-12756, https://doi.org/10.5194/egusphere-egu22-12756, 2022.