SSS7.6

Key issues to face polluted soils: spatial variability assessment of soil contamination, aimed to site characterization/remediation, and circular economy towards site recovery

Soil pollution is a worldwide problem degrading soils with a direct impact on food security, human health and the environment. Unsustainable farming practices, industrial activities and mining, untreated urban waste have progressively contaminated soil, air and water. The spatial variability of contamination is a crucial problem when evaluations are required to address reclamation or phytoremediation on agricultural or industrial contaminated sites, because location, content, nature and form of potentially toxic elements (PTE) and/or chemical compounds are usually little-known. Proper investigation tools are necessary to identify the geography of soil contamination, as well as the variability (in space and depth) of soil chemical, physical and hydrological properties, due to their direct influence on soil capacity to filter and buffer contaminants, degrade and attenuate negative effects of PTE and chemical compounds. Soil remediation techniques using several wastes are effective for the recovery of soil properties and fertility whilst decreasing pollutants bioavailability, thus stimulating circular economy (recycling of organic and inorganic wastes), which is a key aim of the new Green Deal policy framework to stimulate lead markets for climate neutral and circular products, in the EU and beyond.
Under this perspective, this session has the aim to converge research studies presenting the most relevant advances on i) the use of ground-breaking technologies aimed to the knowledge of spatial variability of soil pollution and ii) application of soil remediation techniques in the framework of the circular economy.
Main topics addressed: use of sensors and field techniques for soil spatial variability and pollution assessment, mapping of soil organic and inorganic contaminants, contamination affecting soil ecosystem functions and services, precision remediation actions and technologies applied to contaminated sites towards circular economy, modelling of soil hydrological properties as media to forecast and prevent groundwater pollution, Spatial Decision Support Systems as policy tools for monitoring and managing soil pollution.

Convener: Simona Vingiani | Co-conveners: Maria Manuela Abreu, Stefano Albanese, Diego Arán, Jaume Bech, Piero Manna, Carmen Pérez-Sirvent, Patrícia Vidigal
vPICO presentations
| Mon, 26 Apr, 15:30–17:00 (CEST)

vPICO presentations: Mon, 26 Apr

Chairpersons: Stefano Albanese, Maria Manuela Abreu
15:30–15:35
Soil characteristics and PTE
15:35–15:40
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EGU21-8055
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ECS
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solicited
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Highlight
Samdandorj Manaljav, Andrea Farsang, Péter Balling, and Izabella Babcsányi

Intense soil erosion in sloping vineyards can substantially change the spatial quality patterns of soil that may ultimately affect plant nutrition. Our study aimed to assess spatial patterns of topsoil quality and evaluate if the topsoil-bound potentially toxic element (PTE) contents are linked with those in vine leaves. The study was conducted at a 0.4 ha plot in Tállya (in Tokaj-Hegyalja, NE Hungary), where Cambisol is the main soil type. Ploughing is regularly practiced in the vineyard, while no cover-crops are used, and sedimented soil material from the footslope area is occasionally redistributed on the hillslope. A total of 20 topsoil samples (0-10 cm) and 11 vine leaf (Vitis vinifera) samples were collected in May 2020. The moderately acidic soil (pH(d.w.): 6.12-6.92) developed on a magmatic base rock (rhyolite) showed high gravel contents ranging from 31% to 48%, a low to moderate soil organic matter (SOM) content with a mean of 1.49%, low carbonate contents (0.4-2.01%), and clay loam texture at the hillslope, while sandy clay loam at the footslope. The concentrations of bioavailable  Fe, Mn, and Cu (extracted in 0.05 M NH4-EDTA) showed high ranges in the soil: 62–258 mg kg−1, 40-114 mg kg−1 and 46-110 mg kg−1, respectively. On the other hand, Zn, Pb, Ni, and Cr concentrations were low with mean±stdev: 6±4 mg kg−1 for Zn, 4±1 mg kg−1 for Pb, 1.5±0.5 mg kg−1 for Ni, and 0.1±0.1 mg kg-1 for Cr. Increased Cu bioavailability can be explained by the regular use of Cu-based pesticides. The highest total PTE contents in vine leaves were observed for those PTE that are important micronutrients for vine plants (mean±stdev): 90±13 mg kg−1 of Fe, 167±88 mg kg−1 of Mn, 15±15 mg kg−1 of Cu and 31±6 mg kg−1 of Zn.  Zinc and Mn concentrations in leaf samples were markedly greater than their bioavailable contents in the topsoil. In contrast, lower levels of Fe and Cu prevailed in the leaves compared to their topsoil-bound bioavailable contents. Only Mn showed a significant correlation in the vine leaves and the topsoil (r=0.62).

Spatial distribution maps of the measured basic soil parameters and the bioavailable PTE contents were prepared by inverse distance weighting and ordinary kriging methods. The maps showed higher concentrations of PTEs at the summit and the shoulder of the hillslope, while lower concentrations were found at the backslope and footslope zones. The SOM showed the highest loads at the summit and the toeslope zones, while increased gravel contents were found at the backslope, confirming the effects of soil erosion dynamics and cultural practices. Our study shows that cultural practices and the lack of erosion control measures in the vineyard significantly influenced the spatial variability of topsoil characteristics and bioavailable PTEs. 

  • I. B. is grateful for the support of the Premium Postdoctoral Research Program of the Hungarian Academy of Sciences. The research received funds from the OTKA 1K 116981.

How to cite: Manaljav, S., Farsang, A., Balling, P., and Babcsányi, I.: Assessing soil characteristics and potentially toxic elements (Fe, Mn, Ni, Cu, Cr, Pb, Zn) in the topsoil and the vine leaves (Vitis vinifera) in a sloping vineyard (Tállya, NE Hungary), EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-8055, https://doi.org/10.5194/egusphere-egu21-8055, 2021.

Traditional and geophysical soil investigations
15:40–15:42
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EGU21-10808
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Highlight
Chiara Ferré, Enrico Casati, Gabriele Cerutti, Rodolfo Gentili, Alberto Francioli, and Roberto Comolli

The spatial variability of hydrocarbon content and the physical and chemical properties of the soil were assessed by combining traditional soil sampling and proximal geophysical survey with the aim of planning a pilot phytoremediation experiment in an agricultural area west of Milan (Lombardy, Italy).

The area, an irrigated arable land of about 1 ha, was affected by a refined oil spillage from an underground pipeline in 2015. Contamination surveys were carried out with a continuous core drilling technique using an hydraulic probe (131 cm diameter core). Heavy (C>12) and light (C<12) alkanes and aromatic compounds (benzene, ethylbenzene, styrene, toluene and xilenes) were measured up to three meters depth. Results showed a predominance of heavy hydrocarbons (C>12) with respect to light hydrocarbons (C<12) and aromatic compounds. A map of heavy hydrocarbons soil concentration was obtained using geostatistical techniques.

In 2019 it was decided to carry out a phytoremediation intervention to reclaim the first meter of contaminated soil where heavy hydrocarbons content ranges from 500 to 5000 mg/kg. The first step of the intervention consists in cultivating a wide variety of vegetal species in experimental plots with different pollution to verify their effectiveness for remediation in the specific environmental condition of that area. For the reclamation of deeper more contaminated layers, enhanced bioremediation have been planned to be used.

Soil properties, which are crucial for planning phytoremediation activities, were investigated using traditional methods and geophysical surveys. Traditional soil survey was performed describing the 23 drilling cores used to monitor pollutants and opening five profiles; the samples were collected from genetic soil horizons and analysed for organic carbon and the main nutrient (nitrogen, phosphorus and potassium) content, total carbonates, texture and pH in water. The distribution of Eutric Luvisols and Cambisols, developed mainly on sandy or sandy skeletal substrate, was represented in a soil map. A proximal geophysical survey was carried out using an electromagnetic induction (EMI) sensor (GSSI Profiler EMP-400) by acquiring multiple frequencies; soil detailed conductivity maps for each frequency (15000, 9000 and 2000 kHz) were obtained. No significant relationships were found between soil electrical conductivity and hydrocarbon concentration, whereas there are relationships with the main soil characteristics: this allowed detailed maps of soil parameters to be obtained.

On the base of both the soil spatial characterization (traditional soil map and detailed soil property maps with geophysical approach) and the contaminant distribution (hydrocarbon map distribution using geostatistical approach), homogeneous areas were identified in which to set up experimental phytoremediation plots to test the most suitable species for reclamation, chosen among the most widespread crops in the region and considering their suitability for biomass and bio-oil production.

How to cite: Ferré, C., Casati, E., Cerutti, G., Gentili, R., Francioli, A., and Comolli, R.: Combining traditional and geophysical soil investigation for phytoremediation planning in a hydrocarbon polluted area, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10808, https://doi.org/10.5194/egusphere-egu21-10808, 2021.

Spatial variability assessment of soil pollution
15:42–15:44
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EGU21-4969
Stefano Albanese, Annalise Guarino, Antonio Aruta, De Mascellis Roberto, Perreca Carlo, Fagnano Massimo, and Vingiani Simona

Outdoor shooting ranges provide recreational facilities for millions of people in the world. However, there are many negative effects on the environment and public health arising from this activity.

In particular, potential risks are mostly associated with the residential or agricultural use of decommissioned outdoor ranges, where bullets and targets have been deposited during the shooting activity.

This is the case of an outdoor shooting range in Campania region (Southern Italy), located in an area of historical and naturalistic value, close to the ancient Etruscan village of Suessola (VII century b.C.). Specifically, the study site is located within an agricultural land declared unsuitable for agricultural and forest-pastoral production by the Italian Ministry of Agricultural, Food and Forestry Resources, due to an extensive long term soil contamination associated with Pb, Sb, PAHs, dioxins, PCBs and C> 12 hydrocarbons.

With the purpose of planning a detailed site characterization of the shooting range area, a preliminary environmental survey was carried out by means of field investigations (ultrasonic penetrometry, electromagnetic induction - EMI -  and gamma spectroscopy) and geochemical prospecting.

Cone index data, obtained by ultrasonic penetrometer measurements, indicated the presence of a very dense, hard and impenetrable to hand hauger layer, recognised as travertine rock, from 25 to more than 55 cm of depth, and dipping northward.

Continuous EMI data and gamma spectroscopy (K %, eU ppm, eTh ppm) parameters were acquired in the field in order to identify homogeneous zones in which further geochemical investigations should have been focused. In fact, apparent electrical conductivity (ECa) map, consistently with the gamma ray dose rate distribution map, allowed to highlight three separated singularity areas  N-S oriented.

XRF analyses, carried out through a portable analyzer on soil samples collected along soil profiles digged from topsoil until the travertine layer, showed a high contamination by Pb (greater than 1000 mg/kg) and Sb (greater than 30 mg/kg) in the first 15 cm of depth, at a distance of approximately 90 m from the shooting lanes.

Chemical analyses were also performed on 32 topsoil samples collected on the basis of a regular grid across the study area. Concentrations of 13 PAHs compounds were determined and the highest values were found close to the firing lanes where in soil a huge amount of shooting target fragments are present.

The preliminary results showed how the contamination due to the previous activity in the area produced a spatial distribution of contaminats differentiated on the basis of their source material and their role in the shooting process.

How to cite: Albanese, S., Guarino, A., Aruta, A., Roberto, D. M., Carlo, P., Massimo, F., and Simona, V.: Soil pollution in a decommissioned shooting range: a preliminary survey of the spatial variability of legacy pollutants., EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-4969, https://doi.org/10.5194/egusphere-egu21-4969, 2021.

Lead contamination
15:44–15:46
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EGU21-16066
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ECS
Gorkhmaz Abbaszade, Davaakhuu Tserendorj, Nelson Salazar, Dóra Zacháry, Péter Völgyesi, and Csaba Szabó

Lead is one of the extensively distributed PTEs (potentially toxic elements) in the environment due to wide-scale anthropogenic activities (e.g., mining, vehicular emissions, industries, etc.), its geochemical feature, and natural abundance. The World Health Organization (WHO) defined Pb as 2nd most dangerous element for health, with particular concern for mental and physical disorders in adults and children. Salgótarján and Ózd cities (Northern Hungary) are two main former heavy industrial cities, with the smelter, steel industry, coal-fired power plant, coal mines, etc., supplied the country with coal and iron and steel products for centuries. The main aim of the research is to obtain a lead distribution map of the region and identify the potential sources by use of stable lead isotopes.

Urban soil samples were collected from each km2 of both cities. Additionally, a soil as geochemical background, as well as local slag and coal as suspected major pollution sources were collected. Lead content and stable Pb isotopes of all samples were analyzed by ICP-MS spectrometry.

Obtained results indicate heterogeneous distribution and high lead enrichment in both cities, where the Pb concentration ranged from 8.5 to 1692 ppm in Salgótarján and from 6.6 to 1674 ppm in Ózd. The average lead isotopic ratio in soil samples ranged from 1.146 to 1.240 (206Pb/207Pb) for Salgótarján and from 1.084 to 1.240 for Ózd. Total Pb concentration and isotopic ratios of slag and coal samples depicted notable differences as isotopic ratios for Salgótarján and Ózd coals are 206Pb/207Pb:1.175 and 206Pb/207Pb:1.256, respectively. Meanwhile, the lead content in the Salgótarján fly-ash slag (from the coal-fired power plant) was identified as 14 ppm (206Pb/207Pb:1.175, similar to coal). However, the Ózd smelter slag was characterized by high lead concentration (202 ppm) and lowest isotopic composition (206Pb/207Pb=1.118).

To calculate the relative contribution of anthropogenic sources, suggested binary mixing models were used. It is revealed that in Salgótarján soils average 34 % of Pb enters from industrial sources, 43 % from coal, and 23 % from the natural environment. In contrast, in Ózd, the proportion of anthropogenic lead is estimated on average by 53 % from industries (slag), 38 % from coal, and only 9% from natural input. The proportion of coal and slag in the soil samples was proved by thorough microscopy observations and SEM analysis as well.

In conclusion, based on the comprehensive analysis, local smelter and steel-iron industries were the dominant Pb contamination sources in both cities.

 

Keywords: Lead pollution, isotopic ratio, source identification, binary mixing model

How to cite: Abbaszade, G., Tserendorj, D., Salazar, N., Zacháry, D., Völgyesi, P., and Szabó, C.: Long-term lead contamination and isotopic source identification in Northern Hungary, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16066, https://doi.org/10.5194/egusphere-egu21-16066, 2021.

In situ PTEs measurements
15:46–15:48
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EGU21-3058
Florindo Antonio Mileti, Antonietta Agrillo, Piero Manna, Langella Giuliano, Fabio Terribile, and Simona Vingiani

All around the world, a wide range of rural and industrial areas contaminated by PTE (potentially toxic elements) is affected by general lack of ex-ante information on type, quantity and location of potentially hazardous substances, hence the increasing request of proper investigation tools enabling preliminary screening of soil environment. Besides, spatial understanding of soil contamination is a prerequisite for the achievement of both proper site characterisation and reclamation.

Continuous aquisition in field of physical soil properties (such as apparent electrical conductivity by means of EMI equipments or natural gamma-ray dose rate by gamma-ray spectrometer) is of great importance to follow soil short range spatial variability. However, when the key parameter to be monitored is the soil PTE concentration (to assess, for example, exceeding of the established screening values - CSCs), a different tool is required.  

In a farmland of South of Italy, confiscated by the Italian Judiciary due to past illegal burial of industrial wastes, a portable handheld XRF analyzer (pXRF) was used at field scale to measure PTE (As, Cd, Cr, Ni, Pb) content on soil samples collected on a regular sampling grid of 20x20 m, at three depths (0-20, 30-60, 70-90 cm). On the basis of the contaminant content, distribution maps were outlined and “spatial pollution hot spots” revealed.

In correspondence of the most contaminated areas, 8 soil trenches and 5 profiles were dug. In one of the most representative soil trenches, a large (depth/height = 200 cm and width = 500 cm) wall was in situ analysed with high detail by using the pXRF at pedon scale (measurement distance of 10 cm vertically and between 20-35 cm horizontally). The use of the software Surfer 12 enabled the spatialization and mapping of the in depth contamination. Results showed a moderate but diffuse and homogeneous Cr contamination in the topsoil (400 mg/kg), a higher but point-source (2-3%) contamination in the subsoil and uncontaminated soil (40 mg/kg) below 2 m of depth. Most contaminated soil/wastes were then morphologically described and collected, bulk samples for chemical analyses and undisturbed samples for micromorphological thin sections.

pXRF analyzer was also used at microscopical scale on soil thin sections, using a small spot collimator (analysis area of 0.07 cm2), to preliminary detect and select contaminated micro – pedofeatures, to be further sub-microscopically (SEM-EDS) analysed.

How to cite: Mileti, F. A., Agrillo, A., Manna, P., Giuliano, L., Terribile, F., and Vingiani, S.: Portable XRF analyzer: a powerful tool for multiscale assessment of soil contamination, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-3058, https://doi.org/10.5194/egusphere-egu21-3058, 2021.

Urban soil contamination
15:48–15:50
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EGU21-16203
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ECS
Nelson Salazar, Gorkhmaz Abbaszade, Davaakhuu Tserendorj, Péter Völgyesi, Dóra Zacháry, Katalin Szabó, and Csaba Szabó

Iron and steel works activities are an important industrial source of pollutants that change soil composition with a wide range of substances containing heavy metals. Determination of the multi-element composition of urban soil contributes to an accurate assessment of the quality of the urban environment. Therefore, concentrations of 15 metals (Ti, V, Cr, Mn, Fe, Co, Ni Cu, Zn, Mo, Ag, Sn, Sb, Pb and W) were measured in Ózd, a former industrial city located at the northern part of Hungary. It has been exposed to contaminants for almost two centuries by different anthropogenic activities such as transportation, coal mining, iron and steel works. In this study, 56 urban soil samples were collected from playgrounds, kindergartens, parks and roadsides, as well as 1 local coal, 1smelter slag and 2 steel slags samples.

In this study, we determined cluster distribution of the samples using compositional data analysis clr-transformed (clr-biplot), k-means cluster analysis (CA) and calculates enrichment factors (EF). To observe the relationships among the 15 metals, the clr-biplot was performed in CoDaPack software and k-means in R statistics, following recommendation in the literature [1].  The results of k-means were overlapped on the clr-biplot and plot on a map. Enrichment factors were calculated for every cluster with the formula: EF=[M/Fe]sample/[M/Fe] background, where (M) metals concentration and Fe was used for normalization. Background values were taken from brown forest soil.

The average concentration of 15 elements in (mg kg-1) for the 57 samples are Fe(27204), Mn(842), Zn(225), Ti (135),  Pb (81), Cr(41,3), Cu(30.2), V(24.2), Ni(21), Co(7.34), Sn(4.22), Sb(1.41), Mo(1.19), W(0.726) and Ag (0.268), respectively.

The optimal number of clusters are 4, where the most samples in the first cluster are distributed on the northwest side of the city where agricultural activity is a common occasion. Samples forming the second cluster are characteristic in the area of the former iron and steel factory. Samples of the third cluster are located at the new industrial park (northeast side of the city). The fourth cluster samples are derived from the surrounding area the new industrial area and covers most of the city south side. The results of average enrichment factor (EF)>5, which represent significant or very significant enrichment are 1stcluster Ti, 2ndcluster W>Ti>Sn>Ag>Cr>Pb>Sb>Zn>Cu, 3rdcluster W>Cr>Ti, and 4thcluster Ti>W.

The differences between cluster distributions and enrichment of each metallic element show complexity of the study area, which suggested areas with features associations of elements to natural sources, hybrid (natural and anthropogenic) and industrial areas.

 

How to cite: Salazar, N., Abbaszade, G., Tserendorj, D., Völgyesi, P., Zacháry, D., Szabó, K., and Szabó, C.: Contamination assessment of heavy metals in urban soil of former industrial city (Ózd, Hungary), EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-16203, https://doi.org/10.5194/egusphere-egu21-16203, 2021.

Organochlorine pesticides (OCPs)
15:50–15:52
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EGU21-5739
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ECS
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Highlight
Annalise Guarino, Antonio Aruta, Pooria Ebrahimi, Salvatore Dominech, Annamaria Lima, Benedetto De Vivo, Shihua Qi, and Stefano Albanese

Organochlorine pesticides (OCPs) are a group of synthetic molecules, consisting of organic structures containing at least one aromatic ring and one covalently bound chlorine atom, widely used for decades in agriculture (as insecticides and fungicides) and, subordinately, in the medical field.

The study area, corresponding to the Acerra-Marigliano conurbation, is located in the middle sector of the Campania Plain, a wide coastal belt roughly extending from the Garigliano River plain, in the northwest of the Campania region, to the Sarno River basin, southward of the volcanic complex of Mt. Somma-Vesuvius. Most of the study area is occupied by agricultural activities (crops, orchards and vineyard) and, subordinately, by industrial settlements and urbanized areas. A total of 33 surficial composite soil samples were collected across the study area, with an average density of 1 sample per 4 sqkm, to be analyzed for their OCPs content.

Compared to other synthetic organic pesticides, OCPs show greater environmental persistence and are generally characterized by a marked tendency towards bioaccumulation and biomagnification along trophic chains due to their lipophilic character. The covalent bond between carbon and chlorine in OCP molecules is very stable and resistant to microbial degradation, but some organisms and plants, together with some physical factors (including pH, solar radiation and humidity), can encourage their metabolic degradation.

The best-known OCP is certainly the dichloro-diphenyl-trichloroethane (DDT), which is one the OCPs defined as Persistent Organic Pollutants by the Stockholm Convention (2001), synthesized since 1873 and used as an insecticide and pesticide since the 1940s. DDT has been, and still is, used to combat malaria in some sensitive areas, such as Africa, India and South America, but its use has been banned in Italy since 1978. DDT can undergo degradation processes, including volatilization or photolysis, whose products are dichloro-diphenyl-dichloroethane and dichloro-diphenyl-dichloroethylene (DDD and DDE, respectively), two compounds with similar properties and, above all, highly persistent. The USEPA (2015) has classified DDT and its metabolites as probably carcinogenic substances for humans, also responsible for damage to the liver, reproductive system and nervous system.

This study aimed at investigating the local distribution, possible sources and contamination levels of DDT isomers and metabolites in the soils of the study area. In particular, we considered six compounds: p,p′-DDT; o,p′-DDT; p,p′-DDD; o,p′-DDD; p,p′-DDE and o,p′-DDE. Concentration of ΣDDTs (i.e. the sum of the six compounds) ranges from a minimum of 4.13 ng/g to a maximum of 734.75 ng/g.

The Italian decree 46/2019 establishes a guideline value for DDE, DDD and DDT concentrations in agricultural soils of 10 ng/g. This value is largely exceeded in the whole study area as regards p,p′-DDT and p,p′-DDE, for which the average concentration resulted equal to 70.37 ng/g and 75.94 ng/g, respectively.

O,p′-DDD and o,p′-DDE show very low concentrations throughout the study area with average concentrations of 1.44 ng/g and 0.75 ng/g, respectively; o,p′-DDT (mean = 5.67 ng/g) and p,p′-DDD (mean = 6.24 ng/g) overcome the guideline mostly in soils collected in the surrounding areas of the towns of Acerra, Brusciano and Marigliano.

How to cite: Guarino, A., Aruta, A., Ebrahimi, P., Dominech, S., Lima, A., De Vivo, B., Qi, S., and Albanese, S.: Organochlorine pesticides in the soils of the Acerra plain: concentration and distribution of DDT isomers and metabolites, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-5739, https://doi.org/10.5194/egusphere-egu21-5739, 2021.

Soil pollution indexes
15:52–15:54
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EGU21-9663
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ECS
Teresa Albuquerque, Carlos Boente, José Luís R. Gallego, Juan José Egozcue, and Vera Pawlowsky

When considering complex scenarios, such as in environmental characterization, where a multiset of attributes must be considered, a dimensional reduction of the problem is mandatory for a clear apprehension of the reality. Maps, broadly mentioned in the literature, are great for spatial pattern visualization of pollutant’s concentration distribution, or to assign areas of contamination enrichment, either if natural or triggered by anthropogenic activities. In the present study, a set of 15 Potentially Toxic Elements - PTEs - (As, Ba, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Sb, Se, Tl, V, and Zn) were analyzed in soils gathered in the Langreo area (80 Km2) —Asturias, Spain— and used (a) to analyze how high concentrations in PTEs are spatially distributed and (b) to explore dissemination trends and the definition of clusters of relative enrichment. To quantify soil pollution, it is important to understand what is meant by pollution-free soil. Often, this background, or pollution baseline, is undefined or only partially known. Given that the concentration of chemical elements is compositional, as the attributes vary together, our approach is based on compositional principles. Finding a balance of pollutant (numerator) over non-pollutant (denominator) elements, aiming sparsity and simplicity as properties, is the key issue for the construction of a Compositional Pollution Index, and two approaches have been explored: (1) taking into account the whole observed composition, and (2) taking into account only a subcomposition, based on expert knowledge, in which the reported elements are: Na, K, Ca, Al, Mg, Fe, Cu, Pb, Zn, As, Sb, Hg. In all tested cases, Sb, Pb, and Hg appear in the numerator of the balance, and K, Al, and Zn in the denominator. A conclusion could be that the overall pollution in the Langreo region is dominated by the content of Sb, Pb, and Hg, relative to the content of K, Al, and Zn. Finally, both indexes went through a stochastic sequential Gaussian simulation. The spatial characterization allowed a broad discussion about not only the concentrations’ spatial distribution and associated uncertainty, but also a better understanding of the possibility of trends of relative enrichment and insight in PTEs fate.

How to cite: Albuquerque, T., Boente, C., R. Gallego, J. L., Egozcue, J. J., and Pawlowsky, V.: Soil pollution indexes through the assessment of a compositional baseline - the Langreo case study, Spain, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9663, https://doi.org/10.5194/egusphere-egu21-9663, 2021.

Field sampling procedure in Italy
15:54–15:56
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EGU21-9952
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ECS
Piero Manna, Giuliano Langella, Simona Vingiani, and Fabio Terribile

Assessment of soil spatial variability is a debated crucial matter in the context of agriculture and environmental management, such as precision agriculture, land erosion and contaminated sites. In rural and industrial areas, the natural complex spatial variability of soil properties (mainly due to changing pedogenetic factors) is further complicated by anthropogenic activities related to soil management (such as deep plowing, sloping vineyards, etc.) or land contamination. Above all, natural and anthropogenic processes considerably overlap in industrial sites or areas affected by illegal waste dumping, where several times type/quantity and especially localization of contaminants are unknown. Proper investigation tools, as much as possible providing rapid, unexpensive and reliable data on soil properties and characteristics, are increasingly requested to scientific community for both the assessment of contamination geography and the soil sampling strategies. Then, focusing on soil sampling of contaminated sites in Europe, the procedure is currently performed according to national regulations, in terms of number, location, type and depth of sampling points.  The Italian regulation (Decree 471/99 - Annex 2) provides a sampling scheme in which the number of observations is commensurated to the geographical extent of the contaminated site. However, data obtained by some Italian surveyed sites, in which a denser sampling scheme was applied, evidenced that observations planned by the regulation were too low and unexpected “hot spots” were not adequately identified. For sure, contamination can frequently follow a very complex site-specific geospatial distribution. Hence, since number, location, type and depth of sampling points has very strong consequences in terms of public safety and costs of characterisation and remediation of contaminated sites, it is a key issue to set up the best strategies for ameliorating field sampling to achieve a proper understanding of the geospatial distribution of soil contamination.

How to cite: Manna, P., Langella, G., Vingiani, S., and Terribile, F.: Soil Spatial Variability in contaminated sites: field sampling procedure in Italy, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-9952, https://doi.org/10.5194/egusphere-egu21-9952, 2021.

Heavy metal in a landfill site
15:56–15:58
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EGU21-10599
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ECS
Thatthep Pongritsakda, Sanya Sirivithayapakorn, Toshikazu Shiratori, and Takeshi Komai

Reducing health risks has been a concern for decades due to anthropogenic activities, especially agricultural, industrial, and landfills. Hazardous pollution can spread to the environment by various routes (surface soil, raw water, groundwater, etc.). However, the behavior of natural elements needs to be concerned in terms of potential sources of pollution, and many countries face high levels of heavy metal problems in surface soils and groundwater. This study focuses on both anthropogenic activity and the presence of natural heavy metals to investigate the actual sources of pollution within the site. The landfill is located at Chachonsao, Thailand, where industrial waste such as industrial dust, sludge, and cement has accumulated, and surface soil and shallow groundwater sample analysis shows that most soil samples have high concentrations of arsenic that exceed global healthy soil standards (30 mg/kg). And shallow groundwater samples have been shown to contain high concentrations of arsenic that exceed the WHO global drinking water standard (0.01 mg/L). High levels of arsenic in surface soils can be interpreted as not only in the area of ​​the site but also in the surroundings where this contaminated situation can be interpreted as being caused by the presence of natural heavy metals. Thus, we investigated and analyzed further details at this site to clarify the risk level of heavy metals and also the effect of the natural source of arsenic.

How to cite: Pongritsakda, T., Sirivithayapakorn, S., Shiratori, T., and Komai, T.: Analysis of potential sources with heavy metals in a landfill site using preliminary data, A case study in Thailand, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10599, https://doi.org/10.5194/egusphere-egu21-10599, 2021.

Transport phenomenon of pollutants in soil column
15:58–16:00
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EGU21-13731
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ECS
Kyouhei Tsuchida, Kengo Nakamura, Monami Kondo, Noriaki Watanabe, and Takeshi Komai

The transport phenomenon of pollutants in soil is complicated because of the formation of the flow path in soil. In this study, the relationship between the flow path in the soil and the elution behavior of various components was evaluated by the column tests with different filling methods to change the flow path in the column. The flow path in the column was visualized by using potassium iodide aqueous solution and X-ray CT. Our result shows that the elution behavior of the easily eluted components was not significantly affected by the flow path in the column. In addition, the cation more eluted when the flow path spread throughout the column than when the flow path was intensive. This suggests that eluted components may be affected by anions in soil. From these results, it was found that the elution behavior of components is influenced by the flow path in the column and some were not, and when it was influenced, the degree of influence is different depending on the components.

How to cite: Tsuchida, K., Nakamura, K., Kondo, M., Watanabe, N., and Komai, T.: Relationship between the formation of flow paths and elution behavior with water flow through the soil column, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13731, https://doi.org/10.5194/egusphere-egu21-13731, 2021.

Arsenic awareness index
16:00–16:02
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EGU21-2485
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ECS
Debasish Mishra, Bhabani S. Das, and Manoj Menon

High levels of arsenic in drinking water and food materials continue to pose a global health challenge. Over 127 million people alone in Bangladesh (BD) and West Bengal (WB) state of India are exposed to elevated levels of arsenic in drinking water. Despite decades of research and outreach, arsenic awareness in communities continues to be low. Specifically, very few studies have reported arsenic awareness among low-income farming communities. A comprehensive approach to assess arsenic awareness, hence, is a key step in identifying research and development priorities so that appropriate stakeholder engagement may be designed to tackle arsenic menace. In this study, we developed a 12-point comprehensive arsenic awareness index (CAAI) and identified key awareness drivers (KADs) associated with CAAI using hybrid feature selection for analysing the responses from the survey conducted in arsenic-affected areas of WB and BD. The two questionnaire surveys comprised of 73 questions each, covering the health, water and community, and food related aspect of arsenic contamination. Comparison of CAAIs showed that the BD farmers were generally more arsenic-aware (CAAI = 7.7) than WB farmers (CAAI = 6.8). Interestingly, the reverse was true for the awareness linked to arsenic in the food chain. Application of hybrid feature selection identified 15 KADs, which included factors related to stakeholder interventions and cropping practices. Inclusion of Boruta wrapper in the hybrid feature selection aided in discarding the randomly associated chi-square (χ2) significant variables (p < 0.05), which included the commonly perceived socio-economic factors such as age, gender and income. An inter-comparison of KADs revealed the differences in objectives and importance laid on various interventions under different government regimes for tackling arsenic menace. Hence, the CAAI and KADs combination revealed a contrasting arsenic awareness between the two farming communities, albeit their cultural similarities. For analysing the predictive power of the KADs for CAAI, both linear and non-linear machine learning models were deployed. Among ML algorithms, classification and regression trees and single C5.0 tree could estimate CAAIs with an average accuracy of 84%. Both communities agreed on policy changes on water testing and clean water supply, while there was less importance laid by both farming communities in testing food for arsenic concentration. Specifically, our study shows the need for increasing awareness of risks through the food chain in BD, whereas awareness campaigns should be strengthened to raise overall awareness in WB possibly through media channels as deemed effective in BD. Overall, this study addresses the UN sustainable development goals (SDGs) such as clean water and sanitation (SDG6), zero hunger (SDG2), good health and well-being (SDG3), and echoes with the WHO’s comprehensive action plan of involving water testing, awareness-building campaigns, and mitigation options to combat arsenic toxicity menace. 

How to cite: Mishra, D., Das, B. S., and Menon, M.: Hybrid feature selection and machine learning approaches for assessing the arsenic awareness of local farming communities in Bengal Basin, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-2485, https://doi.org/10.5194/egusphere-egu21-2485, 2021.

Multiscale approach
16:02–16:04
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EGU21-1585
Simona Vingiani, Paola Adamo, Diana Agrelli, Antonio Giandonato Caporale, Roberto De Mascellis, Giuliano Langella, Florindo Antonio Mileti, and Fabio Terribile

In the framework of both characterization plan and sustainable land reclamation, required by the European regulation for contaminated sites, it is fundamental to detail and understand soil processes involved in the dynamics of environmental contamination. Areas affected by potentially toxic elements (PTE) frequently show wide variability of contaminant distribution both in space and in depth. Targeted sampling is meant to reduce the risk of incorrect hazard evaluation, as well as decrease time and cost of this tricky procedure. Therefore, a pedology based multi-scale approach has been tuned and applied to an industrial area inside an automobile-battery recycling plant (operative since 1970) in South of Italy. Field scale investigation, after data fusion of geophysical (EMI), spectrometric (Gamma ray dose rate and XRF elemental content) and penetrometric (cone index data by ultrasonic penetrometer) parameters, enabled to identify 4 main key zones characterized by different intensity of the measured variables. At pedon scale, 6 soil profiles were dug until 2 m of depth in the identified zones and showed presence of massive/no structured soils (thickness ranging from 25 to 85 cm) in which the total Pb content ranged from 1700 and 12000 mg/kg (field measurements by portable XRF). At optical microscopy scale, many discrete particles (larger than 2 mm of diameter), having angular - subangular shape and different color, were identified and preliminary examined by portable XRF spectrometer for a semi-quantitative analysis, in collimator mode, to detect the most PTE enriched fragments; the results showed the presence of several medium (from 0.5 x 1 mm wide), greyish-black particles enriched of S and/or Cl, of some other bigger (1 x 4 mm), very dense (i.e., not porous), anisotropic (black) fragments characterized by higher content of S, Pb, Cl, As and Sn, as a whole incorporated in a mineral matrix  lesser enriched of S (11 g/kg), Cl (0.8 g/kg), Pb (0.6 g/kg), As (0.2 g/kg). Detailed analysis at submicroscopic scale with SEM, equipped with EDXRA for quantitative analyses, enabled to discriminate the biggest particles in sub-particles mainly composed of Pb (87-89%) and others combining Pb (72-75%) with Cd (11%) and Sn (11-12%). At molecular scale, the mobility and bioavailability of the most abundant PTE were assessed by standardized single-step (ultrapure water, 1M NH4NO3 and 0.05M EDTA) and sequential (EU-BCR and Wenzel)analytical procedures. Although the extent of Cd contamination was much lower than that of Pb, Cd was more mobile and bioavailable than Pb, mainly due to its different geochemical properties. As well, the bioavailability of Sb in the soil was greater than that of As (anionic contaminants).

How to cite: Vingiani, S., Adamo, P., Agrelli, D., Caporale, A. G., De Mascellis, R., Langella, G., Mileti, F. A., and Terribile, F.: Assessment of PTE fate in contaminated soils: pedology based approach from the field to the microscopy scale, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-1585, https://doi.org/10.5194/egusphere-egu21-1585, 2021.

Circular model for waste management
16:04–16:06
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EGU21-10414
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ECS
|
Highlight
Camilo Andres Vargas Terranova, Javier Rodrigo Ilarri, María Elena Rodrigo Clavero, and Paula Andrea Bustos Castro

PROPOSAL OF A CIRCULAR MODEL FOR THE MANAGEMENT OF USABLE WASTE IN LOW-INCOME MUNICIPALITIES IN COLOMBIA

 Camilo-A. Vargas-Terranova 1, Javier Rodrigo-Ilarri 2, María-Elena Rodrigo-Clavero 2, Paula-A. Bustos-Castro3

1  Programa de Ingeniería Ambiental y Sanitaria, Universidad de La Salle, Carrera 2 # 10-70, Piso 6-Bloque A, 111711, Bogotá, Colombia; cvterranova@unisalle.edu.co

2   Universitat Politècnica de València (UPV), 46022 Valencia, Spain; jrodrigo@upv.es; marodcla@upv.es

3   Quipus Consultores SAS, Carrera 8 # 16-36, 250010, Cota, Colombia; paula288bc@gmail.com

 

Waste reuse is a main activity included in the Municipal Solid Waste (MSW) system in Colombia. However, the economic costs related with these activities are not usually included within the service fee. Therefore, operators who perform reuse activities are not formalized or legally constituted and they do not always find a significant economic benefit. This on-going research raises a proposal for a circular model for usable waste in order to add value to the different stages that make up the recovery activity, generating social and environmental benefits.

The circular economy model for the reuse of waste has five phases: i) solid waste generation; ii) solid waste collection; iii) classification of solid waste in collection centers; iv) delivery to an external manager and v) reinstatement to the production chain, to finally return to the first stage.

The financial analysis of the circular economy model is also divided into five phases. In the first phase a basic calculation is made as a reference on the cost of the operation of the public cleaning service, the staff payment cost, the operation of the vehicle fleet and the cost of final waste disposal. In the second and third phases, two scenarios are raised regarding the state of the collection center in a municipality. Specifically, in the second phase, the scenario of a municipality that does not have a collection center or classification and utilization station is proposed. The investment in locating, adapting and building a collection center with different sizes is calculated. In the third phase, a scenario is proposed where a municipality already has a collection center, so the investment for its operation is calculated.

In the fourth phase, the scenarios proposed with the reference value are evaluated. Also, the behavior of production of usable waste and the fluctuation of values in the purchase and sale of this waste in low-income municipalities are determined.

Finally, in the fifth phase, a synthesis of the economic valuation is made, evaluating the scenarios for the municipalities, determining the amount of income and expenses.

How to cite: Vargas Terranova, C. A., Rodrigo Ilarri, J., Rodrigo Clavero, M. E., and Bustos Castro, P. A.: Proposal of a circular model for the management of usable waste in low-income municipalities in Colombia, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10414, https://doi.org/10.5194/egusphere-egu21-10414, 2021.

Circular economy and environmental rehabilitation
16:06–16:08
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EGU21-15508
Erika Santos and Diego Arán

Although at different features and intensities, both abandoned and active mines as well as other industrial areas associated to mining activity, have several environmental problems associated to extreme physicochemical characteristics of their materials, wastes and/or leachates. The conventional closure systems do not contribute to the improvement of the chemical characteristics of some contaminated materials and its leachates. Moreover, superficial layer of soil applied in the conventional closure systems have very high cost of implementation and, especially, maintenance since this is periodically fertilized with organic amendments and re-sown.  

Nowadays, the strategies and technologies for tailings and deposits closure should be based on sustainability and the circular economy. In this context, an effective solution is the use of Technosols derived of wastes and designed specifically for each contaminated/degraded materials in order to remediate, at integrated level, the different components of the ecosystem and reconverting non-productive and degraded areas. The development and in situ application of designed Technosols to growth of highmountain pastures was carried out, firstly, under controlled conditions to evaluate the physic-chemical quality of the designed Technosols and then under field conditions. After superficial application of the Technosol on tailing deposit containing sulfide-rich wastes, plant cover was monitored for one year. The efficiency of Technosol in the improvement of chemical characteristics of mine wastes located under it was evaluated. Technosol was also evaluated in order to confirm the maintenance of its properties and characteristics.

Even in the highmountain conditions, a rapid germination, development and coverage of the surface by herbaceous species was obtained. In three months, there was less than 35% of bare soil. The percentage of bare soil decreased over time and in six months plant cover reached more than 85 % and a height of 65 cm. The productivity of the pasture was between 3 and 9 kg/m2. Plants did not show visible signs of phytotoxicity or nutritional deficiency and elements concentrations in shoots were in normal range, considering plants species in general.  Pasture does not seem to represent an environmental risk for domestic animals that exist in the areas adjacent. The chemical characteristics and andic and eutrophic properties of the Tecnosol were maintained. The Tecnosol stimulated the functionality of the microorganisms-soil-plant system, as well as the alteration of chemical characteristic and microbiological communities of the deposit.

Acknowledgment: This research was supported by Portuguese funds, through Fundação para a Ciência e Tecnologia, within the scope of the project UID/AGR/04129/2020.

How to cite: Santos, E. and Arán, D.: Linking circular economy and environmental rehabilitation in the designed Technosols for highmountain pastures implementation, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-15508, https://doi.org/10.5194/egusphere-egu21-15508, 2021.

Biochar effect on remediation
16:08–16:10
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EGU21-602
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Highlight
José María De la Rosa, Paloma Campos, Ana Z. Miller, Marta Velasco-Molina, Águeda Sánchez-Martín, Araceli De la Rosa, and Heike Knicker

Trace elements are toxic at high concentrations and present long-term persistency in the environment. Biochar, the solid carbonaceous residue produced by pyrolysis of biomass, has been proven to have great potential to adsorb trace elements [1]. Biochar efficiency for trace element adsorption depends on biochar properties, which are affected by feedstock and pyrolysis conditions [2, 3]. Nevertheless, the effect of biochar ageing on trace element immobilization is still not well understood. To fill this gap, a 2-years field experiment was performed next to the Guadiamar River (SW Spain), which was polluted in 1998 due to the breakage of a mining waste pond, causing the dumping of millions of tonnes of toxic sludge. Consequently, the soils studied have acid pH and high concentrations of trace elements (As, Ba, Cu, Pb and Zn). For this experiment, the soils were amended with 8 t ha-1 of rice husk and olive pit biochars. Additionally, biochars produced from rice husk, olive pit and wood chips were buried in these polluted soils using permeable bags. After 2 years, soil and biochar properties as well as trace element contents (total and extractable) were determined. The ageing process reduced the aryl C signal in biochar samples as revealed by cross polarization magic angle spinning 13C nuclear magnetic resonance (CPMAS NMR) analysis. O-containing groups in aged biochar were detected by Fourier Transform mid-Infrared Spectroscopy (FT-IR). Although biochars effectively adsorbed trace elements from the polluted soils, the contents of CaCl2-extracted trace elements in the soils were not modified. This is probably due to the extremely high total abundance of trace elements in these soils, which permit a quick remobilization of bound metals refilling of the extractable pool, and replacing the heavy metals adsorbed by biochar. Consequently, the content of extractable trace elements in these polluted soils may only be reduced by a periodic application of high amounts of biochars.

References:

[1] Amin, M.T., Alazba, A.A., Shafiq, M., 2018. Chem. Eng. J. Arab. J. Sci. Eng. 43, 5711-5722.

[2] Campos, P., De la Rosa, J.M., 2020. Sustainability 12, 6025.

[3] Campos, P., Miller, A.Z., Knicker, H., Costa-Pereira, M.F., Merino, A., De la Rosa, J.M., 2020. Waste Manag. 105, 256-267.

Acknowledgements: The former Spanish Ministry of Economy, Industry and Competitiveness (MINEICO), AEI/FEDER and CSIC are thanked for funding the project CGL2016-76498-R. J.M. De la Rosa acknowledges MINEICO for funding his “Ramón y Cajal” contract. P. Campos thanks “Fundación Tatiana Pérez de Guzmán el Bueno” for funding her PhD.

How to cite: De la Rosa, J. M., Campos, P., Miller, A. Z., Velasco-Molina, M., Sánchez-Martín, Á., De la Rosa, A., and Knicker, H.: Effects of biochar ageing on the remediation potential of trace-element polluted soils, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-602, https://doi.org/10.5194/egusphere-egu21-602, 2021.

Biochar vs magnesite amendments
16:10–16:12
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EGU21-10240
|
ECS
Diego Baragaño, Daniel Arenas Lago, José Luis R. Gallego, and Rubén Forján Castro

The process of industrial change has resulted in the creation of so-called ‘brownfields’ across Europe, particularly in urban areas, in the industrial sections of cities. The need to recover these brownfields can be linked to the new European Commission program "Zero Wastes", that is, to restore or recondition these areas by applying amendments made with by-products or green elements. In this sense, the capacities of magnesite and biochar, inorganic and organic soil amendments respectively, were tested to reduce metal availability and improve the properties of a soil severely contaminated by Cu, Cd, Pb and Zn. To this end, two implementation steps were performed.

First, 1 kg pots containing the polluted soil were amended with either magnesite or biochar and then determined metal availability and soil properties at days 15 and 75 in a greenhouse experiment. In addition, to evaluate the impact of the two treatments on plant growth, the experimental trials were carried out using Brassica juncea L. and compost addition. Both amendments, but particularly magnesite, markedly decreased metal availability. Soil properties were also improved, as revealed by increases in the cation exchangeable capacity. However, plant growth was inhibited by magnesite amendment. This effect was probably due to an increase in soil pH, cation exchange capacity and a high Mg concentration. In contrast, biochar increased biomass production whereas decreased the content of metals harvested. Then, a field scale experiment was performed in situ by means of treating 1 ton of the soil with the magnesite and also with the biochar. Brassica juncea L. was used for testing the impact on plants, and the experiment was monitored at 3, 30 and 60 days from the beginning of the experiment. Similar results to the greenhouse experiment were obtained.

In conclusion, the results indicate that magnesite amendment may be suitable for stabilizing contaminated soils (or even spoil heaps) where revegetation is not a priority. In contrast, although biochar has a lower, but still significant, capacity to immobilize metals, its use emerges as a promising tool for restoring soil properties and thus favoring plant growth.

Acknowledgment

This work was supported by the research projects NANOBIOWASH CTM2016-75894-P (AEI/FEDER, UE) and NANOCAREM MCI-20-PID2019-106939GB-I00 (AEI/FEDER, UE).

Diego Baragaño obtained a grant from the “Formación del Profesorado Universitario” program, financed by the “Ministerio de Educación, Cultura y Deporte de España”.

Arenas-Lago D. thanks to his postdoc contract ED481D 2019/007 (Xunta de Galicia and Universidade de Vigo).

How to cite: Baragaño, D., Arenas Lago, D., R. Gallego, J. L., and Forján Castro, R.: Biochar vs magnesite amendments for metals immobilization: lab-scale and field experiments, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10240, https://doi.org/10.5194/egusphere-egu21-10240, 2021.

Valorisation of cost-effective wastes
16:12–16:14
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EGU21-6811
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ECS
Ana Cortinhas, Teresa C. Ferreira, Ana D. Caperta, and Maria Manuela Abreu

Salinization is one of the major causes of soil degradation and salt-affected soils have been underused due to their physical and chemical properties. Although most conventional crops are non-salt tolerant plants (glycophytes), halophytes can develop under high salinity concentrations and provide food, fodder and other uses, such as remediation and pharmaceuticals. Among them, Suaeda vera can be used for human consumption as forage and in phytoremediation. This study aims to optimize the cultivation of this species by producing a Technosol (TEC) using wastes as amendments to improve the properties of a Fluvisol (FLU). The amendments were constituted by cost-effective wastes: sludge and waste kieselguhr from breweries, medium sand, gravel limestone and biomass obtained from pruning. The FLU used in a microcosm assay was collected in the Tagus Estuary, close to Lisbon, Portugal. The soils properties, plants growth in Fluvisol and Technosol under the estuarine water (Ew) irrigation also collected in Tagus Estuary, were assessed. The microcosm assay was set up with four replicates and the substrata were incubated at 70% of the maximum water-holding capacity for 28 days, in the dark. After, seedlings obtained by germination in wet filter paper with deionised water were transplanted. The amendments, the FLU and the TEC were analysed for: pH, electrical conductivity (EC), concentrations of Corganic, Pextractable, Kextractable and Ntotal. The chemical characteristics of Ew were also analysed for pH, EC, Cl, HCO₃, Na, Ca, Mg, and the SAR was calculated. The plant growth parameters like stem length and biomass were determined. The FLU was slightly alkaline (pH 8), with a high EC (5.6 mS/cm) and low values of Corganic (20 g/kg), Ntotal (1.7 g/kg), Pextractable (1x10-3 g/kg) and Kextractable (0.9 g/kg). Due to the wastes’ properties, the TEC showed a significant increase in Corganic (28 g/kg), Ntotal (2.5 g/kg), P and Kextractable (0.1 and 1.2 g/kg, respectively), in comparison with the FLU. The Ew was strongly saline (EC 22.1 mS/cm), had a neutral pH (7.78) and high concentration of Cl- (7330 mg/L), HCO₃- (267 mg/L), Na+ (4305 mg/L), Ca2+ (210 mg/L) and Mg2+ (538 mg/L). The Ew SAR value was high (157) but tolerated by halophytes. The individuals grown in the TEC presented a larger stem (18 cm) and a higher fresh biomass value (23 g) than individuals grown in the FLU. These results indicate that the wastes improved the Fluvisol properties being S. vera cultivation favoured if carried out in TEC. In a circular economy perspective, this study reveals that it is possible to cultivate a halophyte species with economic potential from underused resources as saline soils, wastes and brackish water.

How to cite: Cortinhas, A., Ferreira, T. C., Caperta, A. D., and Abreu, M. M.: Valorisation of cost-effective wastes and underused soils through Technosols construction for the Suaeda vera Forssk. ex J. F. Gmel. cultivation: a valued marine halophyte, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-6811, https://doi.org/10.5194/egusphere-egu21-6811, 2021.

Wastes for acidic mine water remediation
16:14–16:16
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EGU21-7093
|
ECS
Antonio Aguilar Garrido, Francisco Javier Martínez Garzón, Mario Paniagua López, Manuel Sierra Aragón, Emilia Fernández Ondoño, and Francisco José Martín Peinado

Mining is a crucial industry worldwide because of its economic and social importance. However, the increasing number of operating mines raises major concerns for health and the environment. The intense mining activity generates large quantities of wastes associated with several environmental problems. For example, the generation of acid mine drainages (AMD) by oxidation of sulphide ores stored in tailings deposits, leachates high concentrations of potentially harmful elements (PHEs), which poses severe pollution problems to the environment (aquatic and terrestrial ecosystems). This study evaluates the acid neutralisation capacity and the removal effectiveness of inorganic PHEs present in an AMD of different waste materials. This study is a first approach to future studies to develop pilot remediation studies using designed waste-derived Technosols. The waste used includes 4 mining wastes (iron oxide and hydroxide sludges [IO], marble cutting and polishing sludge [MS], gypsum spoil [GS], and carbonated waste from a peat extraction [CW]), 3 urban wastes (composted sewage sludge [WS], bio-stabilised material from municipal solid waste [BM], and vermicompost from pruning and gardening [VC]), and 3 agro-industrial wastes (2 solid olive-mill by-products [OW, OL] and composted greenhouse waste [GW]). All waste materials were spiked with the acidic water (AMDL) prepared in the laboratory from the oxidation of pyritic tailings from the Aznalcóllar mine accident (1998). Afterward, they were stirred for 24 h and filtered, separating the waste (solid phase) from the leachate (liquid phase). In the leachate (AMDL treated), pH(L) 1:5, EC(L) 1:5, and inorganic PHEs concentrations were measured, the latter by ICP-MS. The acidic water showed a strongly acidic character (pH(L) ~ 2.89), high salinity (EC(L) ~ 3.76 dS m-1), and high concentrations of PHEs. Among them, As, Cd, Cr, Cu, Ni, Pb, Sb, Th, Tl, U, V, Y, and Zn stood out since they far exceed various legal limits widely used worldwide and/or because their high toxicity to humans, animals, plants or microorganisms. The most abundant were Zn (32.21 mg l-1), Cu (6.24 mg l-1), As (2.86 mg l-1), Sb (0.82 mg l-1), Pb (0.60 mg l-1), and Cd (0.45 mg l-1). All wastes were effective in neutralising the acidic pH(L) of the AMD, as the leachates showed pH(L) close to 7. In contrast, changes in the EC(L) have been very irregular among the wastes used. In general, all wastes have been effective in adsorbing the PHEs. Inorganic wastes have been much more effective than organic ones, with adsorption efficiencies above 95% for many of the PHEs (particularly for those in higher concentrations). The waste with the best remediation behaviour were IO, CW, MS, GS, and VC. Conversely, GW and WS were the worst at removing PHEs present in AMD. Therefore, this study shows that many of wastes tested are suitable for the construction of Technosols from these wastes to prevent soil pollution by AMD discharge.

How to cite: Aguilar Garrido, A., Martínez Garzón, F. J., Paniagua López, M., Sierra Aragón, M., Fernández Ondoño, E., and Martín Peinado, F. J.: Potential of mining, agro-industrial, and urban wastes for the remediation of acidic mine water, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-7093, https://doi.org/10.5194/egusphere-egu21-7093, 2021.

Microalgae for Arsenic removal from rice
16:16–16:18
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EGU21-10178
|
Highlight
Cristiane Ottoni, Patrícia Vidigal, Maria Manuela Abreu, Glória Esquível, Isabel Sousa, and António Brito

The presence of As in soil and water can be considered a global threat that can potentially contaminate the food chain. Thus, the remediation of these resources and the decrease of As concentration is a major research goal, especially in rice that tends to accumulate As in the grain. Arsenic uptake by plant species depends on As concentration in the available fraction of the soil and speciation. Several agronomic strategies have been tested to decrease As concentration in rice grain. These include water management, nutrient management and biological approaches among others. In this context, microalgae is known to be effective in the uptake and metabolize of potentially toxic elements like As, which is a cost-effective approach compared to other agronomic strategies. However, in the view of the the current global panorama of growing respect for environmental preservation and focus on energy generation from renewable resources (including domestic and industrial waste products), the use of Microbial Fuel Cells (MFC) has been gaining increased attention. The MFCs have enormous potential as they simultaneously promote the treatment of different types of waste and generate electricity. This is possible due to the conversion of the chemical energy available in the biodegradable substrates directly into electricity, through the catalytic action of electrogenic bacteria attached to the anodic electrode. We aim to develop and establish a protocol for biodegradation of As, captured by microalgae grown in paddy rice fields, in compounds less harmful to the environment and at the same time generating electricity in a continuous process. For this purpose, a selection will be made of cathodic-algae, different electrodes and membrane materials, as well as the operating conditions of MFC. The results monitored are chemical oxygen demand, nitrogen, phosphorus, pH, and production of electricity. At the end, we will be able to evaluate the possibility of decreasing rice As uptake by microalgae that will serve as a raw material for the production of electricity. This will contribute both to help achieve the new European Green Deal policy framework linked with the UN 17 Sustainable Development Goals for 2030, by promoting a resource-efficient and competitive agri-economy while guarantying the health and well-being of citizens from environment-related risks and impacts, covering the “farm to fork” food value chain.

How to cite: Ottoni, C., Vidigal, P., Abreu, M. M., Esquível, G., Sousa, I., and Brito, A.: From rice-microalgae As removal to electricity generation using a microbial fuel cell: a new conceptual approach for the agro-industrial sector, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10178, https://doi.org/10.5194/egusphere-egu21-10178, 2021.

Hydroxyapatite nanoparticles for soil remediation
16:18–16:20
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EGU21-10595
|
ECS
Daniel Arenas Lago, Ruben Forján Castro, Erika S Santos, Diego Arán, and Manuel Arias Estévez

Cadmium is a metal distributed in low concentrations in the environment without biological function, but it can be toxic at high concentration for plants, animals, and/or humans. This element is one of the major soil pollutant, with high mobility and availability under the conditions of many agricultural soils. The use of nanoremediation techniques can be an effective solution for the in situ recovery of contaminated soils with Cd, although the existing information about the consequences of using nanoparticles in soils is still very scarce. In this context. Hydroxyapatite nanoparticles can be an effective amendment for remediation of soils. Quinoa (Chenopodium quinoa Will) is a seed-producing crop that has been cultivated in the Andes for several thousand years but with a good adaptation to different climatic conditions. Currently, quinoa is an emerging multipurpose crop in other parts of the world, due to its high nutritional potential for both human food and animal feedstock and a good alternative to cereals, leading to significant demand and, consequently, cultivation. In this study, we investigated the capacity of hydroxyapatite nanoparticles for recovering artificially contaminated soils with Cd where grown quinoa. For this, seeds of C. quinoa were sown in two different soil (Arenosol and Anthrosol) artificially contaminated with Cd2+ (0; 5, 25 and 50 mg kg-1) and amended or not with 1% (w/w) of hydroxyapatite nanoparticles. The pot assay was carried out under controlled conditions and in a greenhouse for three months. Initial soils were characterized physicochemically and at the end of the assay multielemental concentrations were determined in soil (total and available fraction and plants (shoots). Germination rate, shoot height and dry biomass were measured, as well as pigments, glutathione, ascorbate and H2O2 contents were analysed in plant shoots in order to evaluate plant development and their physiological status. In parallel, a sequential chemical extraction was carried out to determine the Cd distribution in the different geochemical soil phases. Preliminary results indicated that hydroxyapatite nanoparticles have a high capacity to retain Cd. These nanoparticles seem to favour C. quinoa growth even with the highest concentration of Cd added. Therefore, this study will serve as a basis for further scientific research on the potential use of hydroxyapatite in agriculture soils with different characteristics and Cd problems for secure C. quinoa cultivation.

Acknowledgements

This research and postdoc contract from Arenas-Lago D. was supported by the project ED481D 2019/007 (Xunta de Galicia), and Portuguese funds through Fundação para a Ciência e Tecnologia within the scope of the project UID/AGR/04129/2020 (LEAF).

How to cite: Arenas Lago, D., Forján Castro, R., Santos, E. S., Arán, D., and Arias Estévez, M.: Use of hydroxyapatite to reduce Cd pollution in agriculture soils for Chenopodium quinoa cultivation, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-10595, https://doi.org/10.5194/egusphere-egu21-10595, 2021.

Indicator-based proposal for MSW management
16:20–16:22
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EGU21-12084
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ECS
María-Luisa Carnero Pousa, Javier Rodrigo-Ilarri, and María-Elena Rodrigo-Clavero

Municipal Solid Waste (MSW) management activities are important tasks of both national and local governments, as they can induce significant impacts on the environment, the economy and the living quality of the population involved.

The optimal design of a MSW management plan depends greatly on the waste production values and its distribution over the territory, among others. For the optimal design of a MSW system the use of indicators is proposed. Indicators are defined as "the numerical expression, of non-dimensional character, obtained from the fusion of several environmental variables by means of specifically defined weighting criteria". In the scientific literature several proposals about indicators that are focused only on operational aspects of MSW management activities (collection, street cleaning, etc.) are found. Only a decade ago, some indicator groups have begun to emerge in different countries. Such indicators include, in addition to the operational context, social, economic or environmental aspects related to waste management.

The objective of the work has been to make a choice and proposal of a set of social, economic and environmental indicators related to waste management activities, which will allow the analysis of integrated management systems of solid urban waste, considering all the implications that the operations of production, collection, transport, separation, recovery and disposal of the waste suppose from the economic, social and environmental perspectives.

How to cite: Carnero Pousa, M.-L., Rodrigo-Ilarri, J., and Rodrigo-Clavero, M.-E.: Indicator-based proposal for the analysis of Municipal Solid Waste management systems , EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-12084, https://doi.org/10.5194/egusphere-egu21-12084, 2021.

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