The aim of the doctoral dissertation was to contribute to a better understanding of soil washing technology using the chelate ligand EDTA, to investigate the effects of EDTA on soil and the environment in a broader sense, and to determine whether this technology can be considered a green and sustainable solution for the remediation of soil contaminated with potentially toxic elements. By adding zero-valent iron to the soil during the remediation process, we prevented the emission of residues of EDTA chelates with toxic elements from the soil as early as 6 days after the remediation of pH-neutral carbonate soils and 7 days after the remediation of acidic soils. We investigated the impact of soil remediation on herbicide degradation as an important function of agricultural soil. Using the FOMC model, we determined the DT50 value for individual herbicides. In acidic soils, DT50 increased by 16% with isporoturon, 21% with bentazone, 42% with mecoprop-P and 111% with S-metolachlor. In carbonate soils, the DT50 value of remediation soils for mecoprop-P increased by 3%, while it decreased by up to 30% for the other three herbicides. However, the DT50 was always lower than the average value published in the literature. In addition, the efficacy and safety of EDTA was compared with the efficacy and safety of biodegradable chelate ligands GLDA, EDDS, and IDS. A quantitative analysis, in which we used eight different remediation-relevant categories, showed the order of suitability: EDTA> GLDA> IDS> EDDS. The remediated soil allowed a similar growth of buckwheat (F. esculentum) and an even better growth of Chinese cabbage (B. rapa) compared to the original soil. The activity of the stress enzymes of the antioxidant prevention system in Chinese cabbage and the physical properties of the soil were similar in the remediated and original soils. Similarly, soil function was assessed by measuring microbial respiration and the activity of soil enzymes involved in the circulation of C, N, and P in soil. Soils remediated with EDTA performed better compared to soils remediated with biodegradable chelate ligands. The effects of remediation on soil and plants: buckwheat, spinach, radicchio, lamb`s lettuce, lettuce, garlic, onion, leek, carrot, and kohlrabi were also examined under realistic conditions in a demonstration garden with 9 raised beds, each with 1.75 t of air-dry soil. Despite the fact that the soil had an above-average contamination before the remediation (Pb 1854, Zn 3833 and Cd 21 mg kg–1), we succeeded in reducing the Pb concentration in most plants, with the exception of buckwheat and carrots, to below the legal limit. Cd concentrations in most plants were below or near the legal limit in most plants, only carrots, spinach, and chicory exceeded the limits. Remediation with EDTA reduced the Pb, Zn, and Cd contents in soil by 71, 28, and 53%, respectively, but had no significant effect on soil properties and function.
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