The finite resource of fertile soil can take thousands of years to develop. Non-degradable toxic metals (heavy metals), pose a significant health risk due to their persistence in the environment. Soil washing with EDTA (ethylenediaminetetraacetic acid) has been shown to remove toxic metals (Pb, Zn, Cd), but this process can also have a significant impact on soil microbial diversity. In this study, we investigated, using molecular methods (18S rRNA amplicon sequencing), the development of the arbuscular mycorrhizal (AM) fungal communities in the roots of Lolium perenne after a soil remediation treatment with EDTA. Plants were grown on two soil types (calcareous and acidic), in remediated and control (unremediated, polluted) soils, and with or without the addition of a local environmental inoculant (grassland soil and roots). The addition of the inoculant increased the richness and evenness of AM fungi, and reduced the compositional dissimilarity of communities between remediated and unremediated soils. Disturbance from the remediation process and inoculation, lead to a shift in the identity of dominant taxa reflecting different traits among the AM fungi. This suggested two main mechanisms behind community development in remediated soils, i.e. priority effects and competitive exclusion among dominant taxa. These findings emphasise the importance of nature-based solutions (indigenous environmental inoculants) and AM fungi for sustainable soil management practices. This is particularly important for restoring soil biodiversity in sites that have been exposed to multiple disturbances, which may include contaminated sites and soil remediation, as well as conventional agricultural systems, and urban soils.

Heavy metals (HM) are among the most important pollutants in soils worldwide. Soil washing with ethylenediaminetetraacetate (EDTA) is an effective method for removing Pb, Zn, and Cd from contaminated soil. This study evaluated the impact of EDTA remediation on N-cycling microbial community through a mesocosm experiment. Remediated and untreated (original) soils with varying HM levels were studied, including two heavily contaminated soils from Austria and Slovenia differing in pH, and additionally non-contaminated soil (CONT) with low natural geogenic HM concentrations. Influence of plant addition (Lolium perenne) and soil inoculum (grassland rhizosphere) on soil microbial community was examined in combination with remediation. EDTA remediation significantly reduced soil Pb, Cd, and Zn content. However, the process led to a decline in microbial community abundances in contaminated soils, especially from the Slovenian site, likely due to the release of high amounts of HM during EDTA washing. In contrast, no such effect was observed in non-contaminated soil. Site specific changes in N cycling gene abundances after EDTA treatment were observed in both contaminated soils. Increase of pH as a result of remediation coincided with increased abundance of bacterial over archaeal ammonia oxidizers. Decreased nosZI/nosZII and (nirK + nirS)/(nosZI + nosZII) ratios in soils after remediation process indicate lower genetic potential for N2O emissions in remediated than original soil while no such shift was observed for control soil. Notably, the addition of soil inoculum negatively impacted microbial community abundance regardless of soil type. Overall, our results highlight that although EDTA remediation poses challenges for microbial survival, combining remediation with plant-based strategies can foster ecosystem recovery and enhance the long-term sustainability of remediated soils.

Sewage sludge is a valuable source of phosphorus but contains toxic metals that hinder its use as fertilizer. We present a novel process that simultaneously stabilises sludge through post-aerobic digestion (12 days, pH 5.8-7.6, solid-to-liquid ratio 1:25 (dry w/v)) and removes toxic metals using ethylenediaminetetraacetate (EDTA, 10 mM). On average, 74.4% of EDTA was successfully recycled by alkalinization of process solution with quicklime (CaO) to pH 12.5 and reused in subsequent batches. Chelator losses were compensated by the addition of Na-EDTA. Toxic metals, along with excess Ca and Na, were effectively removed from the recycled process solution, enabling closed-loop operation without wastewater generation. During five consecutive batches, total solids in the sludge were reduced by an average of 23.2%, and 74, 61, 26, and 43% of Zn, Cu, Cr, and Pb, respectively, were removed. The leaching of residual toxic metals from the stabilised and decontaminated sludge was further reduced by 55-88% through the addition of zero-valent iron (3% dry w/w). The process also increased the phosphorus concentration in the sludge by 15% and improved its phytoavailability up to 1.8-fold (as determined by ammonium-lactate extraction). This process is sustainable: it preserves valuable nutrients, can be integrated into existing wastewater treatment plant operations, generates only 17% solid waste (relative to the dry weight of the sludge), and produces no wastewater. Due to the recycling of costly EDTA, reagent costs were halved, reaching €73 t-1 of dry sludge.

The treatment of sewage sludge (SS) is one of the biggest challenges due to its large output and contamination with toxic metals (TMs). SS is also a potential resource for P, a strategic macronutrient in agriculture. The feasibility of integrated removal of TMs from SS by chelation and washing with ethylenediaminetetraacetate (EDTA) and SS solids reduction by aerobic digestion in bioreactors was investigated. In three consecutive SS treatment batches, an average of 70, 40 and 59% of Zn, Cu and Pb were removed. Cr was not chelated and remained in the SS. EDTA persisted during the aerobic digestion of SS and was efficiently recycled (82% on average) in the pH gradient 12.5- 2 (ReSoil (R) method) and reused in the next batch. The reduction of SS solids (on average 18.4% in 6 days) was more efficient with EDTA than with the control treatment (7.4%). The integrated process also increased the concentration of plant-available P in the washed SS by an average of 1.6-fold compared to the control. EDTA induced fragmentation of SS. This resulted in a loss of SS dry matter (on average 26.1%) and total P (on average 24.6%). The novel integrated process efficiently removed TMs that chelate with EDTA, is scalable and should be compatible with current processes in wastewater treatment plants.

Sewage sludge (SS) is rich in plant nutrients, including P, N, and organic C, but often contains toxic metals (TMs), which hinders its potential use in agriculture. The efficiency of removal of TMs by washing with ethylenediamine tetraacetate (EDTA), in combination with hydrodynamic cavitation (HC) and the usability of washed sewage sludge as fertilizer were investigated. The environmental risk was assessed. During 8 wash batches an average 35, 68, 47 and 45 % of Pb, Zn, Cd and Cu, respectively, as well as 22 and 5 % Mn and Fe were removed from the SS. The process solutions and EDTA were recycled at a pH gradient of 12.5 -2, which was achieved by adding quicklime (CaO) and then acidification by H 2 SO 4 , so that no wastewater was produced, only solid waste (ReSoil (R) method). The quality of the recycled process solutions (they remained unsaturated with salts) and the efficiency of the washing process were maintained across all batches. On average, 46 % of the EDTA was lost during the process and was replenished. The initial leachability of EDTA-mobilized Pb, Zn, Cu, Cr and Fe remaining in the washed SS increased 6-, 17-, 3-, 11- and 11 -fold, respectively, but not to hazardous levels except for Zn. After washing, P and K remained in the SS, plant -available P increased 3.3 -fold, while total N and C were reduced by 20.28 and 2.44 %, respectively. Washed SS was used as fertilizer in the pot experiment. The yield of Brassica juncea did not improve, the uptake of TMs by the plants and the leaching of TMs from the soil were minimal. Our study highlighted the drawbacks and potential feasibility of the new SS washing method.

Contamination with toxic metals prevents the use of sewage sludge (SS) as a soil fertilizer. Hydrodynamic cavitation, thermal microwaving, microwave-assisted alkaline, and acid hydrolysis coupled with ethylenediaminetetraacetate (EDTA) washing were tested as a method to remove toxic metals from SS. Acid hydrolysis coupled with EDTA washing was most effective and was used in a closed-loop process based on ReSoil technology. EDTA and process solutions were recycled at a pH gradient of 12.5–2, which was imposed by the addition of quicklime (CaO) and H2SO4. An average of 78%-Pb, 76%-Zn, 1%-Cu, and 17%-Cr were removed from SS in five consecutive batches. No wastewater was generated, only solid waste (40%). The EDTA lost in the process (42%) was resupplied in each batch. In a series of batches, the process solutions retained metal removal efficiency and quality. The treatment removed 70% and 23% of P and N, respectively, from SS and increased the leachability of Zn, Cu, Mn, and Fe in the washed SS by 11.7, 6.8, 1.4, and 5.2 times, respectively. Acid hydrolysis coupled with EDTA washing proved to be a technically feasible, closed-loop process but needs further development to reduce reagent, material, and nutrient loss and to reduce toxic emissions from the washed sludge.

Sewage sludge has the potential to be used as a fertilizer in agriculture because of its high nutritional value, but it is often contaminated with toxic metals (TM). This study investigated whether ReSoil® technology, based on the use of EDTA (50, 70, and 100 mmol l-1), efficiently removes TM from sewage sludge collected after aerobic (blato1) and anaerobic (blato2) treatment. The highest removal efficiency of Pb was achieved in blato1 (up to 60 %) and of Zn and Cu in blato2 (up to 55 and 29 %, respectively). The content of nutrients did not change significantly after remediation, only available phosphorus decreased up to 1.7-times in blato2, but its content remained high (489-510 mg 100-1 g-1). After remediation, the concentration of all metals, except Zn, in the leachates was below the limit for non-hazardous substances. To demonstrate the possibility of recycling process solutions and EDTA, blato2 was washed in 5 consecutive batches with 50 mmol l-1 washing solution, removing on average 28 % Pb, 48 % Zn, 35 % Cu, 30 % Mn, and 10 % Fe. ReSoil® technology removes metals from sludge and preserves its nutritional value. However, the efficiency of the technology depends on the treatment process used in the wastewater treatment plant.

Sewage sludge (SS) is a potential resource for P and other nutrients, but often contaminated with metals. SS containing Pb-102, Zn-968, Cu-267, Cr-101, Mn-222, and Fe-8374 mg kg(-1) was washed in a batch process for 1 h with a recycled washing solution containing 50 mmol L-1 of recycled EDTA and 50 mmol L-1 H2SO4, solid/liquid ratio 1/7 (w/V). After solid/liquid separation, the washed SS was further rinsed 3-times with cleansed recycled solutions. EDTA and process solutions were recycled/cleansed in a pH gradient of 12.5-2.0 imposed by addition of CaO and H2SO4 (the ReSoiI (R) method). EDTA, recycled as ineffective Ca-EDTA, was activated by capturing Ca with H2SO4. The process was closed-looped, no wastewater was generated, solid waste was centrifuged away. 10 consecutive SS washing batches preserved the quality of the process solutions. Metals were mainly removed from the SS organic fraction, the average removal was Pb-35, Zn-59, Cu-60, Cr-19, Mn-25, and Fe-1%. Washing reduced the leachability of Cu and Cr from SS by 13.4 and 3.5 times, but increased the leachability of Ph, Zn, Mn, and Fe by 2.5, 3.8, 1.9, and 1.6 times, respectively. Metal concentrations in the leachates were below the limits stipulated as hazardous. The content of accessible P and K in washed SS decreased by 24 and 45%, and the total N decreased by 10%. Overall, the results prove the feasibility of the novel SS washing process.

Odpadno blato iz čistilnih naprav (ČN) ima zaradi velike hranilne vrednosti potencial za uporabo v kmetijstvu, vendar je pogosto onesnaženo s potencialno strupenimi kovinami (PSK). V raziskavi smo preverili ali ReSoil® tehnologija, ki temelji na uporabi EDTA (50, 70 in 100 mmol l-1), omogoča učinkovito odstranjevanje PSK iz odpadnega blata, vzetega po aerobni (blato1) in anaerobni (blato2) biološki obdelavi. Največji delež odstranitve Pb smo dosegli v blatu1 (do 60 %), največji delež odstranitve Zn in Cu pa v blatu2 (do 55 in 29 %). Vsebnost hranil se po remediaciji ni bistveno spremenila, le vsebnost dostopnega fosforja se je v blatu2 po remediaciji do 1,7-krat zmanjšala, vendar je še vedno ostala velika (489-510 mg 100-1 g-1). Po remediaciji so bile koncentracije v izpirkih za vse kovine, razen za Zn, pod mejo za nenevarne snovi. Za dokazovanje možnosti recikliranja procesnih raztopin in EDTA smo blato2 oprali s 50 mmol l-1 pralno raztopino v seriji 5 zaporednih remediacij in pri tem v povprečju odstranili 28 % Pb, 48 % Zn, 35 % Cu, 30 % Mn in 10 % Fe. ReSoil® tehnologija sicer omogoča odstranjevanje PSK iz blata in pri tem ohrani njegovo hranilno vrednost, vendar je učinkovitost tehnologije odvisna od postopkov obdelave blata na ČN.

In this study, we investigated the importance of plant cover for secondary succession and soil fungal community development in remediated substrates after EDTA washing of metal-contaminated soils. The abundance of the total fungal community, determined by ITS fungal marker genes (Internal Transcribed Spacer region), and root colonisation by arbuscular mycorrhizal (AM) fungi were monitored in two types of soil material (calcareous and acidic) sown with perennial ryegrass (Lolium perenne L.) and without plant cover (bulk soil). Four months after the start of the experiment, the abundance of ITS genes in the soil clearly showed that the presence of plants was the main factor affecting the total fungal community, which increased in the rhizosphere soil in most treatments, while it remained at a low level in the bulk soil (without plants). Interestingly, the addition of environmental inoculum, i.e., rhizosphere soil from a semi-natural meadow, did not have a positive effect on the abundance of the total fungal community. While fungal ITS genes were detected in soils at the end of the first growing season, arbuscular mycorrhizal (AM) structures were scarce in Lolium roots in all treatments throughout the first season. However, in the second season, more than a year after the start of the experiment, AM fungal colonisation was detected in Lolium roots in virtually all treatments, with the frequency of colonised root length ranging from 30% to >75% in some treatments, the latter also in remediated soil. This study demonstrates the importance of plants and rhizosphere in the development and secondary succession of fungal communities in soil, which has important implications for the revitalisation of remediated soils and regenerative agriculture.

Two soils contaminated with potentially toxic metals (PTMs) contrasting in pH and mineralogy were remediated with CaEDTA, and changes in soil organic matter (SOM) composition were investigated. Previous studies showed no significant loss of SOM from CaEDTA-treated soils, but the results of our study reflected significant decreases (from 46 to 49%) in the free fraction of humic acids (HAs). Remediation affected the composition of the free HA fraction via disturbance of intermolecular bonds - an increase in phenolic and aromatic groups with a simultaneous decrease in carbohydrates - which was confirmed by FTIR spectroscopy in both soils. Because non-radical molecules such as carbohydrates were selectively removed, the concentration of free radicals in the free HA fraction increased in acidic soil. The bound fraction of HAs and fulvic acids (FAs) in SOM, which are important due to their stability and the permanent effects they have on the soil's physical properties, remained unchanged in both remediated soils. The effect of soil recultivation was observed only in the excitation emission matrix (EEM) fluorescence spectra of HAs. In terms of SOM, CaEDTA soil washing can be considered moderately conservative; however, the restoration of free humic fractions is likely to be a long-term process.

Soil chemistry of toxic metalloids and metals differs, making their simultaneous removal difficult. Soil contaminated with As, Pb, Zn and Cd was washed with oxalic acid, Na-dithionite and EDTA solution. Toxic elements were removed from the washing solution by alkalinisation with CaO to a pH 12.5: As was co-precipitated with Fe from Fe-EDTA chelate formed after the soil washing. The toxic metals precipitated after substitution of their EDTA chelates with Ca. The novel method was scaled up on the ReSoil (R) platform. On average, 60, 76, 29, and 53% of As, Pb, Zn, and Cd were removed, no wastewater was generated and EDTA was recycled. Addition of zero-valent iron reduced the toxic elements' leachability. Remediation was most effective for As: phytoaccessibility (CaCl2 extraction), mobility (NH4NO3), and accessibility from human gastric and gastrointestinal phases were reduced 22, 104, 6, and 51 times, respectively. Remediation increased pH but had no effect on soil functioning assessed by fluorescein diacetate hydrolysis, dehydrogenase, beta-glucosidase, urease, acid and alkaline phosphatase activities. Brassica napus produced 1.9 times more biomass on remediated soil, accumulated no As and 5.0, 2.6, and 9.0 times less Pb, Zn and Cd, respectively. We demonstrated the novel remediation technology as cost-efficient (material cost = 41.86 (sic) t(-1)) and sustainable.

In this study, we evaluated the impact of washing of Pb, Zn and Cd contaminated soil using EDTA-based technology (ReSoil®) on soil biological properties by measuring some of the most commonly used/sensitive biological indicators of soil perturbation. We estimated the temporal dynamics of the soil respiration, the activities of soil enzymes (dehydrogenase, β-glucosidase, urease, acid and alkaline phosphatase), and the effect of the remediation process on arbuscular mycorrhizal (AM) fungi in original (Orig), remediated (Rem) and remediated vitalized (Rem+V) soils during a more than one-year garden experiment. ReSoil® technology initially affected the activity level of soil microbial respiration and all enzyme activities except urease and reduced AM fungal potential in the soil. However, after one year of vegetable cultivation and standard gardening practices, soil microbial respiration, acid and alkaline phosphatase in the Rem and Rem+V reached similar activities as in the Orig. Only the activities of dehydrogenase and β-glucosidase remained lower in the remediated soil compared to the Orig. The frequency of arbuscular mycorrhiza in the root system, arbuscular density in the colonized root fragment, and the intensity of mycorrhizal colonization in the colonized root fragments in the remediated treatments increased with time; at the end of the experiment, no consistent differences in these parameters of mycorrhizal colonization were found among the treatments. Our results suggest a restored biological functioning of the remediated soil after one year of vegetable cultivation. In general, no differences were found between the Rem and Rem+V treatments, indicating that simple common garden practices are sufficient to restore soil functioning after remediation.

In previous reports large-scale EDTA-based soil washing using ReSoil® technology was demonstrated. In the current study, we established a vegetable garden with nine raised beds (4 × 1 × 0.5 m), three with original (contaminated) soil, three with remediated soil, and three with remediated soil vitalized by addition of vermicompost, earthworms, and rhizosphere inoculum. The garden was managed in 6 rotations between July 2018 and November 2019. Buckwheat was sown first as a green manure followed by spinach, lamb's lettuce, chicory, garlic, onion, leek, lettuce, carrot, kohlrabi and spinach again. Buckwheat growth on the remediated soil was reduced by half. Throughout the gardening process there were no remarkable differences in bulk density, hydraulic conductivity, available water capacity, and aggregate stability of the original and remediated soil. Biomass yield and plant performance, as measured by NDVI, also remained similar regardless of soil treatment. Remediation reduced Pb concentration in edible parts of vegetables from 76 (garlic) to 95% (kohlrabi), Zn concentration from 14 (lettuce) to 76% (first cutting of chicory), and Cd concentration from 33% (carrot) to 91% (leek and second cutting of chicory). The transfer of metals from soil to root and from root to shoot occurred in the order: Pb < Zn < Cd. The bioconcentration of toxic metals in edible plant parts was generally lower in the remediated soils. Application of ReSoil® technology and growing vegetables that exclude metals, especially Cd, has potential for safe food production on remediated soils. Vitalization had little effect on the properties of the remediated soil.

The viable chelator-based soil washing has yet to be demonstrated on a larger scale. Soil containing 1850, 3830 and 21 mg kg−1 Pb, Zn and Cd, respectively, was washed with 100 mmol EDTA kg−1 in a series of 16 batches (1 ton soil/batch) using the new ReSoil® technology. The ReSoil® recycled the process water and 85% of the EDTA, producing no wastewater and 14.4 kg ton−1 of waste. The soil washing removed 71, 28 and 53% of Pb, Zn and Cd, respectively, mainly from the carbonate fraction, saturated the soil with basic cations and increased the soil pH by up to 0.5 units. Raised beds (4 × 1 × 0.5 m) with original (contaminated) and remediated soil were constructed as lysmeters, and local produce was grown from July 2018 to November 2019. Throughout the gardening period, the concentration of Pb and Cd in the leachates from the remediated soil was lower and that of Zn was higher than in the original soil. Remediation decreased the concentration of plant-available and mobile toxic metals, as determined by CaCl2 and NH4NO3 extractions, and reduced the bioavailability of Pb, Zn, and Cd in the simulated human gastrointestinal phase by an average of 4.3, 1.7 and 2.7-fold, respectively. Revitalization with vermicompost, earthworms and rhizosphere soil, and spring fertilisation with compost and manure, had no significant effect on the mobility and accessibility of the toxic metals. The ReSoil® is a cost-effective technology (material cost = 18.27 € ton−1 soil) and showed the prospect of sustainable reuse of remediated soil.

In washing soils contaminated with toxic metals, the replacement of recalcitrant EDTA with biodegradable chelators has gained high expectations. Herein we investigated the feasibility of using EDTA and biodegradable GLDA, EDDS and IDS under conditions pertinent to operational remediation technology, in a pilot-scale experiment. GLDA and IDS did not precipitate from process solutions, which lessened their recyclability. In other process parameters, chelator supplement, Na-saturation of process solutions and processing time, EDTA outperformed biodegradable chelators. Treatment with EDTA was also the most effective in total Pb and Zn removal and least impacted soil properties. GLDA was slightly better in Cd removal. EDDS and IDS were inefficient. All chelators effectively removed easily-available Pb, Zn and Cd from the exchangeable soil fraction. EDTA was the most efficient chelator in reducing the bioaccessibility of Pb and GLDA in reducing the bioaccessibility of Cd from simulated human gastrointestinal tract. Treatment with GLDA had an edge in reducing plant bioaccessibility of toxic metals, but induced worrying leachability of Pb. This was 8.3-times higher than with the process with EDTA and 3.4-times higher than in original soil. In general, our results demonstrate the advantage of EDTA over tested biodegradable chelators in process and remediation efficiency and environmental safety.

Soils contaminated with Pb, Zn and Cd are hazardous. Persistent EDTA and biodegradable GLDA, EDDS and IDS have been used as chelators in the ReSoil soil washing technology, which recycles chelator and curbs toxic emissions. The washed soils supported similar growth of buckwheat (F. esculentum) and better growth of Chinese cabbage (B. rapa) compared with the original (not-remediated) soil. The growth of buckwheat on EDDS-washed soil was an exception and was 67% suppressed. The activities of enzymes of the plant antioxidant preventive system were assessed in roots and leaves of Chinese cabbage on all soils. Similar activities were measured, confirming that washed soils are not harmful to the plants. Plant uptake of potentially toxic elements was reduced from all washed soils, i.e. buckwheat grown on GLDA-washed soils accumulated up to 27 and 83 times less Pb and Cd than in the original soil. The initial Pb emissions in leachate from GLDA and IDS washed soils were up to 89 and 92% higher than those of the original soil, respectively. The latter emissions ceased to the levels measured in original, EDTA and EDDS washed soils. Soil physical properties (water holding capacity, aggregate stability) and soil functionality, assessed as soil respiration and activity of enzymes indicative for soil C, N and P cycle, were similar in all soils after 10 weeks of plant growth experiment. The overall results indicate a low impact of the remediation on soil quality. Soils washed with EDTA performed slightly better compared to GLDA-, EDDS- and IDS-washed soils.

The use of EDTA-based soil washing is prevented by chelant environmental persistence and the hazard of toxic post-remedial emissions. Calcareous and acidic soils with 828 and 673 mg Pb kg(-1) , respectively, and co-contaminated with Zn and Cd, were washed with 90 and 60 mM EDTA, respectively, to remove 67 and 80% of Pb. Washed soils were rinsed until 6.5 and 5.1 mM EDTA, respectively, was measured in the final rinsing solutions. Emissions of residual EDTA and chelated metals from remediated soils were mitigated by adsorption on zero-valent Fe (ZVI), which was added (0.5-1.5%, w/w) to the slurry of washed soil immediately before rinsing. ZVI addition prevented the initial post-remedial surge of toxic metals leachability and minimised toxic emissions from calcareous and acidic soil as soon as 6 and 7 days after remediation, respectively. The extractability/leachability of EDTA and toxic metals from remediated and ZVI amended soils diminished to close to emissions from the original soils, frequently below the limit of quantification by flame-AAS, and was not affected by the pH of the leaching solutions. Efficient curbing of toxic post-remediation emissions as demonstrated herein is of paramount importance for recognition of EDTA-based remediation as environmentally safe. (C) 2018 Elsevier Ltd. All rights reserved.

The ability of contaminated farmland soils reclaimed by remediation to dissipate pesticides and thus to mitigate their unwanted environmental effects, i.e., leaching and run-off, was studied. Novel EDTA-based soil washing technology (EDTA and process waters recycling; no toxic emissions) removed 79 and 73% of Pb from acidic and calcareous soil with 740 and 2179 mg kg(-1) Pb, respectively. The dissipation kinetics of four herbicides: mecoprop-P, isoproturon, bentazon and S-metolachlor was investigated under field conditions in beds with maize (Zea mays) and barley (Hordeum vulgare). The biphasic First-Order Multi-Compartment (FOMC) model was used to fit experimental data and calculate the herbicides' half-life (DT50) in soil. Remediation significantly (up to 64%) decreased dehydrogenase activity assessed as a marker of soil microbial activity and prolonged the DT50 of herbicides in acidic soils from 16% (isoproturon) to 111% (S-metachlor). Remediation had a less significant effect on herbicide dissipation in calcareous soils; i.e., mecoprop-P DT50 increased by 3%, while isoproturon and S-metachlor DT50 decreased by 29%. Overall, the dissipation from remediated soils was faster than the average DT50 of tested herbicides published in the Pesticides Properties DataBase. Results demonstrate that EDTA-based remediation of the studied soils does not pose any threat of extended herbicide persistence. (C) 2019 Elsevier Ltd. All rights reserved.