Revitalisation of metal-contaminated, EDTA-washed soil by addition of unpolluted soil, compost and biochar: Effects on soil enzyme activity, microbial community composition and abundance

Effect of soil washing with biodegradable chelators on the toxicity of residual metals and soil biological properties

“…In contrast, washing with these chelating agents increased the MBC concentrations by 14-40% in the treated soils, indicating the presence of residual chelators (Beiyuan et al, 2017b). Stringent conditions during soil washing induced the disaggregation of loosely bound soil structures, which presumably caused lysis of microbial cells and release of enzymes (Kaurin et al, 2018). Therefore, our results imply that special attention should be paid to replenishment of N and P to ensure the quality of remediated soil after washing with biodegradable chelators.…”

“…The physiochemical characteristics of the restored soil inevitably changed upon removal of metals during the remediation process, thus influencing the soil microbial activity (Udovic and Lestan, 2012;Chae et al, 2017). Soil enzyme activities and microbial biomass are considered to be bio-indicators because of their rapid response and sensitivity to early soil environmental changes caused by remediation with soil washing (Im et al, 2015;Yoo et al, 2016;Chae et al, 2017;Kaurin et al, 2018). In the present study, soil washing with biodegradable chelators induced significant adverse effects on soil microorganisms (P b 0.05), resulting in suppressed biological responses (Table 2).…”

Feasibility of Chinese cabbage (Brassica bara) and lettuce (Lactuca sativa) cultivation in heavily metals−contaminated soil after washing with biodegradable chelators

“…Phytoremediation experiments have also demonstrated that the application of EDTA could severely hinder the plant growth, because of the increased essential metal dissolution or, through its interference with cellular structures and/ or functions (Luo et al, 2018). More effective revitalization approaches, such as amendment with biochar, are therefore clearly required to reÀestablish and restore the nutrient pool to washed soil to allow the soils to be used as fertile plant substrates (Beiyuan et al, 2018;Kaurin et al, 2018;Yoo et al, 2018).…”

“…Decreasing pollutant concentrations is a crucial remediation objective, but attention should also be paid to reestablishing a healthy ecosystem capable of supporting fauna, flora, and microbes to ensure the treated soil is safe and can be sustainably reused (Guo et al, 2016;Jelusic and Lestan, 2015). Soil washing processes may adversely affect the activities of soil enzymes such as dehydrogenase (Im et al, 2015), acid phosphatase (Im et al, 2015;Wang et al, 2018), arylsulfatase (Yi and Sung, 2015), beglucosidase (Chae et al, 2017;Kaurin et al, 2018), and urease (Chae et al, 2017). These enzymes play critical roles in organic matter turnover and nutrient cycling in soil (Im et al, 2015;Kaurin et al, 2018).…”

“…Soil washing processes may adversely affect the activities of soil enzymes such as dehydrogenase (Im et al, 2015), acid phosphatase (Im et al, 2015;Wang et al, 2018), arylsulfatase (Yi and Sung, 2015), beglucosidase (Chae et al, 2017;Kaurin et al, 2018), and urease (Chae et al, 2017). These enzymes play critical roles in organic matter turnover and nutrient cycling in soil (Im et al, 2015;Kaurin et al, 2018). Soil washing can also simultaneously solubilize mineral elements (i.e., Ca, Mg, Al, and Fe) with the removal of metals (Wang et al, 2017;Yip et al, 2010).…”