Department of Plant Biology and Soil Science, Faculty of Biology, University of Vigo, Vigo, Spain; Environmental and Geochemical Sciences Department, The James Hutton Institute, Craigiebuckler, Aberdeen AB158QH, UK.
Department of Plant Biology and Soil Science, Faculty of Biology, University of Vigo, Vigo, Spain.
J Environ Manage. 2022 Sep 15;318:115530. doi: 10.1016/j.jenvman.2022.115530. Epub 2022 Jun 22.
The remediation of legacy metal(loid) contaminated soils in-situ relies on the addition of [organic] amendments to reduce the mobility and bioavailability of metal(loid)s, improve soil geochemical parameters and restore vegetation growth. Two vermicomposts of food and animal manure waste origin (V and V) were amended to an arsenic (As) and copper (Cu) contaminated mine soil (≤1500 mg kg). Leaching columns and pot experiments evaluated copper and arsenic in soil pore waters, as well as pH, dissolved organic carbon (DOC) and phosphate (PO) concentrations. The uptake of As and Cu to ryegrass was also measured via the pot experiment, whilst recovered biochars from the column leaching test were measured for metal sorption at the termination of leaching. Vermicompost amendment to soil facilitated ryegrass growth which was entirely absent from the untreated soil in the pot test. All amendment combinations raised pore water pH by ∼4 units. Copper concentrations in pore waters from columns and pots showed steep reductions (∼1 mg L), as a result of V & V compared to untreated soil (∼500 mg L). Combined with an increase in DOC and PO, As was mobilised an order of magnitude by V. Biochar furthest reduced Cu in pore waters from the columns to <0.1 mg L, as a result of surface sorption. The results of this study indicate that biochar can restrict the mobility of Cu from a contaminated mine soil after other amendment interventions have been used to promote revegetation. However, the case of As, biochar cannot counter the profound impact of vermicompost on arsenic mobility.
原位修复遗留金属（类）污染土壤依赖于添加[有机]改良剂来降低金属（类）的迁移性和生物可利用性，改善土壤地球化学参数并恢复植被生长。两种源自食物和动物粪便废物的蚯蚓堆肥（V 和 V）被添加到砷（As）和铜（Cu）污染的矿山土壤（≤1500mgkg）中。通过淋溶柱和盆栽实验评估了土壤孔隙水中的铜和砷，以及 pH 值、溶解有机碳（DOC）和磷酸盐（PO）浓度。通过盆栽实验还测量了砷和铜对黑麦草的吸收，而在淋溶试验结束时，从柱淋溶试验中回收的生物炭用于测量金属吸附。蚯蚓堆肥的添加促进了黑麦草的生长，而在盆栽试验中未处理的土壤中完全没有生长。所有改良剂组合都将土壤孔隙水的 pH 值提高了约 4 个单位。与未处理的土壤（约 500mgL）相比，V 和 V 处理使柱和盆栽中铜的浓度在孔隙水中急剧降低（约 1mgL）。DOC 和 PO 的增加相结合，V 使 As 的迁移性提高了一个数量级。生物炭进一步将柱中孔隙水中的 Cu 降低到<0.1mgL，这是由于表面吸附。本研究的结果表明，在使用其他改良剂促进植被恢复后，生物炭可以限制受污染矿山土壤中 Cu 的迁移性。然而，对于 As 而言，生物炭无法抵消蚯蚓堆肥对砷迁移性的深远影响。
