Effect of simulated root exudates on the distribution, bioavailability, and fractionation of potentially toxic elements (PTEs) in various particle size fractions of zinc smelting slag: Implication of direct revegetation.
Effect of simulated root exudates on the distribution, bioavailability, and fractionation of potentially toxic elements (PTEs) in various particle size fractions of zinc smelting slag: Implication of direct revegetation.
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DOI：
10.1016/j.jenvman.2023.118642
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发表时间：
2023-07
影响因子：
8.7
通讯作者：
Youfa Luo;Rongrong Xing;Yonggui Wu
中科院分区：
文献类型：
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作者：
Youfa Luo;Rongrong Xing;Yonggui Wu
直接植被是金属冶炼渣场植物稳定化的一种有前途的策略。在渣场进行直接重新植被时，渣与根系分泌物直接接触。炉渣粒度组分被认为是影响潜在有毒元素（PTE）地球化学行为的关键因素。然而，根系分泌物对不同渣粒级PTE地球化学行为的影响尚不清楚。在这里，模拟多年生黑麦草（多年生黑麦草）根系分泌物直接在锌冶炼渣网站上的分布，生物利用度，和分馏的PTE（铜，铅，锌，镉）在不同的渣粒级的影响进行了研究。结果表明，PTEs主要分布在<1 mm的渣粒中，1 mm渣粒中PTEs的质量负荷最<1 mm slag particles were higher than those in the >大。炉渣中Cu、Zn和Cd的生物有效性随粒度的减小而增加，而Pb的生物有效性随粒度的减小而增加。在根系分泌物的存在下，<0.25和1-2 mm的炉渣颗粒减少，而0.25-0.5、0.5-1和>2 mm的炉渣颗粒增加。根系分泌物促进了酸溶性PTE转化为其他更稳定的馏分在各种渣粒级。根系分泌物增强了与迁移的PTE的渣颗粒的聚集，造成不同渣粒度级的PTE的地球化学行为的差异。这些研究结果有助于了解金属冶炼渣直接植被中PTE的地球化学行为，为指导金属冶炼渣场植被恢复的环境风险管理提供重要依据。
Direct revegetation is a promising strategy for phytostabilization of metal smelting slag sites. Slag comes into direct contact with root exudates when slag sites undergo direct revegetation. The slag particle size fractions are considered the key factor influencing the geochemical behaviour of potentially toxic elements (PTEs). However, the effects of root exudates on the geochemical behaviours of PTEs in various slag particle size fractions remain unclear. Here, the effects of simulated root exudates of perennial ryegrass (Lolium perenne) directly revegetated at a zinc smelting slag site on the distribution, bioavailability, and fractionation of PTEs (Cu, Pb, Zn, and Cd) in various slag particle size fractions were investigated. The results showed that PTEs mainly occurred in the <1 mm slag particles; the mass loads of PTEs in the <1 mm slag particles were higher than those in the >1 mm slag particles. The bioavailability of Cu, Zn, and Cd rather than Pb in the slag increased as the particle size decreased. There was a decrease in the <0.25 and 1–2 mm slag particles and an increase in the 0.25–0.5, 0.5–1, and >2 mm slag particles in the presence of root exudates. Root exudates enhanced the transformation of acid-soluble PTEs into other more stable fractions in various slag particle size fractions. Root exudates enhanced the aggregation of slag particles associated with the migration of PTEs, causing differences in the geochemical behaviour of PTEs in various slag particle size fractions. These findings are beneficial for understanding the geochemical behaviour of PTEs in metal smelting slags undergoing direct revegetation and provide an important basis for the guidance of environmental risk management of the revegetated metal smelting slag sites.