【摘要】 为研究锁磷剂（LMB）与增氧剂CaO₂联合应用对富营养化湖泊沉积物中砷（As）污染的去除效果，理清联用技术对沉积物-水界面As的去除机制，以太湖梅梁湾底泥为研究对象开展模拟试验。结果表明：LMB与CaO₂联用对沉积物中的As的去除效果优于LMB、CaO₂单独使用；在试验第45天，LMB与CaO₂联用对沉积物溶解态As去除率最大，为39.31%,在试验第90天，LMB与CaO₂联用对As的去除效果较差；为实现沉积物中As的高效去除，可在加入LMB和CaO₂45 d后对LMB和CaO₂进行回收；LMB与CaO₂联用去除As的主要机制为LMB和CaO₂中的La³⁺、Ca²⁺与砷酸根离子络合形成LaAsO₄和Ca₃（AsO₄）₂沉淀以及Fe（Ⅲ）、Mn（Ⅳ）氧化物的协同吸附作用；Fe和Mn氧化还原在控制沉积物As的释放中起着关键作用。更多还原

【Abstract】 In order to study the removal effect of lanthanum modified bentonite（LMB） and oxygenating agent CaO₂ on arsenic（As） pollution in the sediment of eutrophic lakes, and clarify the removal mechanism of combined technology on the sediment-water interface, a simulation test was carried out on the sediment of Meiliang Bay in Taihu Lake. The results show that the combined use of LMB and CaO₂ has a better removal effect on As in sediment than the use of LMB and CaO₂ alone. On the 45th day of the experiment, the maximum removal rate of dissolved As in sediment by the combination of LMB and CaO₂ was 39.31%. On the 90th day of the experiment, the combined use of LMB and CaO₂ showed poor removal efficiency for As. To achieve efficient removal of As in sediment, LMB and CaO₂ can be recovered after 45 days of adding covering agents. The main mechanism of As removal by the combination of LMB and CaO₂ is the complexation of La³⁺and Ca²⁺in LMB and CaO₂ with arsenate ions to form LaAsO₄ and Ca₃（AsO₄） ₂ precipitates, as well as the synergistic adsorption of Fe（Ⅲ） and Mn（Ⅳ） oxides. The redox cycling of Fe and Mn plays a crucial role in controlling the release of As from sediment.更多还原