锁磷剂与增氧剂联用去除沉积物中砷的效果与机制  

Effect and mechanism of removing As from sediment by combination of LMB and oxygenating agent

作　　者：燕文明[1] 李皋翔 陈红[2] 颜秉龙 陈翔 何翔宇 李琪[1] 傅聪玮 邵一纯 YAN Wenming;LI Gaoxiang;CHEN Hong;YAN Binglong;CHEN Xiang;HE Xiangyu;LI Qi;FU Congwei;SHAO Yichun(The National Key Laboratory of Water Disaster Prevention,Hohai University,Nanjing 210098,China;Institute of Water Science and Technology,Hohai University,Nanjing 210098,China;Lianyungang Water Resources Planning and Design Institute Co.,Ltd.,Lianyungang 222006,China;Nanjing Institute of Environmental Science,Ministry of Ecology and Environment,Nanjing 210008,China)

机构地区：[1]河海大学水灾害防御全国重点实验室,江苏南京210098 [2]河海大学水科学研究院,江苏南京210098 [3]连云港市水利规划设计院有限公司,江苏连云港222006 [4]生态环境部南京环境科学研究所,江苏南京210008

出　　处：《水资源保护》2024年第3期149-156,共8页Water Resources Protection

基　　金：国家重点研发计划项目(2022YFC3202601);国家自然科学基金项目(41971047);江苏省高等学校大学生创新创业训练计划项目(202110294178Y);水灾害防御全国重点实验室“一带一路”水与可持续发展科技基金项目(2023491611)。

摘　　要：为研究锁磷剂(LMB)与增氧剂CaO_(2)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CaO_(2)联用对沉积物中的As的去除效果优于LMB、CaO_(2)单独使用;在试验第45天,LMB与CaO_(2)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CaO_(2)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CaO_(2)45 d后对LMB和CaO_(2)进行回收;LMB与CaO_(2)联用去除As的主要机制为LMB和CaO_(2)中的La^(3+)、Ca^(2+)与砷酸根离子络合形成LaAsO_(4)和Ca_(3)(AsO_(4))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。In order to study the removal effect of lanthanum modified bentonite(LMB)and oxygenating agent CaO_(2)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 CaO_(2)has a better removal effect on As in sediment than the use of LMB and CaO_(2)alone.On the 45th day of the experiment,the maximum removal rate of dissolved As in sediment by the combination of LMB and CaO_(2)was 39.31%.On the 90th day of the experiment,the combined use of LMB and CaO_(2)showed poor removal efficiency for As.To achieve efficient removal of As in sediment,LMB and CaO_(2)can be recovered after 45 days of adding covering agents.The main mechanism of As removal by the combination of LMB and CaO_(2)is the complexation of La^(3+)and Ca^(2+)in LMB and CaO_(2)with arsenate ions to form LaAsO_(4)and Ca_(3)(AsO_(4))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.

关 键 词：锁磷剂 增氧剂 砷 协同吸附作用 去除机制 

分 类 号：X524[环境科学与工程—环境工程]