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
燕文明 1李皋翔 1陈红 2颜秉龙 3陈翔 4何翔宇 1李琪 1傅聪玮 1邵一纯1
作者信息
- 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
- 折叠
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.
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 CaO2with 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.
关键词
锁磷剂/增氧剂/砷/协同吸附作用/去除机制Key words
lanthanum modified bentonite/oxygenating agent/arsenic/synergistic adsorption/removal mechanism引用本文复制引用
基金项目
国家重点研发计划(2022YFC3202601)
国家自然科学基金(41971047)
江苏省高等学校大学生创新创业训练计划(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(2023491611)
出版年
2024
国家科技期刊平台
NSTL
万方数据