摘要
金矿开采会导致河流砷(As)和镉(Cd)的超标,严重影响沉积物环境质量。针对矿区河流(招远界河)沉积物中As和Cd浸提及浸提液中As和Cd的去除,该课题开展了多项探索性研究:通过单一试剂浸提法和组合分步浸提法对其进行浸提,采用中和沉淀和硫化物沉淀法对浸提液中的As和Cd进行去除。结果表明:0.1 mol/L的草酸(OX)单一浸提法对于沉积物中As的浸提效果最优(浸提率接近100%),0.01 mol/L EDTA与0.1 mol/L Na_2S_2O_3组合分步浸提法对于Cd的浸提效果显著(浸提率接近100%);对于As和Cd同步浸提效率较高的2种浸提液,盐酸(HCl)浸提液中As采用中和沉淀法(pH>6)去除效果明显,EDTA-OX浸提液中As采用硫化钠沉淀法(去除时间15 min)去除效果显著,以上2种浸提液中Cd采用中和沉淀和硫化钠沉淀联用法(pH=7,Na_2S=0.05 mol/L)去除效果较好。
High concentrations of As and Cd in sediment are usually related to gold mining. Exploratory studies were done to investigate As and Cd extraction in sediments as well as the removal of As and Cd from the leachate based on the mining area river(Jiehe River) sediments. Both of the heavy metals were extracted using single reagent extraction and sequential chemical extraction and then removed through neutralization and sulfide precipitation. The results show that the single reagent extraction of 0.1 mol/L oxalic acid(OX) and the sequential chemical extraction of 0.01 mol/L EDTA combined 0.1 mol/L Na2S2O3 have the best extraction efficiency for As and Cd(approximately 100%), respectively. Two kinds of solutions that have high simultaneous extraction efficiency with As and Cd are chosen to study the removal efficiency. The results indicate that there is a high removal efficiency for As in the HCl extraction solution using the neutralization precipitation method(pH>6), whereas As removal efficiency in the EDTA-OX extraction is significant through the sulfide precipitation method(reaction time, 15 min). Additionally, Cd in both of the above extraction solutions can be effectively removed using the neutralization precipitation combined the sulfide precipitation(Na2S=0.05 mol/L, pH=7).
作者
王婧
孙瑞川
盛彦清
赵国强
杨剑
WANG Jing;SUN Ruichuan;SHENG Yanqing;ZHAO Guoqiang;YANG Jian(Research Center for Coastal Environment Engineering Technology of Shandong Province,Yantai Institute of Coastal Zone Research,Chinese Academy of Sciences,Yantai 264003,China;University of Chinese Academy of Sciences,Beijing 100049,China;Yantai Environmental Protection Engineering Consulting Design Institute,Yantai 264000,China)
出处
《环境科学与技术》
CAS
CSCD
北大核心
2018年第11期72-80,共9页
Environmental Science & Technology
基金
国家自然基金(41373100)
山东省科技惠民计划(2013kjhm060308)
中科院关键技术人才项目
关键词
沉积物
重金属
界河
化学浸提
化学沉淀法
sediments
heavy metals
Jiehe River
extraction
chemical precipitation process
