螯合剂对矿山水体底泥中重金属提取效率研究  

Study on the Extraction Efficiency of Heavy Metals from the Bottom Mud of Mine Water Bodies by Chelating Agent

作　　者：孜尔叶克·尼牙孜汗 邹航 成格力 李智鹏 万博 黄永炳[1] NIYAZIHAN Zieryeke;ZOU Hang;CHENG Geli;LI Zhipeng;WAN Bo;HUANG Yongbing(School of Resources and Environmental Engineering,Wuhan University of Technology,Wuhan 430070,China;CCTEG Wuhan Engineering Company,Wuhan 430070,China)

机构地区：[1]武汉理工大学资源与环境工程学院,湖北武汉430070 [2]中煤科工集团武汉设计研究院有限公司,湖北武汉430070

出　　处：《金属矿山》2023年第11期124-129,共6页Metal Mine

基　　金：国家自然科学基金面上项目(编号:42277055)。

摘　　要：为实现矿山水体底泥重金属污染的绿色修复,利用EDTA、GLDA和MGDA等3种螯合剂在不同的条件下提取矿山水体底泥中的重金属Cd、Cu和Ni并分析其作用机理。研究采用分批提取、BCR提取等试验方法比较分析了EDTA、GLDA和MGDA等3种螯合剂和不同影响因素对矿山水体底泥中重金属提取效率的影响。研究结果表明,最佳淋洗时间因重金属元素及螯合剂种类而异,pH是螯合剂提取重金属效率的主要影响因素,螯合剂浓度的增加能显著提高重金属去除率,累计循环淋洗对重金属的去除效率提升不足5%。螯合剂去除矿山水体底泥中重金属是通过改变重金属的存在形态。在室温体系下,3种螯合剂最适使用条件为:EDTA与重金属离子摩尔比6∶1(淋洗时间16 h,pH=4),循环淋洗2次;GLDA与重金属离子摩尔比4∶1(淋洗时间8 h,pH=4),循环淋洗3次;MGDA与重金属离子摩尔比6∶1(淋洗时间8 h,pH=4),循环淋洗3次。在最适使用条件下,螯合剂对Cd的去除效果由大到小依次为EDTA、GLDA、MGDA,对Cu的去除效果由大到小依次为MGDA、EDTA、GLDA,对Ni的去除效果由大到小依次为MGDA、GLDA、EDTA。绿色螯合剂GLDA和MGDA可以替代传统螯合剂EDTA,提高成本效益和环境友好性。用Na_2S处理淋洗液后,重金属回收率可达95%以上,处理后淋洗液中重金属含量低于国家排放标准,可直接排放。研究结果可为螯合剂去除矿山水体重金属污染底泥提供理论支撑。In order to remove the heavy metals in bottom mud of mine water bodies non-pollutionally,three kinds of che-lating agents namely EDTA,GLDA and MGDA,were used to extract heavy metals Cd,Cu and Ni under various conditions,while analyzing their underlying mechanisms.Experimental methods such as batch extraction and BCR extraction were used to compare and analyze the influence of EDTA,GLDA and MGDA,as well as different factors,on the efficiency of heavy metal ex-traction from mine water sediments.The results revealed that the optimal leaching time varied depending on the heavy metal el-ement and the chelating agent used.pH was identified as the primary influencing factor for chelating agent efficiency in heavy metal extraction.Additionally,an increase in chelating agent concentration significantly improved the removal rate of heavy met-als,with cumulative cyclic leaching resulting in a minimal improvement of less than 5%in heavy metal removal efficiency.The chelating agents facilitated the removal of heavy metals from mine water sediments by altering the speciation of heavy metals.Under ambient temperature conditions,the most suitable conditions for the three chelating agents were as follows:for EDTA,leaching time of 16 hours,pH=4,n(EDTA)∶n(HMs)=6∶1,with two cycles of leaching;for GLDA,leaching time of 8 hours,pH=4,n(GLDA)∶n(HMs)=4∶1,with three cycles of leaching;for MGDA,leaching time of 8 hours,pH=4,n(MGDA)∶n(HMs)=6∶1,with three cycles of leaching.Under these optimal conditions,the removal rates for Cd from great to small were in the order EDTA,GLDA and MGDA,for Cu,MGDA,EDTA and GLDA,and for Ni,MGDA,GLDA and EDTA.Green chela-ting agents GLDA and MGDA demonstrated their potential to replace traditional chelating agent EDTA,offering improved cost-effectiveness and environmental friendliness.Following treatment with Na2S,heavy metal recovery rates exceeding 95%were a-chieved,with the heavy metal content in the leachate meeting national discharge standards and thus suitable for direct disposal.The findings

关 键 词：螯合剂 矿山水体底泥 重金属污染 淋洗液回收 

分 类 号：X753[环境科学与工程—环境工程]