摘要
通过直接观察三种重金属离子(Pb^(2+)、Cu^(2+)和Zn^(2+))溶液分别与螯合型表面活性剂C_(12)-ED3A3Na溶液相互滴定以及C_(12)-ED3A3Na溶液溶解难溶性重金属盐[CaCO3和(PbCO3)2Pb(OH)2]或氧化物(PbO、ZnO和CuO)的实验现象变化,发现C_(12)-ED3A3Na溶液滴定重金属离子溶液过程中溶液经历由澄清到浑浊再到澄清的变化,大部分难溶金属盐和氧化物在一定时间内可完全溶解于C_(12)-ED3A3Na溶液.表明C_(12)-ED3A3Na去除土壤或水体重金属的机理为:C_(12)-ED3A3Na单体首先与游离的可溶性重金属离子生成难溶性螯合物,难溶性螯合物随即增溶于C_(12)-ED3A3Na胶束中,这样就促使难溶性的重金属盐(碱或氧化物)发生化学转化和(或)溶解成可溶性重金属离子,可溶性重金属离子又与C_(12)-ED3A3Na单体结合成难溶性螯合物,后者再增溶C_(12)-ED3A3Na胶束中,这样各种形态的重金属就会不断被去除;另外,三种重金属离子与C_(12)-ED3A3Na生成的螯合物的红外图谱表明C_(12)-ED3A3Na中的羟基参与了配位反应;用测试电导率来确定螯合剂与金属离子的络合比的方法还有待完善.
The changes in the mutual titration of three heavy metal ions(Pb^2+,Cu^2+ and Zn^2+)with the chelating surfactant C12-ED3A3Na solution and in the dissolution of insoluble heavy metal salts or oxides by C12-ED3A3Na solution were directly observed,respectively.The results showed that the solution of C12-ED3A3Na solution titrating heavy metal ions was changed from clarification to turbidity to clarification,and most of the insoluble metal salts and oxides can be completely dissolved in C12-ED3A3Na solution for a certain time.The removal mechanism of heavy metals in soil or water by C12-ED3A3Na is suggested that the C12-ED3A3Na monomer first reacts with the free soluble heavy metal ions to insoluble chelates.The insoluble chelates are then solubilized in the C12-ED3A3Na micelles,so that the insoluble heavy metal salts(alkali or oxide)are chemically converted and(or)dissolved into soluble heavy metal ions;the soluble heavy metal ions are combined with C12-ED3A3Na monomer to form insoluble chelates,which are solubilized in C12-ED3A3Na micelles.In this way,various forms of heavy metals are removed.In addition,the infrared spectra of the chelates produced by the reaction of three heavy metal ions with C12-ED3A3Na indicated that the hydroxyl group in C12-ED3A3Na participated in the coordination reaction;the method of determining the complexation ratio between chelating agents and metal ions by testing electrical conductivity needs to be improved.
作者
彭忠利
陈鸿雁
王春花
PENG Zhongli;CHEN Hongyan;WANG Chunhua(School of Chemistry and Materials Engineering,Huizhou University,Huizhou 516007,Guangdong,China)
出处
《惠州学院学报》
2018年第6期1-6,共6页
Journal of Huizhou University
基金
国家自然科学基金(21276102)
广东省自然科学基金(2015A030313677)
惠州学院校级大学生创新创业实验项目(CX2018073)
