分散支撑液膜体系中Pb^(2+)离子的传输

Study on Transportation of Pb(Ⅱ) by Dispersion Supported Liquid Membrane System

在现有支撑液膜分离技术的理论研究基础上,探索合适的液膜分离体系,研究了Pb(Ⅱ)在PC-88A-煤油-HCl分散支撑液膜体系中的传输行为;考察了料液pH值、膜溶液与解析剂体积比、解析相中HCl浓度以及Pb(Ⅱ)的起始浓度对Pb(Ⅱ)传输的影响。结果表明,以HCl为解析剂,料液相pH=5.25、膜溶液与解析剂体积比为160∶40、解析相中HCl浓度为5.00 mol/L时,该分散支撑液膜体系对金属Pb(Ⅱ)具有良好的传输作用。在选取的最佳传输条件下,料液相中Pb(Ⅱ)的初始浓度为3.00×10-4mol/L时,传输190 min,传输率可达88.9%,而传统支撑液膜只有72.3%。分散支撑液膜不仅具有较高的传输效率,而且膜体系稳定,膜的使用寿命长。

Supported liquid membrane separation processes have recently received considerable attention due to characteristics such as fast mass transfer,high selectivity and separation efficiency,lower operation costs and no secondary pollution.They are particularly suitable for the separation and enrichment of heavy metal ions.However,supported liquid membrane separation processes are limited in large-scale industrial applications due to membrane instability and short membrane life.The transportation and separation of Pb（Ⅱ） through a PC-88A-kerosene-HCl dispersion supported liquid membrane（DSLM）,based on the theoretical study of the existing supported liquid membrane（SLM） separation technology,is reported.The effects of pH value in the feed phase,volume ratio of liquid membrane phase and hydrochloric acid,concentrations of HCl in the strip phase and initial concentration of Pb（Ⅱ） in the feed phase are also studied.The results show that lead ion can be transported effectively when pH=5.25 in the feed phase,the volume ratio is 160∶40,concentrations of HCl in the strip phase is 5.00 mol/L.The transport rate of Pb（Ⅱ） can reach to 88.9% through DSLM,and 72.3% through traditional SLM,respectively,under the optimum condition,and the transport time is 190 min for initial concentration of 3.00×10-4 mol/L Pb（Ⅱ）.It shows that DSLM has a high transmission efficiency in comparison with conventional SLM.At the same time,the system can improve the stability of the membrane and extend the life of the membrane.