Abstract A comprehensive study has been carried out to evaluate the extraction of heavy metals mixture (Co2+, Cr3+, Cu2+, Ni2+) from aqueous media by Winsor II non-ionic microemulsion, containing polyoxyethylene (4) lauryl ether as non-ionic surfactant and butyl acetate as organic phase. The extraction mechanism is based on the formation of thiocyanate complexes of metals and their transfer from aqueous to microemulsion phase, either towards the interfacial film of surfactant (Co2+) or into the core of micelles (Cr3+, Cu2+, Ni2+). The value of the distribution coefficient for Co2+ was higher than for the other studied metals and its extraction efficiency was not dependent on the working conditions, showing a maximum value (99.99%) in all cases. By using successive extractions, chromium, nickel and copper ions that remained in the aqueous phase after first extraction were transported into the microemulsion phase, leading to an increase in the extraction efficiency up to 99.99% for chromium and copper, and 85% for nickel. Based on pH influence, a selective extraction of Co2+ and Cr3+ can be achieved, since the cobalt ions were completely extracted into the microemulsion phase at pH = 1, and the chromium ions still remained in the aqueous phase.

中文翻译：

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硫氰酸根离子和微界面表面的协同作用作为多金属提取的驱动力

摘要 以聚氧乙烯 (4) 月桂基醚为非离子表面活性剂，以聚氧乙烯 (4) 月桂基醚为非离子表面活性剂，采用 Winsor II 非离子微乳液对水性介质中重金属混合物 (Co2+, Cr3+, Cu2+, Ni2+) 的萃取进行综合研究。醋酸盐作为有机相。萃取机制是基于金属硫氰酸盐络合物的形成以及它们从水相转移到微乳液相，或者转移到表面活性剂 (Co2+) 的界面膜或进入胶束核 (Cr3+、Cu2+、Ni2+)。Co2+ 的分配系数值高于其他研究金属，其提取效率不依赖于工作条件，在所有情况下均显示最大值（99.99%）。通过使用连续提取，铬，第一次萃取后留在水相中的镍和铜离子被输送到微乳液相中，导致铬和铜的萃取效率提高到 99.99%，镍的萃取效率提高 85%。基于 pH 的影响，可以实现对 Co2+ 和 Cr3+ 的选择性萃取，因为在 pH = 1 时钴离子被完全萃取到微乳液相中，而铬离子仍保留在水相中。