A review on emulsion liquid membrane (ELM) for the treatment of various industrial effluent streams

The excessive release of toxic metal ions by the several industrial effluent streams into the environment has imposed a serious threat to the ecological system. Therefore, the removal of these toxic metal ions from the wastewater of various industrial effluent streams has received a considerable amount of interest and also currently becoming an imperative area of research. Since last few decades, ELM based separation processes have been become an attractive and efficient way for the removal of toxic metal ions, organic and inorganic acids, and industrial pollutants of the various aqueous waste effluent streams. ELM is an emerging alternative technique to the conventional solvent extraction processes with an additive advantage of low solvent inventory and energy requirements. Moreover, it also preconcentrates the solute by performing both extraction and stripping operations simultaneously in a single unit. The main aim of this review paper is to elucidate the comprehensive review on the ELM (its pertinent properties/characteristics), its membrane phase compositions, its stability, and its process parameters respectively and also to delineate the applications of this technique for the removal of various low concentrated solutes.