Separation of Hg(II) from Its Aqueous Solution Using Bulk Liquid Membrane

Liquid membranes for separation of metal ions from wastewaters

The paper reviews application of various liquid membranes (LM), particularly of emulsion and supported liquid membranes, for metal separation from model and industrial wastewaters. A variety of carriers and separation systems is shown. Not only model solutions on a laboratory scale are presented but also some examples of real wastewater separation with LM are reported.

Supported liquid membrane based removal of lead(II) and cadmium(II) from mixed feed: Conversion to solid waste by precipitation

Simultaneous removal of two heavy metals, lead(II) and cadmium(II), from mixed feed using supported liquid membrane (SLM) based technique is investigated in this work. The carrier-solvent combination of "sodium salt of Di-2-ethylhexylphosphoric acid (D2EHPA) (4% w/w) in environmentally benign coconut oil" was immobilized into the pores of solid polymeric polyvinylidene fluoride (PVDF) support. Sodium carbonate (Na2CO3) was used as the stripping agent. Carbonate salts of lead(II) and cadmium(II) were formed in the stripping side interface and they were insoluble in water leading to precipitation inside the stripping solution. The transportation of solute is positively affected due to the precipitation. Lead(II) removal was found to be preferential due to its favorable electronic configuration. The conversion of the liquid waste to the solid one was added advantage for the final removal of hazardous heavy metals.