Efficient Separation and Recovery of Precious Metal Ions by Polymer Inclusion Membranes (PIMs): A Mini Review

Recently, PMs are rare/noble chemical elements used in various industrial areas such as jewelry, oil, gas, petrochemical, electronic, ceramic, glass, pharmaceutical and medical industries so that the recovery of PIMs has become very important due to its low availability in nature and high price. Conventional methods can be shown as the use of microorganisms, the application of biosorption-based processes, the solvent extraction process, adsorption, ion exchange and electrolysis processes. The first system used for the recovery of PMs was the use of algae, bacteria and yeast as microorganisms, then a biosorption-based process, which has high efficiency and low operating costs, and minimizes both the formation of dangerous chemicals and the formation of biological sludge, has been started to be used. However, the method that has been used a lot in recent years is the PIM process. PIMs offer a new alternative for membrane processes due to their advantages. These processes are not only simple in design, easy to operate and environmentally friendly, but also have high stability, good mechanical properties and chemical resistance. In addition, they are thin and flexible compared to other membranes. Studies on the recovery of PM ions by using membranes are briefly presented in this review. Abbreviation: Ammonium chloride NH₄Cl; Polymer inclusion membranes PIMs; Bis (1-butyl pentyl) adipate BBPA;Poly tetra fluoro ethylene PTFE; Bis (2-ethylhexyl) adipate DEHA; Polyvinyl chloride PVC; Bulk Liquid Membranes BLMs; Polyvinyl difluoride PVDF; Calix^[4] pyrrole^[2] thiophene CPY; Potassium Thiocyanate KSCN; Cellulose triacetate CTA; Precious Metals PMs; Dibutyl sebacate DBS; Recovery Factor RF; Dioctyl phthalate DOP; Sodium perchlorate NaClO₄; Emulsion Liquid Membranes ELMs; Sodium Sulfite Na₂SO₃; Hydrochloric acid HCl; Supported Liquid Membranes SLMs; Initial flux J0; Thiocyanate SCN; N-[N, N-di (2-ethylhexyl); Tri iso butyl phosphine sulfide Cyanex471; aminocarbonylmethyl] glycine D2EHAG; Tri octyl (dodecyl) phosphonium chloride P₈₈₈₁₂Cl; Nitrophenyl octyl ether NPOE; Nitrophenyl pentyl ether NPPE; Tri-iso-octylamine TIOA; Platinum Group Metal PGM; Tri-n-octylamine TOA; Poly acryl nitrile PAN; Tri octyl methyl ammonium chloride Aliquat 336; Poly butylene adipate coterephthalate PBAT; Polyether sulfone PES; Tris- (2-ethylhexyl) phosphate TEHP.