Fabrication of a novel and highly selective ion-imprinted PES-based porous adsorber membrane for the removal of mercury(II) from water

Abstract Herein, poly(ether sulfone) based ion imprinted membranes (IIM) were prepared through phase inversion, using ion imprinted polymer (IIP) particles obtained by radical copolymerization of acrylamide, acrylonitrile and ethyleneglycoldimethacrylate along with a template of Hg(II) complexed with bathophenanthroline (BPh). Optimization of the ability for Hg(II) removal from water and pure water flux of the IIM were investigated through Central Composite Design (CCD) combined with Response Surface Methodology (RSM). Accordingly, the optimized factors were obtained as IIP percentage of 2.5 wt% used in membrane preparation, as well as trans-membrane pressure of 0.19 bar, pH 7.95 and Hg(II) concentration of 4 ppm during filtration through the membrane. Using the optimum parameters, the removal percentage and flux of IIM were about 98.1% and 37.5 kg/m2 h, respectively. The maximum adsorption capacity of IIM was 432 mg/m2 (or 21.6 mg/g), almost four times higher than that of non-imprinted membrane (NIM; 105 mg/m2) (or 5.25 mg/g) which was prepared using copolymer particles prepared without the Hg(II) template. The IIM showed a high selectivity toward Hg(II) ions compared to other metal ions and could be effectively recycled for at least 6 times without any major loss of adsorption capacity. The synthesized imprinted membranes have demonstrated considerable potentials to selectively separate mercury(II) from simulated industrial wastewater.