A facile ion imprinted synthesis of selective biosorbent for Cu2+ via microfluidic technology

BACKGROUND: Heavy metal pollution has become one of the most serious environmental problems. Novel approaches are needed for removal of heavy metal from water. Copper, a familiar heavy metal, has attracted much attention for its remarkable toxic domino offect at elevated concentrations. RESULTS: A novel ion imprinted approach combined with microfluidic technology was explored. Cu2+ was taken as ionic template and chitosan was used as carrier material. Chemical crosslinking was applied in the formation of imprinted sign. A selective biosorbent of ion-imprinted microspheres (IIMS) with uniform size, regular shape and high performance for Cu2+ had been prepared. The SEM, FTIR, EDS, XPS were employed to detect their distinct features. IIMS showed much higher adsorption capacity (q(m) = 81.97 mg g(-1)) than those non-imprinted chitosan microspheres (CSMS). The adsorption isotherm fitted the Langmuir equation while thermodynamic adsorption results were considered strong proof of an adsorption exothermal process. IIMS exhibited excellent selectivity for Cu2+ when competitive metal ions and Cu2+ co-existed together, which profited from the specific spaces of Cu2+ template left after crosslinking and desorption. Results confirmed that chemical adsorption was dominant and amino played an important role in adsorption process. CONCLUSION: IIMS showed high adsorption capacity and excellent selectivity for Cu2+. Combining microfluidic technology with an ion-imprinted method proved to be a promising process for preparing selective materials. (c) 2017 Society of Chemical Industry