Preparation of anion exchange resin by recycling of waste printed circuit boards

Abstract

The traditional treatment of the non-metal components of waste printed circuit boards (WPCBs), mainly thermosetting epoxy resins (TEPRs), is very difficult because they are inflexible and insoluble, and thus a new method to convert them into anion exchange resin by chloromethylation and quaternization was studied. The ion exchange capacity (IEC) of the product is 2.4345 mmol g⁻¹ and the thermal stability is up to 200 °C. The application of the produced anion exchange resin to adsorption of Cr(VI) was studied in detail. The adsorption of Cr(VI) was confirmed by Raman spectroscopy and the maximum adsorption capacity was 47.85 mg g⁻¹. As for the isotherm adsorption model, the Langmuir model is more appropriate than Freundlich. The adsorption kinetics was determined and activation energy (E_a) was found to be 3.51 kJ mol⁻¹.