Design of an alternative approach for synergistic removal of multiple contaminants: water splitting coagulation

Abstract The development of novel technologies for wastewater treatment provides a reliable pathway to solve the growing environmental issues. Control on process cost, increment of pollutant removal efficiency, and multi-system applicability are key points which should be carefully considered. Here in this work, a novel method of ‘water splitting coagulation (WSC)’, which involves the synchronous treatment of two kinds of wastewater that contain metal and organic contaminants was proposed. As an electrical based technique, WSC utilizes ‘water splitting’ in a bipolar membrane (BM) instead of ‘water electrolysis’ on electrodes to constructively produce a flocculating constituent ( Ni ( O H ) x ( 2 - x ) + ) by controlling the ‘hydroxide delivery’ and ‘cation delivery’ inside a BM and across a cation exchange membrane. The metal hydroxide is capable of absorbing textile dyes in ( D y e ) y N i ( O H ) x ( 2 - x ) + form, which can be post-treated to produce useful resources. The alternative process has several advantages: 1) prevents the replacement of sacrificial anodes, 2) simultaneous removal of heavy metal and textile dyes, and 3) the recycling of valuable accompanying byproducts, and has great potential in the complex industrial wastewater treatment.