Removal, recycle and reutilization of multiple heavy metal ions from electroplating wastewater using super-stable mineralizer Ca-based layered double hydroxides

From an environmental and resource management perspective, it is preferable to recover and reuse heavy metal ions found in electroplating wastewater. The discharge of electroplating wastewater has caused serious environmental pollution and resource waste. Ca-based layered double hydroxides (LDHs) stabilizers are designed, which show a rapid, effective, and adequate capacity exceeding 400 mg/g against solutions of Cu2+, Zn2+, Co2+, and Ni2+ ions through an isomorphous substitution mechanism. The needs of plant development were met by the use of CaAl-LDH in soil remediation. While Cu resources can be recovered from the CuAl-LDH products by electrolysis, the final mineralization products from Ni2+ and Zn2+ ions showed exceptional performance in visible-light-induced photocatalytic reduction of CO2 with excellent selectivity (98.7% toward CO and CH4) and the removal of arsenite ions (99.97%). The results of this investigation revealed a feasible new approach to the removal, recycling, and reutilization of heavy metal ions.