Synthesis of recyclable 3D LC/h-ZIF-8 by Zn(II) containing wastewater for photocatalytic degradation of mixed-dye under UV-Vis irradiation

The treatment process of metal plating wastewater in industry usually exists excessive consumption of chemicals, coproduction of sludge and complex reuse of metal. At present, some available technologies have been designed for effective removal of specific metal ions rather than entire metals ions in effluents. Herein, a novel strategy of treating waste with waste is proposed that using metal plating wastewater containing Zn(II) to prepare 3D Luffa cylindrical (LC) / heterogeneous ZIFs (h-ZIF-8) composite (LC/h-ZIF-8) for photocatalytic degradation of organic pollutants (Nitrofurazone (NFZ), Methylene blue (MB), Rhodamine B (RhB) and Congo red (CR)) and mixed-dye wastewater. The strategy realized the efficient treatment of electroplating wastewater, expediently reuse of metal ions and removal of organic contaminants. Moreover, investigations of cycling performance indicated the photocatalytic stability and easy separation from water. Furthermore, the spectroscopy and electrochemical are employed to elaborate possible degradation mechanisms, expounding the LC/h-ZIF-8 possess lower recombination rates of carriers and transfer resistance of electron compared with ZIF-8. Therefore, the work proposes a new strategy for the efficient treatment of metal wastewater and achieves the combination of resource recovery and wastewater treatment with the advantages of simple operation and mild conditions.