Self-sustained bioelectrical reduction system assisted iron–manganese doped metal-organic framework membrane for the treatment of electroplating wastewater

Heavy metals seriously endanger human health. However, simultaneous and efficient removal of heavy metals from wastewater has always been a technical challenge. For this purpose, we developed a self-sustained bioelectrical reduction system (SBRS) for the efficient purification of heavy metal wastewater. A novel iron-manganese doped metal-organic framework membrane (FM-MOFM) based on conductive substrate is used as the catalytic cathode electrode. The performances of the SBRS assisted FM-MOFM for heavy metals reduction and self-energy generation for the treatment of simulated electroplating wastewater were investigated. The FM-MOFMs were characterized before and after operation by SEM, XRD , XPS and other methods. Copper, zinc, chromium, nickel heavy metal ions are almost completely removed by the SBRS (removal efficiency: Copper ion 99.9%, Zinc ion 99.9%, Chromium ion 99.7% and Nickel ion 99.8%). Moreover, the organic substrates in the wastewater were removed simultaneously and efficiently (removal efficiency: COD 95.3%, NH 4 + -N 99.9%, TP 95.9%), with the maximum power density of 1.6 W m −3 . The possible electroreduction and electroflocculation mechanism of heavy metal ions can be understood by the characterization of the membrane electrode surface and precipitate. The study confirms that the SBRS is a potential and efficient candidate for the simultaneous removal of heavy metals from electroplating wastewater.