In-situ ion exchange electrocatalysis biological coupling (i-IEEBC) for simultaneously enhanced degradation of organic pollutants and heavy metals in electroplating wastewater

The goal of this research was to develop a new process for simultaneously removing organics and heavy metals of electroplating wastewater by in-situ ion exchange electrocatalysis biological coupling (i-IEEBC). The study evaluated the removal efficiency of coexisting refractory organics and heavy metal ions, and investigated the effects of current density (CD) on the removal performance of the i-IEEBC method. The results indicated the i-IEEBC reactor exhibited higher average removal rates of COD, TOC, Cr and Cu ions, i.e. 87.23%, 80.42%, 91.25%, and 95.97% in that order, which represented an increase by 32.59%, 40.10%, 31.86%, and 33.82%, respectively, compared with BAF. The optimum CD for simultaneously removing organics and heavy metals of electroplating wastewater in i-IEEBC was 0.40 mA/(cm)(2). The change of biodegradability and the presence of short chain organic compounds also indirectly confirmed the excellent removal organic pollutants performance of i-IEEBC at the optimum CD. In addition, the composition and construction of CER before and after the application, under the optimum CD, SEM, EDS and FT-IR spectroscopy also showed that the cation exchange properties of CER improved the catalytic lifetime of the particle electrodes. This research provides a highly efficient new alternative to electroplating wastewater treatment technology.