Xiong Xiao-Min, Wu Xia-Yuan, Jia Hong-Hua, Yong Xiao-Yu, Zhou Jun, Wei Ping
Bioenergy Research Institute, School of Biotechnology and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 211800, China.
Huan Jing Ke Xue. 2017 Oct 8;38(10):4262-4270. doi: 10.13227/j.hjkx.201703129.
The effect of copper (Ⅱ) wastewater addition on the treatment of chromium (Ⅵ) wastewater in dual-chamber microbial fuel cells (MFCs) was investigated for different Cr(Ⅵ)/Cu(Ⅱ) concentration ratios (2:1, 1:1, 1:2, 1:4) and external resistances (10, 500, 1000, 2000 Ω). The results demonstrated that the addition of Cu(Ⅱ) and Cr(Ⅵ) into the cathode chamber of MFCs could enhance the Cr(Ⅵ) removal efficiency. The Cr(Ⅵ) removal efficiency increased with the increase in the Cr(Ⅵ)/Cu(Ⅱ) concentration ratio. The Cu(Ⅱ) on the Cr(Ⅵ) removal efficiencies increased with the decrease of external resistance. The highest Cr(Ⅵ) removal efficiency achieved was 91.00% in MFC at the Cr(Ⅵ)/Cu(Ⅱ) concentration ratio of 1:4 and external resistance of 10 Ω, which was 132.57% higher than the MFC with Cr(Ⅵ) only (39.13%). The scanning electron microscopy with coupled energy dispersive spectroscopy (SEM-EDS) and X-ray photoelectron spectroscopy (XPS) analyses of the cathode electrode at the end of the experiments indicated that Cr(Ⅵ) reduced to non-conductive Cr(Ⅲ) deposits (CrO) on the cathode electrode, resulting in cathode deactivation which blocked the electron transfer. However, the addition of Cu(Ⅱ) could improve the electrical conductivity of the cathode due to its conductive reduzates (copper and CuO) on the cathode which could reduce the cathode deactivation and subsequently enhance the Cr(Ⅵ) removal efficiency.
研究了在双室微生物燃料电池（MFC）中添加铜（Ⅱ）废水对铬（Ⅵ）废水处理的影响，考察了不同的Cr（Ⅵ）/Cu（Ⅱ）浓度比（2:1、1:1、1:2、1:4）和外电阻（10、500、1000、2000Ω）。结果表明，向MFC的阴极室中添加Cu（Ⅱ）和Cr（Ⅵ）可以提高Cr（Ⅵ）的去除效率。Cr（Ⅵ）的去除效率随着Cr（Ⅵ）/Cu（Ⅱ）浓度比的增加而提高。Cu（Ⅱ）对Cr（Ⅵ）去除效率的影响随着外电阻的降低而增加。在Cr（Ⅵ）/Cu（Ⅱ）浓度比为1:4、外电阻为10Ω的MFC中，Cr（Ⅵ）的最高去除效率达到91.00%，比仅含Cr（Ⅵ）的MFC（39.13%）高132.57%。实验结束时对阴极电极进行的扫描电子显微镜与能谱联用（SEM-EDS）和X射线光电子能谱（XPS）分析表明，Cr（Ⅵ）在阴极电极上还原为非导电的Cr（Ⅲ）沉积物（CrO），导致阴极失活，阻碍了电子转移。然而，添加Cu（Ⅱ）可以提高阴极的电导率，因为其在阴极上的导电还原产物（铜和CuO）可以减少阴极失活，从而提高Cr（Ⅵ）的去除效率。
