Liu Zhe, Xiang Ping, Duan Zhuang, Fu Zhaohui, Zhang Linfang, Zhang Zhi
College of Environment and Ecology, Chongqing University Chongqing 400045 China
Key Laboratory of Three Gorges Reservoir Region's Eco-Environment, Ministry of Education, Chongqing University Chongqing 400045 China.
RSC Adv. 2019 Aug 13;9(43):25189-25198. doi: 10.1039/c9ra04184b. eCollection 2019 Aug 8.
A three-chamber microbial desalination cell (MDC) was constructed for high-salinity mustard tuber wastewater (MTWW) treatment. The effect of anode COD on electricity generation, salinity, COD removal and the anodic biofilm microbial community in MDC for the MTWW treatment was investigated. The results showed that electricity generation was better when the anode COD was 900 mg L when it was 400 or 1400 mg L. The ionic strength and conductivity of the anolyte were higher than those at 400 mg L; thus, the ohmic internal resistance was lower. In addition, the mass transfer internal resistance was lower than that at 1400 mg L, which made the system internal resistance the lowest; consequently, the voltage and power density were the highest. The output voltage, power density and coulombic efficiency of the 1000 Ω external resistors were 555 mV, 3.03 W m and 26.5% ± 0.4%, respectively. Desalination was the highest when the anode COD was 400 mg L. The lowest ionic strength and osmotic pressure of the anolyte resulted in the strongest osmosis, thereby producing the highest desalination rate; the desalination rate was 5.33 mg h. When MDC was coupled with the dual-chamber microbial fuel cell (MFC), the desalinated MTWW could be used as the anode substrate of the MFC; its high COD could be removed continuously, and the COD removal values were 86.2% ± 2.5%, 83.0% ± 2.0% and 84.3% ± 2.4%. High-throughput sequencing analysis indicated that hydrolytic and fermentative bacteria were the core anode bacteria of MDC. The abundances of electrochemically active bacteria in the anode biofilms of the three groups were 11.78% (400 mg L COD), 14.06% (900 mg L COD) and 13.68% (1400 mg L COD). Therefore, the differences in anode CODs impacted the abundance of electrochemically active bacteria, which led to differences in electricity generation performances.
构建了一个三室微生物脱盐电池（MDC）用于处理高盐度榨菜废水（MTWW）。研究了阳极化学需氧量（COD）对MDC处理MTWW时发电、盐度、COD去除及阳极生物膜微生物群落的影响。结果表明，阳极COD为900 mg/L时的发电效果优于400 mg/L或1400 mg/L时。阳极电解液的离子强度和电导率高于400 mg/L时的；因此，欧姆内阻较低。此外，传质内阻低于1400 mg/L时的，这使得系统内阻最低；相应地，电压和功率密度最高。1000 Ω外接电阻时的输出电压、功率密度和库仑效率分别为555 mV、3.03 W/m和26.5%±0.4%。阳极COD为400 mg/L时脱盐效果最佳。阳极电解液最低的离子强度和渗透压导致最强的渗透作用，从而产生最高的脱盐率；脱盐率为5.33 mg/h。当MDC与双室微生物燃料电池（MFC）耦合时，脱盐后的MTWW可作为MFC的阳极底物；其高COD可被持续去除，COD去除率分别为86.2%±2.5%、83.0%±2.0%和84.3%±2.4%。高通量测序分析表明，水解和发酵细菌是MDC的核心阳极细菌。三组阳极生物膜中电化学活性细菌的丰度分别为11.78%（400 mg/L COD）、14.06%（900 mg/L COD）和13.68%（1400 mg/L COD）。因此，阳极COD的差异影响了电化学活性细菌的丰度，进而导致发电性能的差异。
