Influence Of Cu On The Performance Of Sediment Microbial Fuel Cell

Microbial fuel cell (MFC) is an emerging technology used to harvest electricity with thepollutant removal. Sediment MFC (SMFC) is a device by burying the anode in sediment andsuspending the cathode in an oxygen-rich water phase. It is a promising technology that issuitable for the in-situ remediation of lake and river sediment as well as the disposal of solidwaste. However, with the development of heavy industry, the heavy metal pollution insediment is increasingly severer and severer, which brings a serious challenge for the practicalapplication of SMFC. Therefore, it is significance to investigate the effect of heavy metals onthe performance of SMFC. The main research contents and results are as follows:(1) Is it feasible to take KCl as the electrolyte of SMFC? The voltage peak of KCl SMFCwas152.8±2.6mV. Compared with PBS, it was reduced by25%. Due to its low conductivityand the lack of buffering capacity, the system of KCl solution had a larger internal resistance,which declined the output voltage, COD removal rate and coulombic efficiency.(2) How does Cu influence on the performance of SMFC? The effect of Cu on the outputvoltage, EPS content and its composition were studied. The species distribution of Cu inSMFC showed that more than70%of Cu was combined with organics, carbonate and sulfide.Therefore, the presence of Cu did not significantly influence on output voltage. Anotherreason was that Cu can affect the anode and cathode simultaneously.(3) How does Cu influence on the performance of dual-chamber MFC? Cu can affect theanode and cathode simultaneously, and the effect was different. It showed that10mg/L Cuinto the anodic chamber inhibited the microbial activity, and increased the anodic activationresistance as well as the apparent internal resistance, consequently reduced the power outputand coulombic efficiency of the system. However,500mg/L Cu into the cathodic chambersignificantly reduced the cathodic activation resistance as well as the apparent internalresistance, improved the power output and the coulombic efficiency. When adding Cu into thecathodic chamber, it was mainly reduced and deposited on the cathodic chamber. It alsotransferred/diffused to the anodic chamber across the proton exchange membrane (2.8%)because of its concentration difference, thus affecting the microbial activity.(4) How does Cu influence on the performance of pre-biofilm SMFC? It showed that1mg/L and3mg/L Cu added into SMFC reactor promoted the microbial activity, and reducedthe anodic and cathodic resistance as well as the apparent internal resistance, consequentlyincreased the power output, COD removal rate and coulombic efficiency. However,7mg/Land12mg/L Cu increased the anodic resistance and reduced the cathodic resistance. Becausethe former is greater than the latter, the power output, COD removal rate and coulombicefficiency decreased.