A novel coupled system combining up flow anaerobic sludge blankets（UASB） and microbial fuel cells（MFC） was designed for online monitoring the anaerobic digestion processes of UASB. The start of the UASB-MFC system and the formation of bio-particles were studied, and the correlation between suspension COD concentration and MFC voltage were evaluated. The situation of MFC voltage feedback under imbalance system conditions was studied. The results show that this coupled reactor can achieve quick start in 23 days to produce bio-particles. There exists certain correlation between voltage signal and substrate concentration under influent concentrations of 1000~3000 mg？L-1, in this stage the treatment efficiency of the UASB is relatively high. The MFC voltage increases slowly under lower influent concentrations, which demonstrates the UASB reactor is under low-load operation. Mean while, high influent concentrations led to MFC voltage decrease and system be acidified, which restrains microbial activity and decreases COD removal efficiency. The operation of MFC is stable during 180 days of operation. These results suggest that the MFC signal can reflect dynamic variation of UASB and can potentially be a valuable tool for monitoring and controlling the bio-processes.
Journal of Chemical Engineering of Chinese Universities