Mutual facilitations of food waste treatment, microbial fuel cell bioelectricity generation and Chlorella vulgaris lipid production

Food waste contains large amount of organic matter that may be troublesome for handing, storage and transportation. A microbial fuel cell (MFC) was successfully constructed with different inoculum densities of Chlorella vulgaris for promoting food waste treatment. Maximum COD removal efficiency was registered with 44% and 25 g COD L−1 d−1 of substrate degradation rate when inoculated with the optimal initial density (150 mg L−1) of C. vulgaris, which were 2.9 times and 3.1 times higher than that of the abiotic cathode. With the optimum inoculum density of C. vulgaris, the highest open circuit voltage, working voltage and power density of MFC were 260 mV, 170 mV and 19151 mW m−3, respectively. Besides the high biodiesel quality, promoted by MFC stimulation the biomass productivity and highest total lipid content of C. vulgaris were 207 mg L−1 d−1 and 31%, which were roughly 2.7 times and 1.2 times higher than the control group.