Using multiple carbon brush cathode in a novel tubular photosynthetic microbial fuel cell for enhancing bioenergy generation and advanced wastewater treatment

Abstract

A novel tubular-type photosynthetic microbial fuel cell (PMFC) with algal growth and multiple electrodes in the cathode chamber was operated at various hydraulic retention times (HRTs). When the HRT in the cathode was fixed to 24 h, cell voltage gradually increased as the HRT in the anode was decreased from 24 h to 6 h, and at 6 h, 315 mV of electricity was generated and the dissolved oxygen concentration was 10.31 ± 2.60 mg/L. However, HRT changes in the cathode did not affect cell voltage generation much, although a sharp decrease in cell voltage was observed at 2-h HRT. With wastewater passing through the chambers in series (19.3-h total HRT), the PMFC was able to successfully generate cell voltage and remove nutrients. The maximum COD and phosphorus removal percentages were obtained for an initial COD of 300 mg/L, while the maximum nitrogen removal was obtained for an initial COD of 400 mg/L.