Simultaneous investigation of the increase in organic load of sediment using spirulina algae powder and increase in catholyte conductivity on sediment microbial fuel cell performance

Sediment microbial fuel cells (SMFCs) are Bioelectrochemical systems that have the ability to produce bioelectricity. However, the amount of low organic matter sediment limits their output power. Furthermore, another factor, which causes low Power generation capacity in Sediment microbial fuel cells, is the low conductivity of the catholyte. In the current paper, we employed spirulina algae powder to increase the organic load of the sediment. We also investigated the effect of catholyte conductivity on SMFC performance by using three different periods, including river water with a conductivity of 2mS, tap water with a conductivity of 243mS, and synthetic water with a conductivity of 2mS. The results of the power curves showed that the highest power density was produced by SMFC-1 (117.78 mW/m2), which improved by 77% compared to SMFC-01. In addition, according to the polarization curves of SMFC-1 and SMFC-01, the maximum current density also increased with increasing conductivity, so the highest current density was produced by SMFC-1 in the third phase. Also, CV and EIS analyses showed an increase in the current density rate and a fall in internal resistance. These findings showed that the use of spirulina algae powder as an additional substrate and increasing the conductivity of the catholyte can be considered as an effective approach to increase the power of SMFCs.