Influence of microbial fuel cell integration on organic matter and nutrient removal in a constructed wetland for wastewater treatment

The combination of constructed wetlands (CWs) and microbial fuel cells (MFCs) has emerged in recent years with the purpose of enhancing wastewater treatment efficiency of CWs while simultaneously generating electricity. Taking the above into account, the aim of this study is to evaluate the influence of MFC integration on organic matter and nutrient removal in a constructed wetland. The results showed that NH4+-N concentration reduced from 66.5 ±9.4 at day 0 (influent) to 4.5±0.4 mg/L and 7.03±3.93mg/L for the integrated system and control system, respectively. In terms of the NH4+-N removal efficiency, an enhancement of the nitrification rate (Ni) was observed when MFC was integrated in VSSF (120.6±1.5 mg/m2 d for control system and 166.8±2.3 mg/m2 d for integrated system). The average COD removal efficiencies were 89.36±2.67% and 94.2±5.9% in the CW and CW-MFC, respectively, obtaining a voltage close to 250 mV. The maximum power density generated was 4.75 mW/m2. In conclusion, the removal efficiencies of COD and NH4+-N in VSSF were 89.4 and 88.4%, respectively, while in CW-MFC were 94.3 and 93.2 %. Therefore, the integrating of a MFC into CW does not have adverse effects on the capacity of the CW to efficiently domestic wastewater treatment.