Electrode and azo dye decolorization performance in microbial-fuel-cell-coupled constructed wetlands with different electrode size during long-term wastewater treatment

Abstract

Microbial-fuel-cell-coupled constructed wetlands (CW-MFCs) with various cathode layers were used for long-term azo dye wastewater treatment. Their performance was assessed using cathode diameters ranging from 20 to 27.5cm and the influence of plants at the cathode was also examined. Bioelectricity generation, ABRX3 decolorization, and chemical oxygen demand (COD) removal performances first increased and then decreased with increasing cathode diameter. The CW-MFCs with larger cathodes had an anoxic region at the cathode where ABRX3 was decolorized. This phenomenon has not been reported in previous research on MFCs using traditional air cathodes. Anode performance was influenced by the cathode. The CW-MFC with a cathode diameter of 25cm showed the best electrode performance, and the highest voltage and power density were 560mV and 0.88W/m, respectively. The highest ABRX3 decolorization and COD removal volumes were 271.53mg/L and 312.17mg/L, respectively.

Electrosorption of phenolic compounds from olive mill wastewater: Mass transport consideration under a transient regime through an alginate-activated carbon fixed-bed electrode

“…Tafel slopes were obtained from linear sweep voltammetry (LSV) with -2 to 2 V vs. Ag/AgCl as the voltage range and 0.01 V s −1 as the scan rate and were used to calculate the exchange current density (I 0 ) of the 3D porous electrode (Adnan et al, 2021b;Fang et al, 2017;Mousset et al, 2016b). Electrochemical impedance spectroscopy (EIS) using the frequency range from 50,000 to 0.1 Hz and an amplitude of 10 mV was performed to characterize the working electrode/electrolyte interface using the equivalent electrical circuit (EEC) method (Mousset et al, 2016b).…”

Malachite Green Removal and Bioelectricity Generation Using a Novel Design Multi-Electrode Microbial Fuel Cell

“…Their results indicated this system could be used for azo dye removal with 85% efficiency. Moreover, some works combined a MFC system with wetland to remove an azo dye, and they found that in optimal conditions, the MFC system could remove a toxic dye, and generate high voltage potential (Fang et al, 2017). No previous work explained a single use of MFC system for MG removal.…”

Recent progress in microbial fuel cells using substrates from diverse sources

“…Several studies have been performed to treat azo dye and simultaneously generate electricity [ 175 , 176 , 177 , 178 ]. One study used a single-chamber air-cathode MFC for electrical generation from the degradation of azo dyes [ 179 ].…”

“…The process enhanced the dye color removal efficiency, COD removal, and electricity generation and suggested the benefits of MFCs in biodegradation and bioelectricity generation. MFCs coupled with wetlands were also used for azo degradation [ 177 , 182 , 183 , 184 ]. In one study, at a cathode diameter of 25 cm, the highest decolourization volume of 397.64 mg L −1 was observed, whereas at a 27.5 cm diameter, a CD max of 0.539 A m −2 was recorded.…”