A microbial fuel cell-coupled constructed wetland promotes degradation of azo dye decolorization products

Abstract

a b s t r a c tMicrobial fuel cell coupled constructed wetland (CW-MFC) was constructed for azo dye decolorization and further degradation. Methyl Orange (MO) was chosen as the model azo dye due to the simple decolorization products. The decolorization products were analyzed qualitatively via GC-MS and the N,NDimethyl-p-phenylenediamine (DMPD) was chosen as one of the MO decolorization products to study the further degradation performance of decolorization products in the CW-MFC. 1,4-Benzenediamine, N-methyl-and p-Phenylenediamine (PPD) was another intermediate product of MO decolorization. Electrical characteristics of CW-MFC were studied to evaluate the interplay between the azo dye degradation and the electricity generation. The MO decolorization rate of open and closed-circuit CW-MFC were 75.59% and 87.60%, respectively, while the DMPD degradation rate in the anode layer of open and closedcircuit CW-MFC were 84.96% and 96.33%, respectively. In the anode layer, suitable anode materials can promote the further degradation of azo dye degradation products, while in the cathode layer, close current promoted the further degradation of the decolorization products.

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

“…The 20-cm and 20-cm-p CW-MFCs had negative ABRX3 decolorization volumes in the cathode layer, similar to observations in our previous study (Fang et al, 2016). This may have occurred because of evaporation in the cathode layer.…”

“…Therefore a part of treatment that happened in CW-MFCs was caused because bioelectrochemical. In our previous researches, we have setted control experiment that without circuit, the experimental results showed the circuit can improve the degradation of azo dyes (Fang et al, 2013;Fang et al, 2016). At low ABRX3 concentrations, the system did not require many electrons for ABRX3 decolorization or electricity generation.…”

“…4B). This was because glucose was more easily degraded than ABRX3, and the majority of glucose was degraded in the bottom layer (Fang et al, 2016). The 25-cm CW-MFC had the highest COD treatment volumes, 264.83 mg/L, 312.17 mg/L, and 311.69 mg/L during the three phases, respectively.…”

Decolourization and mineralization of Acid Red 27 metabolites by using multiple zoned aerobic and anaerobic constructed wetland reactor

“…Most researchers used glucose and sucrose as carbon source and model pollutants. However, there are limited studies on sodium benzoate [13,19,20]. Therefore, the authors chose sodium benzoate as model pollutant in this study.…”

Electrochemical enrichment of haloalkaliphilic nitrate-reducing microbial biofilm at the cathode of bioelectrochemical systems

“…For instance, Shewanella oneidensis MR-1 has been proposed to follow the reverse Mtr pathway of electron transfer for reductive metabolism ( Ross et al., 2011 ) and electron uptake from the cathode electrode ( Rowe et al., 2018 ). Several studies have reported on the electrotrophic mixed-culture microbial biofilms, grown with electron acceptors such as oxygen ( Rabaey et al., 2008 ), H + ions ( Aulenta et al., 2008 ), CO 2 ( Aryal et al., 2017 ), heavy metals, polyaromatic hydrocarbons, dyes, and so on ( Gregory and Lovley, 2005 ; Tandukar et al., 2009 ; Sharma et al., 2020 ; Fang et al., 2016 ). Notably, EAMs have been studied mostly from nonextreme environments, and only a few studies have reported the diversity of these microbes inhabiting extreme habitats ( Koch and Harnisch, 2016 ; Rowe et al., 2017 ; Logan et al., 2019 ; Yadav and Patil, 2020 ).…”