Low-Cost Single Chamber MFC Integrated With Novel Lignin-Based Carbon Fiber Felt Bioanode for Treatment of Recalcitrant Azo Dye

Abstract

A flow through anaerobic microbial fuel cell (MFC) was designed and optimized for efficient treatment of recalcitrant textile wastewater. The membrane-less MFC was first time fabricated with a unique combination of electrodes, a novel bioanode of synthesized lignin-based electrospun carbon fiber supporting a biofilm of Geobacter sulfurreducens for acetate oxidation and an air-breathing cathode, consisting of a pyrolyzed macrocycle catalyst mixture on carbon bonded by polytetrafluoroethylene (PTFE). The effects of different organic loadings of acetate along with Acid Orange (AO5), operation time and ionic strength of auxiliary salts (conductivity enhancers) were investigated and responses in terms of polarization and degradation were studied. In addition, the decomposition of the organic species and the degradation of AO5 along with its metabolites and degraded products (2-aminobenzenesulfonic acid) were determined by chemical oxygen demand (COD) analysis, UV-Vis spectrophotometry and high-performance liquid chromatography (UV-HPLC) techniques. SEM and TEM images were also used to find out the biocompatibility of the microbes on lignin-based electrospun carbon felt anode and the morphology of the cathode. Reduction and breakage of the azo bond of AO5 occurs presumably as a side reaction, resulting in the formation of 2-aminobenzenesulfonic acid and unidentified aromatic amines. Maximum current density of anode 0.59 Am−2 and power density of 0.12 Wm−2 were obtained under optimized conditions. As a result, decolouration of AO5 and chemical oxygen demand (COD) removal efficiency was 81 and 58%, respectively. These results revealed that the low-cost MFC assembly can offer significant potential for anaerobic decolouration of recalcitrant textile wastewater.

Enhancement of Power Generation and Organic Removal in Double Anode Chamber Designed Dual-Chamber Microbial Fuel Cell (DAC-DCMFC)

“…Electrodes consisted of GNPs (CAS# 9002-84-0) coated 30 mesh SSM as the anode of both anode chambers, and the big difference was cathode material that consisted of GNPs: PU 1:1 volume solution ratio-coated cathode at the code 1A, and GNPs-PTFE (CAS# 9002-84-0) 60% coated cathode at the code 2A. In addition, synthesized PU was water-based polyurethane [53] with a similar function to polytetrafluoroethylene (PTFE) [44,54,55] as a waterproofing material and increasing the oxygen reduction reaction (ORR) on the surface of the cathode material. The wiring system, called closed-circuit voltage (CCV) [56,57], connected the anode-equipped 100 Ω of resistor onto the data logger and cathode in a line.…”

“…Fundamentally, the configurations of MFC consist of a single chamber microbial fuel cell (SCMFC) and double chamber microbial fuel cell (DCMFC) [38]. The high performance of DCMFC is shown by the engineered electrode, such as multiple electrodes [39,40], nanomaterial-assisted electrode [41,42], low-cost material substituted electrode [43,44], separator [45,46], and multiple anode chamber called the integrated system with the wastewater treatment plant types (anaerobic digester, constructed wetland, up-flow anaerobic baffled reactor (UASB), etc.) [7,11,[47][48][49].…”

Untreated vs. Treated Carbon Felt Anodes: Impacts on Power Generation in Microbial Fuel Cells

“…Another study by Miran et al emphasized the role of iron oxide-modified carbon electrodes in tandem with sulfate-reducing bacteria for efficient bio-electricity generation [13]. Fatima and colleagues integrated a novel lignin-based carbon fiber felt bioanode in an MFC, demonstrating its potential for treating recalcitrant textile wastewater [14]. Additionally, Kim et al employed microwave and sulfuric acid treatments on graphite granules, resulting in a significant boost in bioelectricity generation in MFCs [15].…”