Microbial Fuel Cell Treatment Research Articles

Reclamation and characterization of value-added products from pulp and paper mill effluent using microbial fuel cell

Pulp and paper industry is considered as the most polluted industry due to its toxic effect on environment. In the present investigation we report the novel method for the modification of highly complex organic substrates present in pulp and paper mill wastewater into value added products by using microbial fuel cell strategy. Microbial fuel cell (MFC) is an eco-friendly and energy-efficient technology to treat variety of wastewater with the simultaneous production of electricity. The sun-dried residue after the MFC treatment was characterized by FT-IR spectroscopy and SEM analysis. The microbial action breaks down, depolymerizes, and degrades the complex polymeric organic substrates present in pulp and paper mill effluent, resulting in the creation of small aromatic and aliphatic molecules. Upon treatment the surface morphology of residue changed significantly as it became extremely rough. The analysis of the by-products obtained via Microbial degradation was carried out using GC–MS. It has been observed that the pulp and paper mill wastewater which rich in lignin get converted into value-added products such as vanillin, acetic acid, valeric acid, glycerol and various alcohols. The number of peaks comprising the low-molecular weight compounds reached the maximum value upon 60 h of operation of GC–MS.

Hair hydrolysate functionalized cellulose nanocrystal based chitosan membrane to harness power from wastewater fed MFCs

Chitosan (CS) is an environmentally benign polymer increasingly utilized to prepare low-cost proton exchange membranes (PEMs) for Microbial Fuel Cell (MFC) applications. In this work, hair hydrolysate functionalized CNCs have been utilized with CS matrix followed by cross-linking with epichlorohydrin to enhance the properties of neat chitosan for its application as Nafion-alternative membrane to harvest electricity from domestic wastewater fed MFC device for the first time. Characterizations reveals the structural interaction between the hair hydrolysate functionalized CNC and chitosan matrix resulting in higher antibacterial property with a low percentage of water uptake (60%) and swelling (26%) and higher ion conductivity (1.04 mS/cm). Maximum power density of 142.57 mW/m2 and maximum open circuit voltage of 769.58 mV is derived from real wastewater which is higher compared to previous literature. The results demonstrate the possibility of application of the new low-cost, sustainable PEM with enhanced properties for MFC and wastewater treatment in future.

The fate of antibiotic resistance genes (ARGs) and mobile genetic elements (MGEs) from livestock wastewater (dominated by quinolone antibiotics) treated by microbial fuel cell (MFC)

The removal characteristics of antibiotic resistance genes and mobile genetic elements from livestock wastewater (dominated by quinolone antibiotics) treated with MFC were evaluated by High-throughput quantitative (HT-qPCR). The results showed that 144 ARGs and 8 MEGs were detected in the livestock wastewater. After MFC treatment, the number of AGRs decreased as a whole, and the relative abundance of macrolide-lincosamide-streptogramin group B (MLSB) and aminoglycosider decreased by 62.7% and 92.9%, respectively. MGEs decreased by 57.3% and multidrug genes decreased by 90%. After MFC treatment, the absolute abundance of tetracycline in raw sewage decreased by two orders of magnitude from 5.8 × 105 copies L−1 to 5.1.× 103 copies L−1. However, MFC was less efficient in the removal of vancomycin and beta-lactamase genes. It was also found that chloramphenicol resistance genes slightly increased. Illumina sequencing showed that Syntrophobacterales and Synergistales were predominant in MFCs. Desulfovibrio was resistant to high concentration of moxifloxacin hydrochloride. The removal efficiency of MFC for moxifloxacin hydrochloride at a concentration of 5 mg L−1 was 86.55%. The maximum power density and coulomb efficiency were 109.3 mV·cm−3 and 41.97%, respectively. With the increase of antibiotic concentration, the sewage treatment efficiency and electrical performance were inhibited. This study shows that untreated livestock wastewater had a great risk of gene horizontal transfer. Although MFC had limited treatment capacity for high-concentration quinolone wastewater, it is an effective method to reduce ARGs and the risk of horizontal gene transfer.

Cathode catalyst prepared from bacterial cellulose for ethanol fermentation stillage treatment in microbial fuel cell

• The prepared P-Cu-BC in MFC increased ethanol fermentation stillage treatment efficiency. • P-Cu-BC as catalyst precursors for MFC obtained a coulombic efficiency of 26%. • The biotoxicity removal rate of the fermentation stillage by MFC treatment can reach 84.7%. Bacterial cellulose doped with P and Cu was used as a catalyst for a microbial fuel cell (MFC) cathode, which was then used to treat ethanol fermentation stillage from food waste. Corresponding output power, coulombic efficiency (CE), and biological toxicity were detected. Through a series of characterization experiments, the addition of the cathode catalyst was found to improve catalytic activity and accelerate the consumption of the substrate. The resulting maximum output power was 572.16 mW·m −2 . CE and the removal rate of chemical oxygen demand (COD) in the fermentation stillage by P-Cu-BC reached 26% and 64.5%, respectively. The rate of biotoxicity removal by MFC treatment reached 84.7%. The aim of this study was apply a novel catalyst for MFC and optimize the treatment efficiency of fermentation stillage.

Anaerobic wastewater treatment and reuse enabled by thermophilic bioprocessing integrated with a bioelectrochemical/ultrafiltration module

The current study aimed to develop an anaerobic wastewater treatment and reuse module enabled by thermophilic bioprocessing, a microbial fuel cell (MFC) and ultrafiltration (UF) treatment. A previously unexplored consortium based on Thermoanaerobacterium thermosaccharolyticum and Arcobacter sp. was used to remove ~73% of chemical oxygen demand (COD) from wastewater under anaerobic conditions (CODi = 200 mg/L). The subsequent MFC and UF treatment removed the COD remnants to meet the secondary treatment standards and reuse criteria. The energy efficiency of polyethersulfone UF membranes was improved by modifying their surfaces with coatings based on self-polymerized dopamine, mixtures of dopamine and poly(2-dimethylamino) ethyl methacrylate methyl, and dopamine analog norepinephrine. The resulting hydrophilic, anti-fouling layers were found to reduce interactions between rejected species and the membrane surface. Finally, this study presents a comparative treatment performance and energy efficiency of the wastewater treatment and reuse modules arranged in six different configurations.

Improved Performance of Microbial Fuel Cell by In Situ Methanogenesis Suppression While Treating Fish Market Wastewater.

The fish market wastewater, which is rich in ammonium concentration, was investigated to explore its ability of in situ suppression of methanogenesis in the anodic chamber of microbial fuel cell (MFC) while treating it and to ensure non-reoccurrence of methanogenic consortia in the anodic chamber during its long-term operations. A lower specific methanogenic activity (0.097g chemical oxygen demand (COD)CH4/g volatile suspended solids (VSS). day) with a higher power density (3.81 ± 0.19W/m3) was exhibited by the MFC operated with raw fish market wastewater as compared to the MFC fed with synthetic wastewater (0.219g CODCH4/g VSS. day and 1.75 ± 0.09W/m3, respectively). The enhanced electrochemical activity of anodic biofilm of MFC fed with raw fish market wastewater than the MFC fed with synthetic wastewater further advocated the enhanced electrogenic activity and suppression of methanogenesis, because of the presence of higher ammonium content in the feed. This, in response, reduced the internal resistance (55Ω), enhanced the coulombic efficiency (21.9 ± 0.3%) and normalized the energy recovery (0.27 kWh/m3) from the MFC fed with fish market wastewater than the MFC fed with synthetic wastewater (92Ω, 15.7 ± 0.3% and 0.13kWh/m3, respectively). Thus, while treating the fish market wastewater in the anodic chamber of MFC, any costly and repetitive treatment procedures for anodic microorganisms are not required for suppression of methanogens to ensure higher activity of electrogenic bacteria for higher electricity harvesting.

Performance and toxicity assessment of an up-flow tubular microbial fuel cell during long-term operation with high-strength dairy wastewater

This study describes the development of an up-flow tubular air-cathode microbial fuel cell (MFC) bioreactor inoculated with a consortium of Shewanella oneidensis and Clostridium butyricum, fed with dairy wastewater (DW). Due to the high organic load of dairy wastewater, the MFC was operated using different strategies for the start-up (30 days) and the subsequent treatment phases (phase 1: 75 days; phase 2: 30 days). The removals of total chemical and biochemical oxygen demand (TCOD and TBOD) were 94 and 96%, under external resistance of 1.0 kΩ (phase 1), and 96 and 97%, under external resistance of 0.3 kΩ (phase 2). In addition, the MFC treatment provided high efficiency for the removal of organic nitrogen (47%), phosphorus (95%), nitrate (100%), and sulfate (75%). The MFC bioreactor delivered maximum power density of 3.5 W m−3 and current density of 1.1 A m−3 at the end of phase 1, and 2.4 W m−3 and 2.4 A m−3 in phase 2, but achieved modest Coulombic efficiency of 2.1% (phase 1) and 4.4% (phase 2), probably due to other metabolic pathways, besides the electrogenic one. Evaluation of the toxicity of the treated DW at two different trophic levels revealed no acute toxic effects towards Daphnia similis (immobilization less than 20%), but statistically significant chronic toxic effects towards Raphidocelis subcapitata (60% inhibition, using a concentrated sample). The findings indicated that the MFC constructed here had excellent potential for dairy wastewater treatment and energy recovery, and that toxicity assessment should be integrated with the MFC process.

Microalgal remediation of anaerobic pretreated pharmaceutical wastewater for sustainable biodiesel production and electricity generation

Raw wastewater from final processing unit of pharmaceutical industry contains high organic loading and obstinate compounds causing treatment of this wastewater a major challenge. In this study a novel approach for the treatment of pharmaceutical wastewater has been discussed. Anaerobic pretreatment of raw pharmaceutical wastewater was done using microbial fuel cell (MFC), followed by aerobic microalgal treatment with T. indica in photobioreactor in batch mode. Combined MFC and algal treatment process showed potential reduction in heavy metals concentration along with decrease of COD, TOC, nitrate and phosphate content. The observed COD, TOC, nitrate and phosphate in raw wastewater was 90.29, 97.05, 81.60 and 94.87 %, respectively. However, after treatment of raw wastewater in photobioreactor without pretreatment, 66.30 % COD, 67.17 % nitrate, 70.03 % phosphate and 78.14 % TOC reduction were observed. T. indica achieved 16.40 and 15.69 mg L−1d−1 of lipid productivity in PW1 and PW2 whereas it showed 0.085 and 0.089 g CO2 L−1d-1 of CO2 Fixation rate. This study demonstrates combination treatment processes of wastewater improve environmental sustainability and enables greener routes of biofuels production.

On Site Evaluation of a Tubular Microbial Fuel Cell Using an Anion Exchange Membrane for Sewage Water Treatment

This study evaluated the performance of a tubular microbial fuel cell (MFC) having a core of air-chamber wrapped with an anion exchange membrane in sewage wastewater treatment. Three MFCs were vertically assembled into one module and floated in sewage water channels before and after the treatment in primary sedimentation tank. The two MFC-modules showed almost similar electricity production in the range of 1.3–5.7 Wh·m-3-MFC, while the bottom MFCs (60–90 cm) showed a decrease in electricity than the top MFC (0–30 cm) and the middle MFC (30–60 cm). One of the MFC modules was then evaluated for the COD removal rate with two external resistances of 27 and 3, in a chemostat reactor (MFC:reactor = 1:5, v/v) under three hydraulic retention times (HRTs), 3 h, 6 h, and 12 h. The best COD removal rate of the MFC (COD-RTMFC), 54 ± 14% and BOD removal rate, 37 ± 17%, were observed with 3 of resistance and 12 h of HRT, resulting in 3.8 ± 2.0 A·m-3 of current recovery and 15 ± 7.5 % of Coulombic efficiency. Electricity generation efficiency (EGEMFC) was the best with 27 of resistance and 12 h of HRT and accounted for 0.18 ± 0.11 kWh·kg-COD-1 with 17 ± 6.4 % of COD-RTMFC and 0.65 ± 0.10 Wh·m-3 electricity production. Based on the calculation using the COD-RTMFC and EGEMFC, wastewater treatment can reduce electricity consumption by 55% via integration of the MFC treatment prior to the aeration.

Simultaneous bioelectricity generation from cost-effective MFC and water treatment using various wastewater samples

Worldwide, the requirement of electrical energy has increased with an increase in population. Thus, there is a need to develop an alternative source of sustainable energy, such as microbial fuel cell (MFC). MFC is a better option of energy generation and can provide a renewable resource which utilizes wastewater into power by the help of microorganisms. MFC is one of the advanced methods for treating wastewater and simultaneously producing current and voltage. Dual-chambered MFC was prepared using two plastic boxes (500 ml) by using wastewater as an anolyte. Different types of mediators are used in MFC including methylene blue, potassium ferricyanide, and EDTA to facilitate and higher the efficiency of electron transfer from the MFC to the electrode. Maximum OCV and current output of sample 1 (Budha Talab pond water) were 0.86 V and 75.1 mA and of sample 2 (Jaypee cement plant) were 1.42 V and 122 mA. The maximum current output of sample 3 (sugar industry, sewage waste, NIT canteen) was 1.3 V. Various physiochemical parameters such as dissolved oxygen (DO), biochemical oxygen demand (BOD), and chemical oxygen demand (COD) were analyzed which affect the power output. The obtained result concluded that wastewater should be feed at a certain time interval to avoid the loss of substrate for organisms in the anodic chamber which lead to the death of themicroorganism. Among all, sugar industry wastewater has a high potential for power generation as their physiochemical results are suitable for better power output.

Comparative Evaluation of Coated and Non-Coated Carbon Electrodes in a Microbial Fuel Cell for Treatment of Municipal Sludge

This study aims to provide insight into the cost-effective catalyst on power generation in a microbial fuel cell (MFC) for treatment of municipal sludge. Power production from MFCs with carbon, Fe2O3, and Pt electrodes were compared. The MFC with no coating on carbon generated the least power density (6.72 mW·m−2) while the MFC with Fe2O3-coating on carbon anodes and carbon cathodes generated a 78% higher power output (30.18 mW·m−2). The third MFC with Fe2O3-coated carbon anodes and Pt on carbon as the cathode catalyst generated the highest power density (73.16 mW·m−2) at room temperature. Although the power generated with a conventional Pt catalyst was more than two-fold higher than Fe2O3, this study suggests that Fe2O3 can be investigated further as an efficient, low-cost, and alternative catalyst of Pt, which can be optimized for improving performance of MFCs. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) results demonstrated reduced resistance of MFCs and better charge transfer between biofilm and electrodes containing coated anodes compared to non-coated anodes. Scanning electron microscopy (SEM) was used to analyze biofilm morphology and microbial community analysis was performed using 16S rRNA gene sequencing, which revealed the presence of known anaerobic fermenters and methanogens that may play a key role in energy generation in the MFCs.

Simultaneous energy generation and UV quencher removal from landfill leachate using a microbial fuel cell.

The presence of UV quenching compounds in landfill leachate can negatively affect UV disinfection in a wastewater treatment plant when leachate is co-treated. Herein, a microbial fuel cell (MFC) was investigated to remove UV quenchers from a landfill leachate with simultaneous bioelectricity generation. The key operating parameters including hydraulic retention time (HRT), anolyte recirculation rate, and external resistance were systematically studied to maximize energy recovery and UV absorbance reduction. It was found that nearly 50% UV absorbance was reduced under a condition of HRT 40days, continuous anolyte recirculation, and 10Ω external resistance. Further analysis showed a total reduction of organics by 75.3%, including the reduction of humic acids, fulvic acids, and hydrophilic fraction concentration as TOC. The MFC consumed 0.056kWhm-3 by its pump system for recirculation and oxygen supply. A reduced HRT of 20days with periodical anode recirculation (1 hour in every 24 hours) and 39Ω external resistance (equal to the internal resistance of the MFC) resulted in the highest net energy of 0.123kWhm-3. Granular activated carbon (GAC) was used as an effective post-treatment step and could achieve 89.1% UV absorbance reduction with 40gL-1. The combined MFC and GAC treatment could reduce 92.9% of the UV absorbance and remove 89.7% of the UV quenchers. The results of this study would encourage further exploration of using MFCs as an energy-efficient method for removing UV quenchers from landfill leachate.

Cometabolic degradation of chloramphenicol via a meta-cleavage pathway in a microbial fuel cell and its microbial community

The performance of a microbial fuel cell (MFC) in terms of degradation of chloramphenicol (CAP) was investigated. Approximately 84% of 50mg/L CAP was degraded within 12h in the MFC. A significant interaction of pH, temperature, and initial CAP concentration was found on removal of CAP, and a maximum degradation rate of 96.53% could theoretically be achieved at 31.48°C, a pH of 7.12, and an initial CAP concentration of 106.37mg/L. Moreover, CAP was further degraded through a ring-cleavage pathway. The antibacterial activity of CAP towards Escherichia coli ATCC 25922 and Shewanella oneidensis MR-1 was largely eliminated by MFC treatment. High-throughput sequencing analysis indicated that Azonexus, Comamonas, Nitrososphaera, Chryseobacterium, Azoarcus, Rhodococcus, and Dysgonomonas were the predominant genera in the MFC anode biofilm. In conclusion, the MFC shows potential for the treatment of antibiotic residue-containing wastewater due to its high rates of CAP removal and energy recovery.

Electricity generation from food wastes and characteristics of organic matters in microbial fuel cell

The microbial fuel cell (MFC) was evaluated as an alternative way to recover electricity from canteen based food waste. Characteristics of the organics in food waste before and after the MFC treatment were analyzed to investigate how the organic matters were biodegraded and transformed during the MFC treatment. A maximum power density of 5.6W/m3 and an average output voltage of 0.51V were obtained. During the MFC operation, the hydrophilic and acidic fractions were more readily degraded, compared to the neutral fractions. Additionally, aromatic compounds in the hydrophilic fraction were more preferentially removed than non-aromatic compounds. The MFC could easily remove the tryptophan protein-like substances in all fractions and aromatic proteins in hydrophilic and hydrophobic neutral fractions. Additionally, the hydrophobic amide-1 proteins and aliphatic components were readily hydrolyzed and biodegraded in the MFC. These findings may facilitate the pretreatment and posttreatment choices for MFC system fed with food waste.

Rapid degradation of sulphamethoxazole and the further transformation of 3-amino-5-methylisoxazole in a microbial fuel cell

Sulphamethoxazole (SMX) is extensively used in humans and livestock, but its appearance in natural water raises environmental concerns. This study demonstrated that SMX and its degradation product, 3-amino-5-methylisoxazole (3A5MI), could be effectively degraded in microbial fuel cell (MFC) reactors. Approximately 85% of 20 ppm SMX was degraded within 12 h, and this was a more rapid biodegradation rate than has been previously shown in the literature. In addition, 3A5MI, a toxic chemical that forms in the SMX degradation process, can be further mineralized. The degradation products of SMX were detected by mass spectrometry, and three speculated by-products were confirmed with chemical standards. It was observed that nitrogen atoms of SMX were progressively eliminated during the degradation process, which may relate with the degradation of SMX and 3A5MI. An antibacterial activity test showed that the biotoxicity of SMX towards Shewanella oneidensis MR-1 and Escherichia coli DH5α was greatly reduced after MFC treatment. Moreover, the ATP level of the MFC microbe was nearly threefold higher than that in open-circuit controls, which may be related to the rapid degradation of SMX in MFCs. This study can facilitate further investigations about the biodegradation of SMX.

Complete degradation of the azo dye Acid Orange-7 and bioelectricity generation in an integrated microbial fuel cell, aerobic two-stage bioreactor system in continuous flow mode at ambient temperature

In this study, the commercially used model azo dye Acid Orange-7 (AO-7) was fully degraded into less toxic intermediates using an integrated microbial fuel cell (MFC) and aerobic bioreactor system. The integrated bioreactor system was operated at ambient temperature and continuous-flow mode. AO-7 loading rate was varied during experiments from 70gm(-3)day(-1) to 210gm(-3)day(-1). Colour and soluble COD removal rates reached>90% under all AO-7 loading rates. The MFC treatment stage prompted AO-7 to undergo reductive degradation into its constituent aromatic amines. HPLC-MS analysis of metabolite extracts from the aerobic stage of the bioreactor system indicated further oxidative degradation of the resulting aromatic amines into simpler compounds. Bioluminescence based Vibrio fischeri ecotoxicity testing demonstrated that aerobic stage effluent exhibited toxicity reductions of approximately fivefold and ten-fold respectively compared to the dye wastewater influent and MFC-stage effluent.

Energy and Performance Comparison of Microbial Fuel Cell and Conventional Aeration Treating of Wastewater

Microbial fuel cell (MFC) technology provides a low cost alternative to conventional aerated wastewater treatment, however, there has been little comparison between MFC and aeration treatment using real wastewater as the substrate. This study attempts to directly compare the wastewater treatment efficiency and energy consumption and generation among three reactor systems-a traditional aeration process, a simple submerged MFC configuration, and a control reactor acting similar as natural lagoons. Results showed that all three systems were able to remove >90% of COD, but the aeration used shorter time (8 days) than the MFC (10 days) and control reactor (25 days). Compared to aeration, the MFC showed lower removal efficiency in high COD concentration, but much higher efficiency when the COD is low. Only the aeration system showed complete nitrification during the operation, reflected by completed ammonia removal and nitrate accumulation. Suspended solid measurements showed that MFC reduced sludge production by 52-82% as compared to aeration, and it also saved 100% of aeration energy. Furthermore, though not designed for high power generation, the MFC reactor showed a 0.3 Wh/g COD/L or 24 Wh/m3 (wastewater treated) net energy gain in electricity generation. These results demonstrate that MFC technology could be integrated into wastewater infrastructure to meet effluent quality and save operational cost.

Electricity generation from dissolved organic matter in polluted lake water using a microbial fuel cell (MFC)

A microbial fuel cell (MFC) was explored as a pretreatment method to remove dissolved organic matter (DOM) from polluted lake water and simultaneously generate electricity. After the MFC treatment, the total organic carbon concentration in the raw lake water was reduced by 50%, the physicochemical nature of DOMs was substantially altered. Protein-like substances in lake water were utilized as a major substrate for the MFC, while humic-like substances were refractory to the biodegradation. A further investigation into the bovine serum albumin utilization in an MFC confirms that the electricity generation was closely associated with the removal of protein-like substrates. Toxicity assessment by Salmonella typhimurium Sal94 indicates that the genotoxic agents in the polluted lake water were almost completely removed after the MFC treatment. This approach of coupling microbially-catalyzed electricity generation with DOM removal may offer a potential avenue for energy-efficient bioremediation of lake water.

Characterization of Strain Pseudomonas sp. Q1 in Microbial Fuel Cell for Treatment of Quinoline-Contaminated Water

To find new strain in the microbial fuel cell (MFC) for quinoline removal from wastewater and soil, a facultative anaerobic bacterium strain was isolated from the anode of MFC, utilizing quinoline as the carbon source and electron donor. Based on the 16S rRNA sequence analysis, the bacterium strain was Gram-negative and identified as Pseudomonas sp. Q1 according to its morphology and physiochemical properties. The strain was inoculated into a double-chambered MFC using various quinoline concentrations (0, 50, 75, 86, 100, 150, 200 and 300 mg L−1) combining with 300 mg L−1 glucose as the fuel. Results showed that electricity was generated from the MFC, in which quinoline was degraded simultaneously. The values of Coulombic efficiency (CE) increased with the increase of quinoline concentrations from 0 to 100 mg L−1 then decreased with the increase of quinoline concentration from 100 to 300 mg L−1, and the maximum CE 36.7% was obtained at the quinoline concentration of 100 mg L−1. The cyclic voltammetry analysis suggested that the mechanism of electron transfer was through excreting mediators produced by the strain Q1. The MFC should be a potential method for the treatment of quinoline-contaminated water and soil.

Degradation of algal organic matter using microbial fuel cells and its association with trihalomethane precursor removal

In order to provide an alternative for removal of algal organic matter (AOM) produced during algal blooms in aquatic environment, microbial fuel cell (MFC) was used to study AOM degradation and its association with THM precursor removal. The chemical oxygen demand (COD) removals in MFCs were 81±6% and 73±3% for AOM from Microcystis aeruginosa (AOMM) and Chlorella vulgaris (AOMC), respectively. THM precursor was also effectively degraded (AOMM 85±2%, AOMC 72±4%). The major AOM components (proteins, lipids, and carbohydrates) were obviously removed in MFCs. The contribution of each component to the THM formation potential (THMFP) was obtained based on calculation. The THMFP produced from soluble microbial products was very low. If the energy input during operation process was not considered, MFCs treatment could recover electrical energy of 0.29±0.02kWh/kg COD (AOMM) and 0.35±0.06kWh/kg COD (AOMC).