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Increasing industrialization and urbanization have contributed to a significant rise in wastewater discharge and exerted extensive pressure on the existing natural energy resources. Microbial fuel cell (MFC) is a sustainable technology that utilizes wastewater for electricity generation. MFC comprises a bioelectrochemical system employing electroactive biofilms of several aerobic and anaerobic bacteria, such as Geobacter sulfurreducens, Shewanella oneidensis, Pseudomonas aeruginosa, and Ochrobacterum pseudiintermedium. Since the electroactive biofilms constitute a vital part of the MFC, it is crucial to understand the biofilm-mediated pollutant metabolism and electron transfer mechanisms. Engineering electroactive biofilm communities for improved biofilm formation and extracellular polymeric substances (EPS) secretion can positively impact the bioelectrochemical system and improve fuel cell performance. This review article summarizes the role of electroactive bacterial communities in MFC for wastewater treatment and bioelectricity generation. A significant focus has been laid on understanding the composition, structure, and function of electroactive biofilms in MFC. Various electron transport mechanisms, including direct electron transfer (DET), indirect electron transfer (IET), and long-distance electron transfer (LDET), have been discussed. A detailed summary of the optimization of process parameters and genetic engineering strategies for improving the performance of MFC has been provided. Lastly, the applications of MFC for wastewater treatment, bioelectricity generation, and biosensor development have been reviewed.
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BACKGROUND: Poultry feather waste has a potential for bioenergy production because of its high protein content. This research explored the use of chicken feather hydrolysate for methane and hydrogen production via anaerobic digestion and bioelectrochemical systems, respectively. Solid state fermentation of chicken waste was conducted using a recombinant strain of Bacillus subtilis DB100 (p5.2). RESULTS: In the anaerobic digestion, feather hydrolysate produced maximally 0.67 Nm3 CH4/kg feathers and 0.85 mmol H2/day.L concomitant to COD removal of 86% and 93%, respectively. The bioelectrochemical systems used were microbial fuel and electrolysis cells. In the first using a microbial fuel cell, feather hydrolysate produced electricity with a maximum cell potential of 375 mV and a current of 0.52 mA. In the microbial electrolysis cell, the hydrolysate enhanced the hydrogen production rate to 7.5 mmol/day.L, with a current density of 11.5 A/m2 and a power density of 9.26 W/m2. CONCLUSIONS: The data indicated that the sustainable utilization of keratin hydrolysate to produce electricity and biohydrogen via bioelectrical chemical systems is feasible. Keratin hydrolysate can produce electricity and biofuels through an integrated aerobic-anaerobic fermentation system.
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Pollos , Plumas , Animales , Anaerobiosis , Pollos/metabolismo , Hidrógeno/metabolismo , Queratinas/metabolismo , Metano/metabolismo , Biocombustibles , Reactores BiológicosRESUMEN
Microbial fuel cells (MFCs) can generate electricity by breaking down organic molecules through sustainable bio-electrochemical processes and wastewater as an energy source. A novel approach to remediate wastewater containing selenite was studied utilizing a selenite-reducing mixed bacterial culture with a nano manganese oxide modified cathode in the MFCs. The modification enhanced electrochemical catalytic activity, extracellular electron transfer rate, chemical oxygen demand (COD) elimination efficiency, and coulombic efficiency. Scanning electron microscopy and energy dispersive x-rays analysis were used to examine a manganese dioxide-coated graphite cathode's surface morphology and chemical composition. The manganese dioxide-coated electrode generated up to 69% higher voltage with 150 ppm selenite concentration than the uncoated graphite electrode. The MFC removed up to 80% of the initial COD of 120 mg l-1and achieved a maximum power density of 1.51 W m-2. The study demonstrates that MFCs can effectively treat selenite-containing wastewater, and modifying the cathode can enhance energy production.
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Fuentes de Energía Bioeléctrica , Electrodos , Compuestos de Manganeso , Óxidos , Aguas Residuales , Compuestos de Manganeso/química , Óxidos/química , Aguas Residuales/química , Purificación del Agua/métodos , Nanoestructuras/química , Ácido Selenioso/química , Ácido Selenioso/metabolismo , Análisis de la Demanda Biológica de Oxígeno , Grafito/químicaRESUMEN
With the rapid development of society, it is of paramount importance to expeditiously assess environmental pollution and provide early warning of toxicity risks. Microbial fuel cell-based self-powered biosensors (MFC-SPBs) have emerged as a pivotal technology, obviating the necessity for external power sources and aligning with the prevailing trends toward miniaturization and simplification in biosensor development. In this case, vigorous advancements in MFC-SPBs have been acquired in past years, irrespective of whether the target identification event transpires at the anode or cathode. The present article undertakes a comprehensive review of developed MFC-SPBs, categorizing them into substrate effect and microbial activity effect based on the nature of the target identification event. Furthermore, various enhancement strategies to improve the analytical performance like accuracy and sensitivity are also outlined, along with a discussion of future research trends and application prospects of MFC-SPBs for their better developments.
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Fuentes de Energía Bioeléctrica , Técnicas Biosensibles , Electrodos , Técnicas Biosensibles/métodos , Técnicas Biosensibles/instrumentaciónRESUMEN
Potassium ion signaling mediates microbial communication in electroactive biofilms within microbial fuel cells (MFCs), but its role in nitrogen removal remains unclear. This study investigated the impact of inhibiting potassium signaling on nitrogen removal in MFCs using tetraethylammonium chloride (TEA) as an inhibitor. Results demonstrated that 5 mM and 10 mM TEA reduced the maximum power generation of MFCs from 77.95 mW/cm2 to 57.18 mW/cm2 and 48.23 mW/cm2, respectively. Correspondingly, total nitrogen (TN) removal efficiency was decreased from 46.57 ± 1.01% to 35.93 ± 0.63% and 38.97 ± 0.74%, respectively. This decline was attributed to inhibited potassium ion signaling, which compromised the electrochemical performance of the MFC and hindered the nitrogen removal process. The relative abundance of exoelectrogen Geobactor decreased from 15.37% to 5.17% and 8.05%, while the relative abundance of cathodic nitrifying bacteria Nitrosomonas decreased from 17.87% to 4.92% and 3.63% under 5 mM and 10 mM TEA. These findings underscore the crucial role of potassium ion signaling in enhancing the bioelectrochemical nitrogen removal process in MFCs.
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Microbial fuel cells (MFCs) hold considerable promise for harnessing the substantial energy resources present in wastewater. However, their practical application in wastewater treatment is limited by inadequate removal of organic matter and inefficient power recovery. Previous studies have investigated aeration as a method to enhance the removal of organic matter, but this method is energy-intensive. To address this issue, this study proposed using MFC-recovered bioelectricity for aeration, thereby mitigating the associated expenses. An air-cathode MFC with multi-anode was constructed and optimized to maximize electricity supply for aeration. Carbon-felt anodes were chosen as the most effective anode configuration, due to the high abundance of electroactive bacteria and genes observed in the biofilm generated on their surface. By incorporating six carbon felt anodes, the MFC achieved a 1.7 and 1.1 fold enhancement in the maximum power and current density, respectively. The optimized MFC unit achieved a stable current density of 0.32 A/m2 and achieved COD removal of 60% in the long-term operation of 140 days in a 50 L reactor. In a reactor scaled up to 1600 L, 72 MFCs successfully powered a mini air pump work for 10 s after an 81-s charging period. The intermittent aeration resulted in partial increases in DO concentrations to 0.03-3.5 mg/L, which is expected to promote the removal of nitrogen compounds by the nitrification-anammox process. These groundbreaking results lay the foundation for self-sustaining wastewater treatment technologies.
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Fuentes de Energía Bioeléctrica , Purificación del Agua , Aguas Residuales , Electricidad , Carbono , ElectrodosRESUMEN
Microbial fuel cells (MFCs) show promise in sewage treatment because they can directly convert organic matter (OM) into electricity. This study aimed to demonstrate MFCs stability over 750 days of operation and efficient removal of OM and nitrogenous compounds from sewage. To enhance contaminant removal, oxygen was provided into the anode chamber via a mini air pump. This pump was powered by the MFCs' output voltage, which was boosted using a DC-DC converter. The experimental system consisted of 12 sets of cylindrical MFCs within a 246L-scale reactor. The boosted voltage reached 4.7 V. This voltage was first collected in capacitors every 5 min and then dispensed intermittently to the air pump for the MFCs reactor in 4 s. This corresponds to receiving average DO concentration reaching 0.34 ± 0.44 mg/L at 10 cm above the air-stone. Consequently, the degradation rate constants (k) for chemical oxygen demand (COD) and biological oxygen demand (BOD) in the presence of oxygen were 0.048 and 0.069, respectively, which surpassed those without oxygen by 0.039 and 0.044, respectively. Aeration also marginally improved the removal of ammonia because of its potential to create a favorable environment for the growth of anammox and ammonia-oxidizing bacteria such as Candidatus brocadia and Nitrospira. The findings of this study offer in-depth insight into the benefits of boosted voltage in MFCs, highlighting its potential to enhance contaminant degradation. This serves as a foundation for future research focused on improving MFCs performance, particularly for the removal of contaminants from wastewater.
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Fuentes de Energía Bioeléctrica , Aguas del Alcantarillado , Aguas del Alcantarillado/química , Aguas del Alcantarillado/microbiología , Eliminación de Residuos Líquidos/métodos , Electricidad , Contaminantes Químicos del Agua/análisis , Análisis de la Demanda Biológica de Oxígeno , Oxígeno/análisisRESUMEN
The industrial production of synthetic fertilizers and the wide-scale combustion of fossil fuels have disrupted the global nitrogen cycle, necessitating a prudent shift towards sustainable nitrogen management. Traditional wastewater treatment methods primarily focus on nitrogen elimination rather than recovery in useable form, exacerbating resource depletion and environmental degradation. This review explores integrated technologies, including bio-electroconcentration cells (BEC), direct ammonia fuel cells (DAFC), solid oxide fuel cells (SOFC), and microbial fuel cells (MFC), for effective nutrient recovery in conjugation with energy recovery. Recovered nitrogen, primarily green ammonia, offers a carbon-free energy carrier for diverse applications, including applications in DAFC and SOFC. This review underscores the importance of synchronously retrieving ammonia from wastewater and efficiently diverting it for energy recovery using an integrated fuel cell approach. The key technical challenges and future perspectives are discussed, highlighting the potential of these integrated systems to advance sustainability and circular economy goals.
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In this study, highly selenite-resistant strains belonging to Brevundimonas diminuta (OK287021, OK287022) genus were isolated from previously operated single chamber microbial fuel cell (SCMFC). The central composite design showed that the B. diminuta consortium could reduce selenite. Under optimum conditions, 15.38 Log CFU mL-1 microbial growth, 99.08% Se(IV) reduction, and 89.94% chemical oxygen demand (COD) removal were observed. Moreover, the UV-visible spectroscopy (UV) and Fourier transform infrared spectroscopy (FTIR) analyses confirmed the synthesis of elemental selenium nanoparticles (SeNPs). In addition, transmission electron microscopy (TEM) and scanning electron microscope (SEM) revealed the formation of SeNPs nano-spheres. Besides, the bioelectrochemical performance of B. diminuta in the SCMFC illustrated that the maximum power density was higher in the case of selenite SCMFCs than those of the sterile control SCMFCs. Additionally, the bioelectrochemical impedance spectroscopy and cyclic voltammetry characterization illustrated the production of definite extracellular redox mediators that might be involved in the electron transfer progression during the reduction of selenite. In conclusion, B. diminuta whose electrochemical activity has never previously been reported could be a suitable and robust biocatalyst for selenite bioreduction along with wastewater treatment, bioelectricity generation, and economical synthesis of SeNPs in MFCs.
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Fuentes de Energía Bioeléctrica , Oxidación-Reducción , Ácido Selenioso , Selenio , Selenio/metabolismo , Selenio/química , Ácido Selenioso/metabolismo , Caulobacteraceae/metabolismo , Nanopartículas/química , Electricidad , Nanopartículas del Metal/química , Consorcios Microbianos , Análisis de la Demanda Biológica de OxígenoRESUMEN
The microbial fuel cell (MFC) is considered a modern technology used for treating wastewater and recovering electrical energy. In this study, a new dual technology combining MFC and a specialized biofilter was used. The anodic materials in the system were crushed graphite, either without coating (UFB-MFC) or coated with nanomaterials (nano-UFB-MFC). This biofilter served as a barrier to retain and remove turbidity and suspended solids, while also facilitating the role of bacteria in the removal of organic pollutants, phosphates, nitrates, sulfates, oil and greases. The results demonstrated that both systems exhibited high efficiency in treating kitchen wastewater, specifically greywater and dishwashing wastewater with high detergent concentrations. The removal efficiencies of COD, oil and grease, suspended solids, turbidity, nitrates, sulfates, and phosphates in first UFB-MFC were found to be 88, 95, 89, 86, 87, 75, and 94%, respectively, and in Nano-UFB-MFC were 86, 99, 95, 91, 81, 88, and 95%, respectively, with a high efficiency in recovering bioenergy reaching a value of 1.8 and 1.5 A m-3, respectively. The results of this study demonstrate the potential for developing MFC and utilizing it as a domestic system to mitigate pollution risks before discharging wastewater into the sewer network.
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Fuentes de Energía Bioeléctrica , Filtración , Aguas Residuales , Aguas Residuales/química , Filtración/métodos , Eliminación de Residuos Líquidos/métodos , Electricidad , Biodegradación Ambiental , Purificación del Agua/métodos , Bacterias/metabolismo , Grafito/química , Contaminantes Químicos del Agua/metabolismo , ElectrodosRESUMEN
Cr (VI) is extremely harmful to both the environment and human health, and it can linger in the environment for a very long period. In this research, the Leersia hexandra Swartz constructed wetland-microbial fuel cell (CW-MFC) system was constructed to purify Cr (VI) wastewater. By comparing with the constructed wetland (CW) system, the system electricity generation, pollutants removal, Cr enrichment, and morphological transformation of the system were discussed. The results demonstrated that the L. hexandra CW-MFC system promoted removal of pollutants and production of electricity of the system. The maximum voltage of the system was 499â¯mV, the COD and Cr (VI) removal efficiency was 93.73% and 97.00%. At the same time, it enhanced the substrate and L. hexandra ability to absorb Cr and change it morphologically transformation. Additionally, the results of XPS and XANES showed that the majority of the Cr in the L. hexandra and substrate was present as Cr (III). In the L. hexandra CW-MFC system, Geobacter also functioned as the primary metal catabolic reducing and electrogenic bacteria. As a result, L. hexandra CW-MFC system possesses the added benefit of removing Cr (VI) while producing energy compared to the traditional CW system.
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Fuentes de Energía Bioeléctrica , Cromo , Aguas Residuales , Contaminantes Químicos del Agua , Humedales , Aguas Residuales/química , Eliminación de Residuos Líquidos/métodos , Biodegradación Ambiental , Hydrocharitaceae , Geobacter/metabolismo , ElectricidadRESUMEN
Multiheme cytochrome c (Cyt c) can function as a redox protein on electrode to accomplish bioelectrocatalysis. However, the direct electron transfer (DET) between the redox site of Cyt c and electrode is low due to the large coupling distance. A close proximity or a connection pathway from the deeply buried active site to the protein surface can be established by modifying the electrode with carbon nanotubes (CNTs) to improve the DET. Therefore, the isolated Cyt c has been assembled or casted with CNTs by various processes to form Cyt c-CNTs bioelectrodes that can be further applied to biosensing and bioanalysis. These strategies can be transplanted to the fabrication of biofilm-CNTs based electrodes by complexing the out membrane (OM) Cyt c of natural electricigen with CNTs to realize the application of the electrochemical properties of "in vivo" Cyt c to bioelectrochemical systems (BESs). This review intends to highlight the preparation strategies of bioelectrodes that have been well studied in electrochemical biosensors and improving approaches of the DET from the CNTs surface to Cyt c in their hybrids. The efficient fabrication processes of the biofilm-CNTs based electrodes that can be considered as "in vivo" Cyt c-CNTs based electrodes for BES designs are also summarized, aiming to provide an inspiration source and a reference to the related studies of BES downstream.
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Ácidos Alcanesulfónicos , Técnicas Biosensibles , Nanotubos de Carbono , Citocromos c/metabolismo , Nanotubos de Carbono/química , Oxidación-Reducción , ElectrodosRESUMEN
Plant microbial fuel cells (PMFCs) has important value for soil remediation and power generation. To improve the performance of PMFCs, a PMFC experimental system was established based on potted scindapsus aureus. Polyaniline (PANI) and sodium alginate (SA) were used as modifiers to prepare PANI-SA modified carbon felt anode. The soil remediation ability and electricity generation ability of PMFCs with four different anodes were compared and analyzed. The experimental results show that the steady-state voltage, the removal rate of hexavalent chromium, and the total chromium removal rate of PMFC using PANI-SA modified anode were 5.25 mV, 98%, and 90%, respectively, which are 253%, 10.4%, and 10% higher than those of PMFCs using unmodified carbon felt anode. PMFC is effective and feasible for removing soil chromium pollution and achieving efficient soil remediation, while modifying anodes with PANI-SA can further improve the soil remediation and electricity generation capabilities of PMFC.
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Compuestos de Anilina , Fuentes de Energía Bioeléctrica , Fibra de Carbono , Suelo , Carbono , Electrodos , Cromo , PlantasRESUMEN
A novel conductive composite based on PEDOT:PSS, BSA, and Nafion for effective immobilization of acetic acid bacteria on graphite electrodes as part of biosensors and microbial fuel cells has been proposed. It is shown that individual components in the composite do not have a significant negative effect on the catalytic activity of microorganisms during prolonged contact. The values of heterogeneous electron transport constants in the presence of two types of water-soluble mediators were calculated. The use of the composite as part of a microbial biosensor resulted in an electrode operating for more than 140 days. Additional modification of carbon electrodes with nanomaterial allowed to increase the sensitivity to glucose from 1.48 to 2.81 µA × mM-1 × cm-2 without affecting the affinity of bacterial enzyme complexes to the substrate. Cells in the presented composite, as part of a microbial fuel cell based on electrodes from thermally expanded graphite, retained the ability to generate electricity for more than 120 days using glucose solution as well as vegetable extract solutions as carbon sources. The obtained data expand the understanding of the composition of possible matrices for the immobilization of Gluconobacter bacteria and may be useful in the development of biosensors and biofuel cells.
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Grafito , Polímeros , Polímeros/química , Albúmina Sérica Bovina , Carbono/química , Bacterias , Glucosa/químicaRESUMEN
Biochar is a carbonaceous solid that is prepared through thermo-chemical decomposition of biomass under an inert atmosphere. The present study compares the performance of biochar prepared from Peanut shell, coconut shell and walnut shell in dual chamber microbial fuel cell. The physicochemical and electrochemical analysis of biochar reveals that prepared biochar is macroporous, amorphous, biocompatible, and electrochemically conductive. Polarization studies show that Peanut shell biochar (PSB) exhibited a maximum power density of 165 mW/m2 followed by Coconut shell biochar (CSB) Activated Charcoal (AC) and Walnut shell biochar (WSB). Enhanced power density of PSB was attributed to its surface area and suitable pore size distribution which proved conducive for biofilm formation. Furthermore, the high electrical capacitance of PSB improved the electron transfer between microbes and anode.
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Fuentes de Energía Bioeléctrica , Carbón Orgánico , Electrodos , Carbón Orgánico/química , Cocos , Juglans , Arachis , BiopelículasRESUMEN
Sustainable Cr(VI) reduction by microbial fuel cell (MFC) is a major challenge due to the electrode passivation and available electron donors. In this study, the chromate removal across a period of more than three months in a membrane-less TPBC-MFC with solid watermelon rind (SWMR) as electron donors was investigated. The TPBC benefited the Cr(VI) reduction and voltage output owing to the enhanced mass transfer. The average Cr(VI) removal efficiency (RE) of 97%, effluent COD of 80 mg/L and voltage output of 130 mV were achieved during the long-term operation on the TPBC-MFC. The SEM-EDS analysis showed that all biofilms were predominated by rod- and coccus-shaped bacteria and the Cr(VI) reduction was mainly carried out by the S-cathode. The XPS, XRD and FT-IR analysis revealed that the major product of cathodic Cr(VI) reduction was a Cr(III) precipitate in the form of Cr(OH)3. Microbial community structure disclosed that fermentation microorganisms (e.g. Anaeroarcus) and electroactive bacteria (e.g. Porphyromonadaceae) jointly responsible for SWMR degradation and electricity generation were dominant at the anode, while the chromate-associated microorganisms (e.g. Comamonadaceae and Cloacibacterium) dominated at the cathode. The biofilms adsorbing Cr(OH)3 precipitates fell off from the cathode periodically to avoid the passivation. Overall, our study suggests a really sustainable approach with which a goal of simultaneously reusing watermelon rind, reducing Cr(VI) and producing electricity was attained perfectly.
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Several previous studies concerned of microbial fuel cells integrated into constructed wetlands, nevertheless, their application as a convenient treatment for wastewater is still developing. In this experimental investigation, five CW-MFC systems were similarly designed, setup, and operated in a batch mode for two subsequent cycles. Each cycle lasted for 10 days to evaluate the performance of CW-MFC system for the remediation of real leather tannery wastewater (LTW). Four CW-MFCs were planted, each with different type of vegetation including Conocarpus, Arundo donax, Canna lily, and Cyperus papyrus in CW1-MFC, CW2-MFC, CW3-MFC, and CW4-MFC, respectively. The fifth CW5-MFC was maintained unplanted and considered as the control system. The performance of each CW-MFCs systems was evaluated mainly based on the removal of organic content (COD), total dissolved solid (TDS) elimination, and power generation. The results demonstrated that the four types of plants maintained healthy and no sign of wilting was observed during the 20 days of monitoring. For the first cycle of batch operation, maximum removal efficiencies of COD were 99.8%, 99.5%, 99.7%, 99.6% and 99.5% with power outputs of 10,502.8, 10,254.6, 9956.4, 10,029.6, and 9888.0 mW/m3, while, maximum TDS elimination were 46.7%, 39.7%, 60.8%, 55.5%, and 13.8% observed in CW1-MFC, CW2-MFC, CW3-MFC, CW4-MFC, and CW5-MFC, respectively. Very comparable results were observed in the second operation cycle. Results of phototoxicity test indicated that the germination of Hordeum vulgare and Triticum aestivum were 100% watered with treated effluent compared to 90% accomplished with tap water as the control solution for both types of seeds.
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Fuentes de Energía Bioeléctrica , Curtiembre , Eliminación de Residuos Líquidos , Aguas Residuales , Humedales , Aguas Residuales/química , Eliminación de Residuos Líquidos/métodos , Biodegradación Ambiental , Contaminantes Químicos del Agua/metabolismoRESUMEN
Integrated MFC-MBR systems effectively remove antibiotics and control the release of antibiotic resistance genes (ARGs). However, the fouling layers on membranes can potentially act as reservoirs for ARGs. This study aims to elucidate the roles of membrane fouling layers and levels in influencing sulfamethoxazole (SMX) removal and ARGs control within an MFC-MBR system. Our findings demonstrate that low-intensity bioelectricity (400-500 mV) mitigates membrane fouling rates. The membrane fouling layer significantly contributes (39%-47%) to SMX removal compared to the cathode/anode zones. Higher extracellular polymeric substance (EPS) content and a lower protein/polysaccharide (PN/PS) ratio favor SMX removal by the membrane fouling layer. Across different levels of membrane fouling, the PN/PS ratio rather than EPS concentration plays a crucial role in SMX removal efficiency. The MFC-MBR with low fouling achieved superior SMX removal (69.1%) compared to medium (54.3%) and high fouling conditions (46.8%). The presence of ARGs in the membrane fouling layer increases with fouling formation, with intrinsic ARGs prevailing. Dense membrane fouling layers effectively retain ARGs, thereby reducing the risk of extracellular ARGs (eARGs) diffusion in effluents. These results provide insights into controlling ARGs in MFC-MBR systems and underscore the significant role of membrane fouling layers in antibiotics and ARGs removal.
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Fuentes de Energía Bioeléctrica , Reactores Biológicos , Membranas Artificiales , Sulfametoxazol , Farmacorresistencia Microbiana/genética , Antibacterianos , Matriz Extracelular de Sustancias Poliméricas/metabolismoRESUMEN
Escalating global water pollution exacerbated by textile-dyeing wastewater (TDW) poses significant environmental and health concerns due to the insufficient treatment methods being utilized. Thus, it is imperative to implement more effective treatment solutions to address such issues. In this research, different environmentally-friendly strategies involving effluent recirculation (ER) and Rubia cordifolia plant-derived purpurin electron mediator (EM) were introduced to enhance the treatment of real TDW and bioelectricity generation performance of an anti-gravity flow microbial fuel cell (AGF-MFC). The results revealed that optimum performance was achieved with a combination of hydraulic retention time (HRT) of 48 h with a recirculation ratio of 1, where the reduction efficiency of biochemical oxygen demand (BOD5), chemical oxygen demand (COD), ammonium (NH4+), nitrate (NO3-), sulphate (SO42-), ammonia nitrogen (NH3-N), colour and turbidity were 82.17 %, 82.15 %, 85.10 %, 80.52 %, 75.91 %, 59.52 %, 71.02 % and 93.10 %, respectively. In terms of bioelectricity generation performance, AGF-MFC showed a maximum output voltage and power density of 404.72 mV and 65.16 mW/m2, respectively. Moreover, the results also signified that higher treatment performance of TDW was obtained with natural purpurin from Rubia cordifolia plant than synthetic purpurin as EM. The reduced reactivity of highly stable synthetic purpurin EM for mediating the electron transfer was a contributing factor to the outperformance of plant-derived purpurin. Additionally, detailed electron-mediating mechanisms of purpurin were proposed to unravel the underlying electron transfer pathway involved in AGF-MFC. This research offers insight into the development of more sustainable solutions for managing TDW, and consequently reducing environmental pollution.
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Fuentes de Energía Bioeléctrica , Rubia , Eliminación de Residuos Líquidos , Aguas Residuales , Aguas Residuales/química , Rubia/química , Eliminación de Residuos Líquidos/métodos , Textiles , Análisis de la Demanda Biológica de Oxígeno , Colorantes/químicaRESUMEN
Glyphosate (GLY), a globally-used organophosphate herbicide, is frequently detected in various environmental matrices, including water, prompting significant attention due to its persistence and potential ecological impacts. In light of this environmental concern, innovative remediation strategies are warranted. This study utilized Serratia sp. AC-11 isolated from a tropical peatland as a biocatalyst in a microbial fuel cell (MFC) coupled with a homogeneous electron-Fenton (EF) process to degrade glyphosate in aqueous medium. After coupling the processes with a resistance of 100 Ω, an output voltage value of 0.64 V was obtained and maintained stable throughout the experiment. A bacterial biofilm of Serratia sp. AC-11 was formed on the carbon felt electrode, confirmed by attenuated total reflectance-Fourier transformed infrared (ATR-FTIR) and scanning electron microscopy with energy dispersive spectroscopy (SEM-EDS). In the anodic chamber, the GLY biodegradation rate was 100% after 48 h of experimentation, with aminomethylphosphonic acid (AMPA) remaining in the solution. In the cathodic chamber, the GLY degradation rate for the EF process was 69.5% after 48 h experimentation, with almost all of the AMPA degraded by the in situ generated hydroxyl radicals. In conclusion, the results demonstrated that Serratia sp. AC-11 not only catalyzed the biodegradation of glyphosate but also facilitated the generation of electrons for subsequent transfer to initiate the EF reaction to degrade glyphosate. This dual functionality emphasizes the unique capabilities of Serratia sp. AC-11, it as an electrogenic microorganism with application in innovative bioelectrochemical processes, and highlighting its role in sustainable strategies for environmental remediation.