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1.
Chemosphere ; 254: 126926, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32957303

RESUMO

In less than a decade, bioelectrochemical systems/microbial fuel cell integrated constructed wetlands (electroactive wetlands) have gained a considerable amount of attention due to enhanced wastewater treatment and electricity generation. The enhancement in treatment has majorly emanated from the electron transfer or flow, particularly in anaerobic regions. However, the chemistry associated with electron transfer is complex to understand in electroactive wetlands. The electroactive wetlands accommodate diverse microbial community in which each microbe set their own potential to further participate in electron transfer. The conductive materials/electrodes in electroactive wetlands also contain some potential, due to which, several conflicts occur between microbes and electrode, and results in inadequate electron transfer or involvement of some other reaction mechanisms. Still, there is a considerable research gap in understanding of electron transfer between electrode-anode and cathode in electroactive wetlands. Additionally, the interaction of microbes with the electrodes and understanding of mass transfer is also essential to further understand the electron recovery. This review mainly deals with the electron transfer mechanism and its role in pollutant removal and electricity generation in electroactive wetlands.


Assuntos
Fontes de Energia Bioelétrica , Eletricidade , Transporte de Elétrons , Águas Residuárias , Purificação da Água/métodos , Áreas Alagadas , Eletrodos , Microbiota , Águas Residuárias/análise , Águas Residuárias/microbiologia
2.
Sci Total Environ ; 738: 140138, 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-32806344

RESUMO

An understanding of the inter-species relationships, especially their metabolic network in a mixed-culture system, is crucial to design an effective inoculum for enhancing the power generation of wastewater fed microbial fuel cell (MFC). In the present study, the influence of microbial mutualistic interactions on the power generation of palm oil mill effluent fed MFCs has been widely investigated by designing several co-culture and mixed culture inoculums. Among the different inoculum compositions, the highest power density of 14.8 W/m3 was achieved by Pseudomonas aeruginosa and Klebsiella variicola co-culture inoculum due to their synergistic relationships which were inter-linked via fermentation-based metabolites. Besides, the interaction of K. variicola and Bacillus cereus positively influenced the power generation resulting in a maximum power density of 11.8 W/m3 whereas the antagonistic relationship between B. cereus and P. aeruginosa resulted in a lower power generation of 1.9 W/m3. The microbial mutualistic interactions were investigated with polarization, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), as well as by using metabolite and biofilm analysis. It was observed that the synergism between bacteria enhanced power generation through the production of higher electron shuttling mediators and efficient biofilm formation as evidenced by polarization, CV and EIS analysis. In contrast, the antagonistic relationship resulted in production of cell inhibiting metabolites leading to the formation of ineffective biofilm. These findings demonstrate that the synergistic interaction between or within microorganisms is emergent in designing co-culture or mixed-culture inoculum for achieving maximum power generation in MFCs.


Assuntos
Fontes de Energia Bioelétrica , Técnicas de Cocultura , Klebsiella , Interações Microbianas , Águas Residuárias
3.
Environ Pollut ; 265(Pt B): 115084, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32806463

RESUMO

The effects of the continuous accumulation of Zinc (Zn) on the fate of antibiotic resistance genes (ARGs) in constructed wetland-microbial fuel cells (CW-MFCs) remain unclear. In this study, the impacts of Zn addition and a circuit mode on antibiotic removal, occurrence of ARGs, the bacterial community, and bacterial functions were investigated in three groups of CW-MFCs. The results showed that continuous Zn exposure enriched the target ARGs during the initial stage, while excessive Zn accumulation decreased antibiotic removal and the abundance of ARGs. A principal component analysis demonstrated that ARGs and the bacterial community distribution characteristics were significantly impacted by the mass accumulation of antibiotics and Zn, as well as the circuit mode. A redundancy analysis, partial least squares path modeling, and Procrustes analysis revealed that the accumulation of antibiotics and Zn, the composition of the bacterial community, the circuit mode, and the abundance of intI associated with horizontal gene transfer jointly contributed to the distributions of ARGs in the electrodes and effluent. Moreover, continuous exposure to Zn decreased the bacterial diversity and changed the composition and function of the bacterial community predicted using PICRUSt tool. The co-occurrence of ARGs, their potential hosts and bacterial functions were further revealed using a network analysis. A variation partition analysis also showed that the accumulation of target pollutants and the circuit mode had a significant impact on the bacterial community composition and functions. Therefore, the interaction among ARGs, the bacterial community, bacterial functions, and pollutant accumulations in the CW-MFC was complex. This study provides useful implications for the application of CW-MFCs for the treatment of wastewater contaminated with antibiotics and heavy metals.


Assuntos
Fontes de Energia Bioelétrica , Antibacterianos/farmacologia , Resistência Microbiana a Medicamentos/efeitos dos fármacos , Genes Bacterianos/efeitos dos fármacos , Áreas Alagadas , Zinco
4.
J Environ Sci (China) ; 96: 1-20, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32819684

RESUMO

Over half of century, sanitary landfill was and is still the most economical treatment strategy for solid waste disposal, but the environmental risks associated with the leachate have brought attention of scientists for its proper treatment to avoid surface and ground water deterioration. Most of the treatment technologies are energy-negative and cost intensive processes, which are unable to meet current environmental regulations. There are continuous demands of alternatives concomitant with positive energy and high effluent quality. Microbial fuel cells (MFCs) were launched in the last two decades as a potential treatment technology with bioelectricity generation accompanied with simultaneous carbon and nutrient removal. This study reviews capability and mechanisms of carbon, nitrogen and phosphorous removal from landfill leachate through MFC technology, as well as summarizes and discusses the recent advances of standalone and hybrid MFCs performances in landfill leachate (LFL) treatment. Recent improvements and synergetic effect of hybrid MFC technology upon the increasing of power densities, organic and nutrient removal, and future challenges were discussed in details.


Assuntos
Fontes de Energia Bioelétrica , Eliminação de Resíduos , Poluentes Químicos da Água , Nitrogênio , Instalações de Eliminação de Resíduos
5.
J Environ Sci (China) ; 96: 171-177, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32819691

RESUMO

Microbial fuel cells (MFC) utilize microbes as catalysts to convert chemical energy to electricity. Inocula used for MFC operation must therefore contain active microbial population. The dye reduction-based electron-transfer activity monitoring (DREAM) assay was employed to evaluate different inocula used in MFCs for their microbial bioelectrical activity. The assay utilizes the redox property of Methylene Blue to undergo color change from blue to colorless state upon microbial reduction. The extent of Methylene Blue reduction was denoted as the DREAM assay coefficient. DREAM assay was initially performed on a microbial culture along with the growth curve and estimation of colony forming units (CFUs). DREAM coefficient correlated to the CFU/mL obtained over time as growth progressed. The assay was then extended to water samples (domestic sewage, lake and a man-made pond) serving as inocula in MFCs. Domestic wastewater gave the highest DREAM coefficient (0.300 ± 0.05), followed by pond (0.224 ± 0.07) and lake (0.157 ± 0.04) water samples. Power density obtained conformed to the DREAM coefficient values, with the three samples generating power densities of 46.45 ± 5.1, 36.12 ± 3.2 and 25.08 ± 4.3 mW/m2 respectively. We have also studied the role of addition of various carbon sources and their concentrations towards improving the sensitivity of the assay. The DREAM assay is a rapid, easy-to-perform and cost-effective method to assess inocula for their suitability as anolytes in terms of electron transfer potential in MFCs.


Assuntos
Fontes de Energia Bioelétrica , Corantes , Eletricidade , Eletrodos , Elétrons , Oxirredução , Águas Residuárias
6.
Bioresour Technol ; 316: 123928, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32768999

RESUMO

A novel tubular-type photosynthetic microbial fuel cell (PMFC) with algal growth and multiple electrodes in the cathode chamber was operated at various hydraulic retention times (HRTs). When the HRT in the cathode was fixed to 24 h, cell voltage gradually increased as the HRT in the anode was decreased from 24 h to 6 h, and at 6 h, 315 mV of electricity was generated and the dissolved oxygen concentration was 10.31 ± 2.60 mg/L. However, HRT changes in the cathode did not affect cell voltage generation much, although a sharp decrease in cell voltage was observed at 2-h HRT. With wastewater passing through the chambers in series (19.3-h total HRT), the PMFC was able to successfully generate cell voltage and remove nutrients. The maximum COD and phosphorus removal percentages were obtained for an initial COD of 300 mg/L, while the maximum nitrogen removal was obtained for an initial COD of 400 mg/L.


Assuntos
Fontes de Energia Bioelétrica , Carbono , Eletricidade , Eletrodos , Águas Residuárias
7.
Bioresour Technol ; 316: 123919, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32771939

RESUMO

Ferricyanide is often used in microbial fuel cells (MFCs) to avoid oxygen intrusion that occurs with air cathodes. However, MFC internal resistances using ferricyanide can be larger than those with air cathodes even though ferricyanide results in higher power densities. Using a graphite fiber brush cathode and a ferricyanide catholyte (FC-B) the internal resistance was 62 ± 4 mΩ m2, with 84 ± 8 mΩ m2 obtained using ferricyanide and a flat carbon paper cathode (FC-F) and only 51 ± 1 mΩ m2 using a 70% porosity air cathode (A-70). The FC-B MFCs produced the highest maximum power density of all configurations examined: 2.46 ± 0.26 W/m2, compared to 1.33 ± 0.14 W/m2 for the A-70 MFCs. The electrode potential slope (EPS) analysis method showed that electrode resistances were similar for ferricyanide and air-cathode MFCs, and that higher power was due to the larger experimental working potential (500 ± 12 mV) of ferricyanide compared to the air cathode (233 ± 5 mV).


Assuntos
Fontes de Energia Bioelétrica , Eletricidade , Eletrodos , Elétrons , Oxidantes , Oxigênio
8.
Environ Pollut ; 266(Pt 2): 115373, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32827985

RESUMO

Effective utilization of harmful algal biomass from eutrophic lakes is required for sustainable waste management and circular bioeconomy. In this study, Microcystis aeruginosa derived biomass served as an electron donor in the microbial fuel cell (MFC) for waste treatment and electricity generation. Bioelectrochemical performance of MFC fed with microalgae (MFC-Algae) was compared with MFC fed with a commercial substrate (MFC-Acetate). Complete removal of microcystin-LR (MC-LR) and high chemical oxygen demand (COD) removal efficiency (67.5 ± 1%) in MFC-Algae showed that harmful algal biomass could be converted into bioelectricity. Polarization curves revealed that MFC-Algae delivered the maximum power density (83 mW/m2) and current density (672 mA/m2), which was 43% and 45% higher than that of MFC-Acetate respectively. Improved electrochemical performance and substantial coulombic efficiency (7.6%) also verified the potential use of harmful algal biomass as an alternate MFC substrate. Diverse microbial community profiles showed the substrate-dependent electrogenic activities in each MFC. Biodegradation pathway of MC-LR by anodic microbes was also explored in detail. Briefly, a sustainable approach for on-site waste management of harmful algal biomass was presented, which was deprived of transportation and special pretreatments. It is anticipated that current findings will help to pave the way for practical applications of MFC technology.


Assuntos
Fontes de Energia Bioelétrica , Gerenciamento de Resíduos , Análise da Demanda Biológica de Oxigênio , Biomassa , Eletricidade , Eletrodos , Águas Residuárias
9.
Sci Total Environ ; 745: 141163, 2020 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-32736116

RESUMO

The improvement of cathode performance has always been the bottleneck and research hot spot for microbial fuel cells (MFCs). An Fe3O4@NiFe-LDH composite with a nanoscale core-shell structure containing an Fe3O4 magnetic core and a layered double hydroxide (LDH) shell was prepared by the hydrothermal method. The Fe3O4@NiFe-LDH was characterized by FT-IR, XRD, SEM and EDS. The characterization results showed that the composite had a unique cauliflower-like nanoflake structure and special pore size distribution, which greatly improved the ORR performance. Moreover, the use of the synthesized Fe3O4@NiFe-LDH core-shell structure as an electrode in an MFC was characterized by CV and LSV, which showed that the Fe3O4@NiFe-LDH exhibited excellent ORR catalytic properties. The voltage output of the Fe3O4@NiFe-LDH MFC was maintained at approximately 0.39 V, with insignificant variations over 110 h. The maximum power density was 211.40 ± 2.27 mW/m2, which was 34 times that of the blank control group MFC and was caused by the many electroactive sites, good rate capability and remarkable cycling stability of LDH. This study provides the possibility for using Fe3O4@NiFe-LDH in cathodes to operate continuously and at low cost in fuel cells.


Assuntos
Fontes de Energia Bioelétrica , Eletrodos , Hidróxidos , Ferro , Níquel , Espectroscopia de Infravermelho com Transformada de Fourier
10.
Water Sci Technol ; 81(9): 1972-1982, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32666950

RESUMO

This study evaluated the effects of temporary external voltage on the performance of two-chambered microbial fuel cells (MFC) that use nitrate wastewater as a substrate. Results indicate that the external voltage affected the performance of the MFC during their operation, and this effect remained even after the voltage was removed. The degradation efficiency of the chemical oxygen demand increased in the MFC under external voltages of 0.5, 0.8, and 1.1 V, and the optimal applied voltage was 1.1 V. Compared with the control group without external voltages, the MFC under a voltage of 1.1 V achieved higher current densities and efficiency of nitrate removal during their operation. The MFC with an applied voltage of 1.1 V also achieved the highest maximum power density of 2,035.08 mW/m3. The applied voltages of 0.5 and 0.8 V exerted a positive effect on the performance of the MFC. High-throughput sequencing was used to explore the anode and cathode biofilms. Results showed that the influence was highly associated with microbial community in bio-anode. The predominant functional family changed from Methanotrichaceae during start-up to Flavobacteriaceae in a steady phase.


Assuntos
Fontes de Energia Bioelétrica , Biofilmes , Análise da Demanda Biológica de Oxigênio , Eletricidade , Eletrodos , Águas Residuárias
11.
Bioresour Technol ; 315: 123795, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32659424

RESUMO

Hydrogen production from Saccharina Japonica by simultaneous dark fermentation (DF) and microbial electrolysis cell (MEC), called sDFMEC, was studied. In the novel sDFMEC process, substrates were converted to H2 and volatile fatty acids (VFAs) by DF in the bulk phase, and VFAs are simultaneously oxidized by the exoelectrogens in the microbial film on anode electrode with further production of H2 at the cathode. The sDFMEC process was compared with DF and a combined process of DF and MEC in series (DF-MEC) in terms of H2 production. The overall H2 production from S. Japonica in sDFMEC process was higher (438.7 ± 13.3 mL/g-TS), than DF (54.6 ± 0.8 mL/g-TS) and DF-MEC (403.5 ± 7.9 mL/g-TS) process, respectively, which is approximately 3-times higher than those reported in the literature.


Assuntos
Fontes de Energia Bioelétrica , Alga Marinha , Eletrólise , Ácidos Graxos Voláteis , Fermentação , Hidrogênio
12.
Water Sci Technol ; 81(7): 1336-1344, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32616686

RESUMO

The microbial fuel cell (MFC) provides new opportunities for energy generation and wastewater treatment through conversion of organic matter into electricity by electrogenic bacteria. This study investigates the effect of different types and concentrations of substrates on the performance of a double chamber microbial fuel cell (DCMFC). Three mediator-less laboratory-scale DCMFCs were used in this study, which were equipped with graphite electrode and cation exchange membrane. The MFCs were fed with three different types of substrates (glucose, acetate and sucrose) at a chemical oxygen demand (COD) concentration of 1,000 mg/L. The selected substrate (acetate) was studied for three different concentrations of 500, 2,000 and 3,000 mg/L of COD. Results demonstrated that acetate was the best substrate among the three different substrates with maximum power density and COD removal of 91 mW/m2 and 77%, respectively. Concentration of 2,000 mg/L was the best concentration in terms of performance with maximum power density and COD removal of 114 mW/m2 and 79%, respectively. The polarization curve shows that ohmic losses were dominant in DCMFCs established for all three substrates and concentrations.


Assuntos
Fontes de Energia Bioelétrica , Análise da Demanda Biológica de Oxigênio , Eletricidade , Eletrodos , Águas Residuárias
13.
Bioresour Technol ; 314: 123744, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32615443

RESUMO

This study investigated synthetic wastewater treatment under low inflow C/N ratio and characterized NO3--N-transforming and electricity-producing bacteria in a multi-anode tidal constructed wetland-microbial fuel cell (TFCW-MFC). The optimal concurrent average removal rates of NH4+-N and NO3--N were 73% and 78%, respectively, under a flood/rest/flood time of 4 h/2h/4h in "tide" mode accompanied by one recirculation. The lowest NO3--N concentration among all anodes was observed when the electrode gap was 45 cm. Similarly, the 45 cm anode exhibited selective enrichment of Variovorax and Azoarcus. Correction analysis showed that the high relative abundance of Azoarcus was crucial in enhancing NO3--N removal, and the internal resistance significantly decreased as the relative abundance of Acidovorax increased. These results suggest that NO3--N removal and bioelectricity generation can be promoted in a TFCW-MFC with limited carbon by improving the culture conditions for specific genera.


Assuntos
Fontes de Energia Bioelétrica , Carbono , Eletricidade , Eletrodos , Nitratos , Águas Residuárias , Áreas Alagadas
14.
Bioresour Technol ; 314: 123808, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32713782

RESUMO

Constructed wetland-microbial fuel cells (CWL-MFCs) are eco-friendly and sustainable technology, simultaneously implementing contaminant removal and electricity production. According to intensive research over the last five years, this review on the operation mechanism was conducted for in-depth understanding and application guidance of CWL-MFCs. The electrochemical mechanism based on anodic oxidation and cathodic reduction is the core for improved treatment in CWL-MFCs compared to CWLs. As the dominant bacterial community, the abundance and gene-expression patterns of electro-active bacteria responds to electrode potentials and contaminant loadings, further affecting operational efficiency of CWL-MFCs. Plants benefit COD and N removal by supplying oxygen for aerobic degradation and rhizosphere secretions for microorganisms. Multi-electrode configuration, carbon-based electrodes and rich porous substrates affect transfer resistance and bacterial communities. The possibilities of CWL-MFCs targeting at recalcitrant contaminants like flame retardants and interchain interactions among effect components need systematic research.


Assuntos
Fontes de Energia Bioelétrica , Eletricidade , Eletrodos , Águas Residuárias , Áreas Alagadas
15.
J Environ Manage ; 270: 110826, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32721300

RESUMO

Microbial fuel cell (MFC) technology has emerged as a new and attractive bioelectrochemical approach in the last one and a half decade that offers an alternative to conventional treatment methods to remove and recover heavy metals and organics from wastewaters with simultaneous energy production. This technique has advantage over the conventional wastewater treatment techniques, which are energy intensive, sludge producing and with little effectivity at high concentrations. Significant work has been done in the recent years on MFC principle, electrode configuration, biofilm composition, application of MFC in wastewater treatment, metal removal or recovery and energy production. Basically, metal in the cathode chamber acts as acceptor of the electrons released from the oxidation of organic matter in the anode chamber by electrogenic microbes. Literature shows that efficacy of MFCs in removal and recovery of metals and power production is significantly influenced by redox potential of the metal, initial concentration, mix metal systems, carbon source in substrate, pH, biocathode, biofilm composition, gaseous environment in cathode, electrode modification and external resistance, which have been critically reviewed for the first time in the present paper to understand the role of the determinant factors that may be explored for improvement of the MFC performance. The paper provides further insights into the techno-economic aspects of MFC technology and suggests research needs for enhanced performance and reduced costs to increase its feasibility for application at commercial level.


Assuntos
Fontes de Energia Bioelétrica , Metais Pesados , Eletricidade , Eletrodos , Esgotos , Águas Residuárias
16.
Environ Sci Pollut Res Int ; 27(29): 36075-36084, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32613514

RESUMO

Combination of the treatment of effluents with high organic loads and the production of electricity is the driving forces stimulating the development of microbial fuel cells (MFC). The increase in electricity production in MFCs requires not only the optimization of the operational parameters but also the inhibition of the metabolic pathways, which compete with electricity production, such as methanogenesis. The presence of both sulphate and sulphide ions in conventional anaerobic reactors hampers the growth of methanogenic archaea and justifies the use of sulphate and therefore sulphate-reducing bacteria (SRB) in the anodic half-cell of MFC. Most importantly, the literature on the subject reveals that SRB are able to directly transfer electrons to solid electrodes, enabling the production of electrical energy. This technology is versatile because it associates the removal of both sulphate and the chemical oxygen demand (COD) with the production of electricity. Therefore, the current work revises the main aspects related to the inoculation of MFC with SRB focusing on (i) the microbial interactions in the anodic chamber, (ii) the electron transfer pathways to the solid anode, and also (iii) the sulphate and COD removal yields along with the electricity production efficiencies.


Assuntos
Fontes de Energia Bioelétrica , Eletricidade , Eletrodos , Oxirredução , Sulfatos , Águas Residuárias
17.
Environ Pollut ; 266(Pt 2): 115154, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32650205

RESUMO

The insufficient removal of pollutants and bioelectricity production have become a bottleneck for high-concentration saline wastewater treatment through microbial fuel cell (MFC) technology. Herein, a novel supercapacitor MFC (SC-MFC) was constructed with carbon nanofibers composite electrodes to investigate pollutant removal ability, power generation, and electrochemical properties using real landfill leachate. The possible extracellular electron transfer and nitrogen element conversion pathways in the bioanode were also analyzed. Results showed that the SC-MFC had higher pollutant removal rates (COD: 59.4 ± 1.2%; NH4+-N: 78.2 ± 1.6%; and TN: 77.8 ± 1.2%), smaller internal impedance Rt (∼6 Ω), higher exchange current density i0 (2.1 × 10-4 A cm-2), and a larger catalytic current j0 (704 µA cm-2) with 60% leachate than those with 10% and 20% leachate, resulting in a power output of 298 ± 22 mW m-2. Ammonium could be incorporated by chemoautotrophic bacteria to produce organic compounds that could be further utilized by heterotrophs to generate power when biodegradable organic matters are depleted. Three conversion pathways of nitrogen might be involved, including NH4+ diffusion from anode to cathode chamber, nitrification, and the denitrification process. Additionally, cyclic voltammetry tests showed that both the direct electron transfer (DET) and the mediator electron transfer in bioanode were involved and dominated by DET. The microbial analysis revealed that the bioanode was dominated by salt-tolerant denitrifying bacteria (38.5%), which was deduced to be the key functional microorganism. The electrochemically active bacteria decreased significantly from 61.7% to 4% over three stages of leachate treatment. Overall, the SC-MFC has demonstrated the potential for wastewater treatment along with energy harvesting and provides a new avenue toward sustainable leachate management.


Assuntos
Fontes de Energia Bioelétrica , Desnitrificação , Eletricidade , Eletrodos , Nitrificação , Nitrogênio , Águas Residuárias
18.
Sci Total Environ ; 743: 140738, 2020 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-32673918

RESUMO

Systems with catalytic cathode in microbial fuel cell can achieve high treatment efficiency enhanced by the cathode. Such bio-electrochemical systems have potential applications in treating high-salinity nitrogenous mariculture wastewater. For sustainable development of the mariculture industry, enhancing inorganic nitrogen removal is of vital importance due to the low carbon to nitrogen (C/N) ratio of wastewater and strict discharge standard. Herein, simulated mariculture wastewater (high salinity, low COD/N ratio of 0.5-1.0) was successfully treated in an integrated self-biased bio-electrochemical system, with catalyst (TiO2/Co-WO3/SiC) on the cathode and natural-grown algae in the cathode chamber. Satisfactory nitrogen removal (94.05% NH4+-N and 77.35% inorganic nitrogen) and favorable 76.66% removal of organics (UV254) were both achieved, with visible light illumination. The NH4+-N in the effluent was below 2 mg L-1. The synergy of bacteria, algae and cathode, promoted pollutant removal, and made the system sustainable and efficient in treating mariculture wastewater.


Assuntos
Fontes de Energia Bioelétrica , Águas Residuárias , Catálise , Desnitrificação , Eletrodos , Nitrogênio
19.
Chemosphere ; 260: 127593, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32679377

RESUMO

In this study we demonstrate Sulphonated Polyhedral oligomeric silsesquioxane (S-POSS) incorporated Sulphonated Poly Ether Ether Ketone (SPEEK) as an effective cation exchange membrane (CEM) for improving performance and sustainability in a fabricated tubular Microbial Fuel Cell (MFC). The organic-inorganic caged frame of S-POSS enables several ion conducting channels thereby resulting in better proton conductivity and water uptake in addition to hydroxide ions native in POSS. Among the membranes, SPEEK+ 5 wt% S-POSS exhibits a highest maximum performance of 162 ± 1.4 mW m-2 with the highest IEC of 1.8 ± 0.05 meq g-1. Microbial community analysis reveals the predominance of several bacterial strains contributing to wide range of mechanisms. Three phyla including Betaproteobacteria, Gammaproteobacteria and Firmicutes showed maximum predominance. In addition to a novel nanocomposite membrane, the present research introduces perceptions of two metabolic mechanisms of the microbial community available which opens pathway for future insights on how other miniatures involve in electron transfer mechanisms.


Assuntos
Fontes de Energia Bioelétrica/microbiologia , Cetonas/química , Membranas Artificiais , Nanocompostos/química , Compostos de Organossilício/química , Polietilenoglicóis/química , Ácidos Sulfônicos/química , Condutividade Elétrica
20.
Bioresour Technol ; 311: 123588, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32475794

RESUMO

The proper treatment of swine wastewater with relatively high concentrations of antibiotics is very important to protect environmental safety and human health. Microbial fuel cell (MFC) technology shows much promise for removing pollutants and producing electricity simultaneously. A double-chamber MFC was investigated in this study. Synthetic swine wastewater with the addition of sulfonamides was used as the fuels in the anode chamber. Results indicated that COD could be effectively removed (>95%) and virtually not affect by the presence of sulfonamides in the MFC. A stable voltage output was also observed. The removal efficiencies of sulfamethoxazole (SMX), sulfadiazine (SDZ), and sulfamethazine (SMZ) in the MFC were in the 99.46-99.53%, 13.39-66.91% and 32.84-67.21% ranges, respectively. These totals were higher than those reported for a traditional anaerobic reactor. Hence, MFC revealed strong resistance to antibiotic toxicity and high potential to treat swine wastewater with antibiotics.


Assuntos
Fontes de Energia Bioelétrica , Águas Residuárias , Animais , Antibacterianos , Eletricidade , Eletrodos , Sulfametoxazol , Suínos
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