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1.
Bioelectrochemistry ; 129: 259-269, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31247532

RESUMO

Proton-conducting porous ceramic membranes were synthesized via a polymer-derived ceramic route and probed in a microbial fuel cell (MFC). Their chemical compositions were altered by adding carbon allotropes including graphene oxide (GO) and multiwall carbon nanotubes into a polysiloxane matrix as filler materials. Physical characteristics of the synthesized membranes such as porosity, hydrophilicity, mechanical stability, ion exchange capacity, and oxygen mass transfer coefficient were determined to investigate the best membrane material for further testing in MFCs. The ion exchange capacity of the membrane increased drastically after adding 0.5 wt% of GO at an increment of 9 fold with respect to that of the non-modified ceramic membrane, while the oxygen mass transfer coefficient of the membrane decreased by 52.6%. The MFC operated with this membrane exhibited a maximum power density of 7.23 W m-3 with a coulombic efficiency of 28.8%, which was significantly higher than the value obtained using polymeric Nafion membrane. Hence, out of all membranes tested in this study the GO-modified polysiloxane based ceramic membranes are found to have a potential to replace Nafion membranes in pilot scale MFCs.


Assuntos
Fontes de Energia Bioelétrica , Cerâmica/química , Grafite/química , Membranas Artificiais , Nanotubos de Carbono/química , Siloxanas/química , Fontes de Energia Bioelétrica/microbiologia , Eletricidade , Modelos Moleculares , Porosidade
2.
Appl Microbiol Biotechnol ; 102(22): 9419-9432, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30259099

RESUMO

Conventional wastewater treatment consumes a large amount of money worldwide for removal of pollutants prior to its discharge into water body or facilitating reuse. Decreasing energy expenditure during wastewater treatment and rather recovering some value-added products while treating wastewater is an important goal for researchers. Microbial fuel cells (MFCs) are representative bioelectrochemical systems, which offer energy-efficient wastewater treatment. MFCs convert chemical energy of organic matter into electrical energy by using biocatalytic activities. Although MFCs are not truly commercialized, they have potential to make energy-gaining wastewater treatment technologies and represent their capabilities successfully. Over the last decade, MFCs have developed remarkably in almost every dimension including wastewater treatment capabilities, power output, and cost optimization; however, its architectural design is an important consideration for scaling up. Here, we review various architectural advancements and technology up-gradation MFCs have experienced during its journey, to take this technology step forward for commercialization.

3.
ACS Appl Mater Interfaces ; 10(17): 14803-14817, 2018 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-29659253

RESUMO

A hydroxyl group containing new cardo diamine monomer was synthesized, namely 9,9-bis (hydroxy- (4'-amino(3-trifluoromethyl)biphenyl-4-oxy)-phenyl)-9H-fluorene (mixture of isomers, HAPHPF). HAPHPF, along with a sulfonated diamine monomer, 4,4'-diaminostilbene-2,2'-disulfonic acid (DSDSA), was used to prepare a series of new sulfonated copolyimides by polycondensation with 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTDA). The degree of sulfonation (DS < 1) was adjusted by the feed ratio of DSDSA/HAPHPF and the copolymers were named as DHN-XX, where XX denotes the mole percentage of DSDSA (XX = 50, 60, and 70). The copolymers showed high molecular weights. The copolymer structure and composition were confirmed by FTIR and NMR techniques. Copolymer membranes were prepared through solution cast route by using dimethyl sulfoxide as a solvent. The membranes showed high thermal, mechanical, hydrolytic and peroxide radical stability, and low water uptake and low swelling ratios. Well-separated hydrophilic and hydrophobic phase morphology was observed in TEM and AFM images of the copolymer membranes and was further supported by the SAXS studies. The proton conductivity of the DHN-70 was as high as 97 mS cm-1 at 80 °C and the value is significantly higher than that of the nonhydroxylated analogue. The membranes also showed superior microbial fuel cell (MFC) performance, similar like Nafion 117 under similar test conditions. The chemical oxygen demand removal values provide substantial evidence that the fabricated membranes can be utilized in bioelectrochemical systems.

4.
Appl Biochem Biotechnol ; 183(3): 1076-1092, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28466460

RESUMO

Performance of microbial carbon capture cells (MCCs), having a low-cost clayware separator, was evaluated in terms of wastewater treatment and electricity generation using algae Chlorella pyrenoidosa in MCC-1 and Anabaena ambigua in MCC-2 and without algae in a cathodic chamber of MCC-3. Higher power production was achieved in MCC-1 (6.4 W/m3) compared to MCC-2 (4.29 W/m3) and MCC-3 (3.29 W/m3). Higher coulombic efficiency (15.23 ± 1.30%) and biomass production (66.4 ± 4.7 mg/(L*day)) in MCC-1 indicated the superiority of Chlorella over Anabaena algae for carbon capture and oxygen production to facilitate the cathodic reduction. Algal biofilm formation on the cathode surface of MCC-1 increased dissolved oxygen in the catholyte and decreased the cathodic charge transfer resistance with increase in reduction current. Electrochemical analyses revealed slow cathodic reactions and increase in internal resistance in MCC-2 (55 Ω) than MCC-1 (30 Ω), due to lower oxygen produced by Anabaena algae. Thus, biomass production in conjunction with wastewater treatment, CO2 sequestration and electricity generation can be achieved using Chlorella algal biocathode in MCC.


Assuntos
Fontes de Energia Bioelétrica/microbiologia , Biomassa , Carbono/metabolismo , Chlorella vulgaris/metabolismo , Gerenciamento de Resíduos , Águas Residuárias/química , Eletroquímica , Eletrodos , Fatores de Tempo
5.
Bioresour Technol ; 238: 568-574, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28478376

RESUMO

Application of ZrO2, MnO2, palladium, palladium-substituted-zirconium oxide (Zr0.98Pd0.02O2) and palladium-substituted-manganese oxide (Mn0.98Pd0.02O2) cathode catalysts in a single-chambered microbial fuel cell (MFC) was explored. The highest power generation (1.28W/m3) was achieved in MFC with Mn0.98Pd0.02O2 catalyst, which was higher than that with MnO2 (0.58W/m3) alone; whereas, MFC having Zr0.98Pd0.02O2 catalyzed cathode and non-catalyzed cathode produced powers of 1.02 and 0.23W/m3, respectively. Also, low-cost zirconium-palladium-composite showed better catalytic activity and capacitance over ZrO2 with 20A/m3 current production and demonstrated its suitability for MFC applications. Cyclic voltammetry analyses showed higher well-defined redox peaks in composite catalysts (Mn/Zr-Pd-C) over other catalyzed MFCs containing MnO2 or ZrO2. Electrochemical behaviour of composite catalysts on cathode showed higher availability of adsorption sites for oxygen reduction and, hence, enhanced the rate of cathodic reactions. Thus, Mn/Zr-Pd-C-based composite catalysts exhibited superior cathodic performance and could be proposed as alternatives to costly Pd-catalyst for field applications.


Assuntos
Fontes de Energia Bioelétrica , Paládio , Zircônio , Eletrodos , Manganês
6.
Appl Biochem Biotechnol ; 177(8): 1638-53, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26373945

RESUMO

Microbial desalination cell (MDC) has great potential toward direct electricity generation from wastewater and concurrent desalination through potential difference developed due to microbial activity. Degradation of phenol by isolate Pseudomonas aeruginosa in anodic chamber and simultaneous desalination of water in middle desalination chamber of multichamber MDC is demonstrated in this study. Performance of the MDCs with different anodic inoculum conditions, namely pure culture of P. aeruginosa (MDC-1), 50 % v/v mixture of P. aeruginosa and anaerobic mixed consortia (MDC-2) and anaerobic mixed consortia (MDC-3), was evaluated to compare the phenol degradation in anodic chamber, bioelectricity generation, and simultaneous total dissolved solids (TDS) removal from saline water in desalination chamber. Synergistic effect between P. aeruginosa and mixed anaerobic consortia as inoculum was evident in MDC-2 demonstrating phenol degradation of 90 %, TDS removal of 75 % in 72 h of reaction time along with higher power generation of 27.5 mW/m(2) as compared to MDC-1 (95 %, 64 %, 12.8 mW/m(2), respectively) and MDC-3 (58 %, 52 %, 4.8 mW/m(2), respectively). The results illustrate that the multichamber MDC-2 is effective for simultaneous removal of phenol and dissolved solids contained in industrial wastewaters.


Assuntos
Bactérias Anaeróbias/metabolismo , Pseudomonas aeruginosa/metabolismo , Águas Residuárias/química , Purificação da Água/métodos , Resíduos Industriais , Fenol , Resíduos Sólidos , Purificação da Água/economia
7.
Bioresour Technol ; 191: 110-6, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-25983229

RESUMO

Catalytic effect of goethite recovered from iron-ore mining mud was studied in microbial fuel cells (MFCs). Characterization of material recovered from mining mud confirms the recovery of iron oxide as goethite. Heat treated goethite (550 °C) and untreated raw goethite were coated on stainless-steel anode of MFC-1 and MFC-2, respectively; whereas, unmodified stainless-steel anode was used in MFC-3 (control). Fivefold increment in power was obtained in MFC-1 (17.1 W/m(3) at 20 Ω) than MFC-3 (3.5 W/m(3)). MFC with raw goethite coated anode also showed enhanced power (11 W/m(3)). Higher Coulombic efficiency (34%) was achieved in MFC-1 than control MFC-3 (13%). Decrease in mass-transport losses and higher redox current during electrochemical analyses support improved electron transfer with the use of goethite on anode. Cheaper goethite coating kinetically accelerates the electron transfer between bacteria and anode, proving to be a novel approach for enhancing the electricity generation along with organic matter removal in MFC.


Assuntos
Fontes de Energia Bioelétrica/microbiologia , Compostos de Ferro/química , Minerais/química , Bactérias/química , Catálise , Minas de Carvão/métodos , Eletricidade , Eletrodos/microbiologia , Elétrons , Temperatura Alta , Aço Inoxidável/química
8.
Bioresour Technol ; 182: 373-377, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25693451

RESUMO

Performance of scalable air-cathode microbial fuel cell (MFC) of 26 L volume, made from clayware cylinder with multiple electrodes, was evaluated. When electrodes were connected in parallel with 100 Ω resistance (R ext), power of 11.46 mW was produced which was 4.48 and 3.73 times higher than individual electrode pair and series connection, respectively. Coulombic efficiency of 5.10 ± 0.13% and chemical oxygen demand (COD) removal of 78.8 ± 5.52% was observed at R ext of 3 Ω. Performance under different organic loading rates (OLRs) varying from 0.75 to 6.0 g CODL(-1)d(-1) revealed power of 17.85 mW (47.28 mA current) at OLR of 3.0 g CODL(-1)d(-1). Internal resistance (R int) of 5.2 Ω observed is among the least value reported in literature. Long term operational stability (14 months) demonstrates the technical viability of clayware MFC for practical applications and potential benefits towards wastewater treatment and electricity recovery.


Assuntos
Fontes de Energia Bioelétrica , Eliminação de Resíduos Líquidos/métodos , Fontes de Energia Bioelétrica/economia , Análise da Demanda Biológica de Oxigênio , Eletrodos , Desenho de Equipamento , Eliminação de Resíduos Líquidos/instrumentação , Águas Residuárias
9.
Bioresour Technol ; 182: 225-231, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25700342

RESUMO

Waste activated sludge was digested in anodic compartment of dual chambered clayware microbial fuel cell (MFC). Performance of MFC was evaluated using oxygen (MFC-1) and hypochlorite (MFC-2) as cathodic electron acceptors. Power production of 8.7 W/m(3) was achieved using hypochlorite as catholyte, which was two times higher than using oxygen (4.2 W/m(3)). Total chemical oxygen demand of sludge was reduced by 65.4% and 84.7% in MFC-1 and MFC-2, respectively. Total and volatile suspended solids reductions were higher in MFC-2 (75.8% and 80.2%, respectively) as compared to MFC-1 (66.7% and 76.4%, respectively). Use of hypochlorite demonstrated 3.8 times higher Coulombic efficiency (13.8%) than oxygen. Voltammetric and impedance analysis revealed increase in reduction peak (from 8 to 24 mA) and decreased polarization resistance (from 42.6 to 26.5 Ω). Hypochlorite proved to be better cathodic electron acceptor, supporting rapid sludge digestion within 8 days of retention time and improved power production in MFC.


Assuntos
Fontes de Energia Bioelétrica , Ácido Hipocloroso/química , Esgotos , Impedância Elétrica , Técnicas Eletroquímicas , Microscopia Eletrônica de Varredura , Oxigênio/química
10.
Environ Technol ; 36(5-8): 767-75, 2015 Mar-Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25182800

RESUMO

Dual-chamber microbial fuel cells (MFCs), made of clayware cylinder, were operated at different chemical oxygen demands: ammonium-nitrogen (COD:NH4+) ratio (1:1, 10:1 and 5:1) under batch mode for simultaneous removal of ammonia and organic matter from wastewater. Ammonium-N removal efficiencies of 63-32.66% were obtained for COD:NH4+ ratio of 1:10, respectively. Average COD removal efficiencies demonstrated by these MFCs were about 88%; indicating effective use of MFCs for treatment of wastewater containing organic matter and high ammonia concentration. MFCs operated with COD:NH4+ ratio of 10:1 produced highest volumetric power density of 752.88 mW/m3. The ammonium-N removal slightly increased when microbes were exposed to only ammonium as a source of electron when organic source was not supplemented. When this MFC was operated with imposed potential on cathode and without aeration in the cathode chamber, oxidation of ammonium ions at a faster rate confirmed anaerobic oxidation. During the non-turnover condition of cyclic voltammetry, MFC operated with COD:NH4+ ratio of 10:1 gave higher oxidative and reductive currents than MFC operated with COD:NH4+ ratio of 1:1 due to higher redox species. Successful application of such an anammox process for ammonium oxidation in MFCs will be useful for treatment of wastewater containing higher ammonium concentration and harvesting energy in the form of electricity.


Assuntos
Compostos de Amônio/química , Fontes de Energia Bioelétrica , Purificação da Água/métodos , Aerobiose , Estudos de Viabilidade , Nitratos/química , Oxirredução
11.
Bioresour Technol ; 163: 328-34, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24835745

RESUMO

Presence of pathogenic microorganism in anodic effluent of microbial fuel cell (MFC) makes it unfit for reuse. In this study, performance of dual chamber MFC was evaluated in terms of organic matter removal, power generation and disinfection in cathodic chamber. Anodic effluent was treated further in cathodic chamber for achieving disinfection with different doses of sodium hypochlorite (NaOCl) with available chlorine varying from 0.67, 1.32, 2, 3 and 4 g/L. Addition of different doses of NaOCl resulted in satisfactory disinfection along with removal of nitrogenous compounds. Power output of MFC improved up to 3g/L of available chlorine (6.5 W/m(3)); however, further increase in chlorine concentration decreased the power. Voltammetric and impedance analysis showed higher and faster electron reduction and decrease in polarization resistance at 3g/L dose. Higher organic matter removal from wastewater and complete elimination of microorganism, along with improved power output, demonstrates effectiveness of hypochlorite as catholyte.


Assuntos
Fontes de Energia Bioelétrica , Desinfecção , Fontes de Energia Elétrica , Compostos Orgânicos/isolamento & purificação , Águas Residuárias , Purificação da Água/métodos , Análise da Demanda Biológica de Oxigênio , Eletrodos , Cinética
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