ABSTRACT
Microbial fuel cells (MFCs) are a novel technique for converting biodegradable materials into electricity. In this study, the efficiency of mixed crystal (TiO2:ZnO) as a membrane modifier of a low-cost, antifouling and self-cleaning cation exchange membrane for MFCs was studied. The modification was prepared using polydopamine (PDA) as the bio-inspired glue, followed by gravity deposition of a mixture of catalyst nanoparticles (TiO2:ZnO 0.03%, 1:1 ratio) as anti-biofouling agents. The effects of the membrane modification were evaluated in terms of power density, open circuit potential, coulombic efficiency, anti-biofouling properties and also color and COD removal efficiency. The results showed that the use of the PDA-modified membrane and a mixture of catalysts facilitated the transfer of cations released during the oxidation process in the anodic compartment of the MFC, which increased the power generation in the MFC by 2.5 times and 5.7 times the current compared to pristine and PDA pristine membranes, decreased the MFC operating cycle time from 5 to 3 days, doubled the lifetime of the membranes and demonstrated higher COD removal efficiency and color removal. Finally, SEM and AFM analysis showed that the modification significantly minimized surface fouling. The modified membranes in this study proved to be a potential alternative to the expensive membranes currently used in MFCs, furthermore, this modification could be an interesting alternative modification for other potential membranes for use in MFCs, due to the fact that the catalyst activation was only performed with visible light (artificial and solar), which could decrease operating costs.
Subject(s)
Bioelectric Energy Sources , Zinc Oxide , Electricity , Electrodes , Membranes, Artificial , TitaniumABSTRACT
Abstract Every year the demand for energy worldwide is increasing. There are some alternatives to reduce these problems, such as clean energy or renewable energy. A particular alternative is the microbial fuel cells. These cells are biochemical reactors that convert chemical energy into electricity. The present research evaluated the dairy serum to produce bioelectricity from micro fuel cells (MFC) that were constructed with low-cost materials and with isolated bacteria in anaerobic sediments, located in Ecuadorian national territory, producing maximum voltages of 0.830 V in the circuit and a maximum power density of 30 mW / m2. This low voltage was worked with 50 mL MFCs and with an output voltage of 300 mV. Under these conditions, a FLYBACK lift circuit isolated by the transformer was designed. This new circuit could increase the voltage from 30 mV to enough voltage to light a 2.5 V LED. Therefore, the energy produced by the MFC can be directly used to light a LED and to charge capacitors. This study shows that these MFCs, together with the designed circuit, could be used potentially to generate clean energy.
Resumen Cada año la demanda de energía, en todo el mundo, va en aumento. Existen algunas alternativas para reducir estos problemas, tales como las energías limpias y renovables. Una alternativa muy específica es el uso de celdas de combustible microbianas. Dichas celdas son reactores bioquímicos que convierten la energía química en electricidad. La presente investigación evaluó el suero lácteo para la producción de bioelectricidad en celdas de combustible microbianas (MFC). Estas fueron construidas con materiales de bajo costo y con bacterias aisladas en sedimentos anaeróbicos, ubicados en territorio nacional ecuatoriano, produciendo voltajes máximos de 0,830 V en el circuito y una densidad de potencia máxima de 30 mW / m2. Este bajo voltaje se trabajó con MFC de 50 mL y con un voltaje de salida de 300 mV. Bajo estas condiciones, se diseñó un circuito de elevación FLYBACK aislado por transformador. Este nuevo circuito aumentará el voltaje de 30 mV a un voltaje suficiente para encender un LED de 2.5 V. Por lo tanto, la energía producida por las MFC puede ser directamente utilizable para encender un LED y cargar los condensadores. Este estudio muestra que dichas celdas MFC, junto con el circuito diseñado, podrían utilizarse, potencialmente, para generar energía limpia.
Resumo Todos os anos a demanda por energia, em todo o mundo, está aumentando. Existem algumas alternativas para reduzir esses problemas, como energias limpas e renováveis. Uma alternativa muito específica é o uso de células combustíveis microbianas. Essas células são reatores bioquímicos que convertem energia química em eletricidade. O presente trabalho avaliou o soro lácteo para a produção de bioeletricidade em células a combustível microbianas (CCM), Estes foram construídos com materiais de baixo custo e bactérias isoladas em sedimentos anaeróbios, localizados no território nacional equatoriano, produzindo tensões máximas de 0,830 V no circuito e uma densidade de potência máxima de 30 mW / m2. Esta baixa voltagem trabalhamos com CCM de 50 mL e com uma voltagem de saída de 300 mV. Sob essas condições, um circuito de elevação FLYBACK isolado por transformador foi projetado. Este novo circuito aumentará a tensão de 30 mV para uma tensão suficiente para ligar um LED de 2,5 V. Portanto, a energia produzida pelo MFC pode ser diretamente utilizável para ligar um LED e carregar os capacitores. Este estudo mostra que essas células CCM, juntamente com o circuito projetado, poderiam ser usadas para gerar energia limpa.
