Electrode Material Optimization for Microbial Fuel Cells Using Bamboo Charcoal Powder and Bokuju

Abstract

Bamboo is a fast-growing plant in Southeast Asia, Africa, and Latin America. Due to its rapid growth, bamboo is considered a problem because it rapidly invades forested areas and alters the original ecosystem. On the other hand, it is regarded as a material that is readily available and very accessible in many countries and has great potential for both ecological and social purposes. Therefore, bamboo was employed as the material for the electrodes of microbial fuel cells in this study. Typically, biochar used for electrodes is chemically activated to remove impurities and increase its surface area. However, chemical treatment of biochar can have a negative impact on the activity of microorganisms. The Bamboo charcoal powder, prepared by heat-treating powdered bamboo for one hour under air at 500°C, contained about 75% carbon and had a porous structure. Therefore, the material could be used as an electrode material for microbial fuel cells without complicated and time-consuming treatment processes. Some of these treatment processes include chemical treatment, and chemically treated biochar may impact the environment. Bamboo charcoal, which does not require this chemical treatment process, is effective as an electrode material for microbial fuel cells. Bokuju, a common kind of drawing ink in Japan and mainly composed of carbon black, was used as a binder for the prepared bamboo charcoal. The reason for using powdered bamboo charcoal with Bokuju is that it is easier to obtain a solid electrode shape by a drying process. We used this electrode in a floating microbial fuel cell and optimized the ratio of Bamboo charcoal powder and Bokuju in the electrode. By evaluating the performance of the microbial fuel cell using the Bamboo charcoal Bokuju electrode, we were able to improve the effectiveness of the electrode material.