Development of Microbial Fuel Cell for Palm Oil Mill Effluent Treatment

Microbial fuel cells (MFCs) are a device that utilises microorganisms as a biocatalyst, to oxidize organic and inorganic matters to generate electric current. The main purpose of this study was to evaluate laboratory scale MFC which was inoculated with sludge containing mixed culture grown in palm oil mill effluent (POME). This work also aimed to construct a suitable design of MFC and to observe mixed culture activation that could lead to electric power production. POME was used in diluted form with COD concentration of 3750 mg-COD L-1. The performance of power generation and the efficiency of waste-water treatment in term of COD, nitrogen and total carbohydrate removal, in dual chamber MFC were recorded and analysed everyday for 15 days. The plots between experimental data and polarization model fit well and are able to describe the ability of power density generated in each day. Power density increased from 1.607 mW m(-2) (3.816 mA m(-2)), in the first day of the experiments to a maximum value on the third day 1.979 mW m(-2) (4.780 mA m(-2)) and then slowed down in day seventh to a minimum value of 1.311 mW m(-2) (3.346 mA m(-2)). The removal efficiency in MFC could be divided into three different levels. The first level is in term of poor efficiency although the power was increasing, while in the second level, the efficiency was getting higher and finally in third level, power production of MFC started to diminish. The highest efficiency occurs during the third level when steady power generation took place at certain level. The treatment efficiency in term of COD removal, nitrogen and carbohydrate utilization at day 15th were 54.9, 100 and 98.9%, respectively. The relationship between electricity power generation and treatment efficiency was successfully modelled into linear equation based on the respective power generation levels.