Application of Different Organic Wastes for Electricity Generation by Means of Double Chambered Microbial Fuel Cell Technology

Abstract

Wastes generated by both agrobased industries and domestic units have high nutrient contents to support microbial growth but in Nigeria, these wastes are indiscriminately dumped and constitutes environmental and health hazards. Some of these wastes can be used to grow some bacterial species in microbial fuel cell to generate bioelectricity. The waste materials used in this work are, banana, and pineapple peels. Glucose was used for comparison. Bacterial species used were isolated from fluids collected from dustbins and soil, all within Chukwuemeka Odumegwu Ojukwu University, Uli campus. Microscopic characterization of the isolates by Grams reaction revealed the isolate to be Gram negative and Spore test were negative. Biochemical tests showed that the isolate were catalase positive, oxidase negative and citrate positive. By Bergys criteria, the isolate was shown to be Pseudomonas species. Genetic characterization confirmed the species to be Pseudomonas aeruginosa. Four (4) MFC's were fabricated with a liter transparent plastic for the anode and cathode poles. The electrodes used was graphite for the production of graphite-graphite fuel cells. A 3.75% Sodium chloride, 2.2% agar salt bridge connected the chambers. Glucose, banana and pineapple peels were used as organic substrates and pure cultures of Pseudomonas aeruginosa were biocatalyst for the fuel cells. Result for effect of aeration with Pseudomonas aeruginosa by multimetric monitoring gave maximum power of 3.983 X 10 -4 W, 7.1625 X 10 -4 W and 8.9920 X 10 -4 W for glucose, banana peel and pineapple peel respectively, while non-aeration was 3.936 X 10 -4 W, 7.059 X 10 -4 W and 8.909 X 10 -4 W for glucose, banana peel and pineapple peel. Population growth determination by spectrophotometric method at wavelength 540 nm gave these results 1.148, 1.572, 1.714 and 1.837 with Pseudomonas aeruginosa on days 1, 4, 7 and 10 respectively.