Recently microbial fuel cells (MFCs) have been considered as an alternative power generation technique by utilizing organic wastes. In this study, an experiment was carried out to generate bioelectricity from co-digestion of organic waste (kitchen waste) and sewage sludge as a waste management option using microbial fuel cell (MFC) in anaerobic process. A total of five samples with different sludge-waste ratio were used with zinc (Zn) and cupper (Cu) as cell electrodes for the test. The trends of voltage generation were different for each sample in cells such as 350 mV, 263 mV, 416 mV maximum voltage were measured from sample I, II and III respectively. It was observed that the MFC with sewage sludge showed the higher values (around 960 mV) of voltages with time whereas 918 mV obtained with organic waste. Precisely comparing cases with varying the organic waste and sewage sludge ratio helps to find the best bioelectricity generation option. Using MFCs can be appeared as the solution of electricity scarcity along the world as an efficient and eco-friendly manner as well as organic solid waste and sewage sludge management.

The study was conducted to characterize and perform laboratory-scale treatment of municipal drainage wastewater of Khulna, Bangladesh. Wastewater samples were collected from three different points of existing urban drain outlets into the Mayur River around Khulna. Laboratory testing shows the BOD 5 and COD concentration of wastewater samples varied from 57-226 mg/l and 320-435 mg/l, respectively, and the total dissolved solids ranged from 1800-2525 mg/l. Therefore, a laboratory-scale treatment technology was developed to treat this wastewater. Treatment technologies adopted were primary sedimentation, followed by aeration, chemical precipitation and filtration. In treated wastewater, BOD 5 , COD and TDS were found to be in the range of 40-115 mg/l, 160-256 mg/l and 1356-1500 mg/l, respectively. These test results suggest that the performance of laboratory-scale treatment plant was not adequate to fulfil the acceptable limit (ECR'97) for safe disposal into surface water bodies. Due to poor quality of effluents, modification of laboratory-scale treatment plant was made by an activated sludge process followed by granular media filtration. The final BOD 5 , COD TDS and TSS concentration of effluents was found to be 1.38-9.8 mg/l, 32-192 mg/l, 590-1667 mg/l, and 35-95 mg/l respectively, which satisfy ECR'97 standard limits for safe disposal into inland water bodies.

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