الفهرس 
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Abstract
The top two main crises that the world is facing nowadays are energy shortage and treatment of wastewater. A Microbial fuel cell (MFC) is a collective solution of these two crises. MFC can be utilized as green renewable energy source and eco-friendly to produce high electrical energy with simultaneous treatment. Despite the known merits, practical application of MFCs faces challenges such as high capital expenditure, low power density, sluggish extracellular electron transfer efficiency, and limited stability. To address these limitations, in this thesis, three novel developments have been achieved: 1) Commercial spacer obtained from reverse osmosis (RO) cartridge was utilized as effective high porous layer to avoid biofilm formation on the cathode surface which disconnects the membrane-less Microbial fuel cells (MFCs). 2) Synthesis effective 3D anodes graphitization of corncob and mango seed biomass at high temperature under an inert atmosphere. 3) Manufacturing of carbon nanotubes/activated carbon mixture-based cathode to replace the conventional Pt/C standard cathode to decrease the capital cost of the MFC. The performance of the two newly proposed anodes was evaluated in air‒cathode single chamber microbial fuel cell driven by domestic wastewater without using exterior microorganisms. The proposed anodes revealed very good performance in both batch and continuous modes when the process parameters were optimized. The physicochemical characterizations indicated that the surface of the prepared anodes are decorated by micro porous layers array and composed of SiO2-incorporated graphite. Moreover, investigation the electrical properties showed very good electrical conductivity dependent on the preparation temperature for the prepared anodes. The electrochemical measurements, for the batch mode cell, displayed high power density generation upon utilizing the corncob electrode compared to commercial anodes; 100±8, 135±11 and 2010±85 mW/m2 from cells assembled using carbon paper, carbon cloth and corncob‒1100 oC, respectively. Moreover, addition of sodium acetate strongly enhanced the cell performance as the generated power density was increased from 475±30 to 1963±90 mW/m2 after addition of the salt (5 g/l), however the experimental results indicated that 5 g/l is the optimum salt concentration. The evaluation of the two different 3D anodes in the real MFCs conditions established an excellent performance in term of the generated power; 2010±85 mW/m2 for corncob anode and 2170.8±90 mW/m2 for mango seed anode. Compared to standard Pt-loaded carbon cloth (Pt/C) standard cathode, the proposed carbon nanotubes/activated (CNTs/AC) cathode showed a distinguished performance with both of corncob and mango seeds anodes. Typically, the observed power densities for the proposed and Pt/C cathodes were 2010±85 and 2178.6 mW/m2, respectively in case of using corncob anode. While, in case of mango seeds, the estimated power densities were 2149.1 and 2170.5 mW/m2 for the synthesized and Pt/C electrodes, respectively. In a continuous mode, evaluation of the two introduced anodes in the real MFCs conditions established an outstanding performance in term of % chemical oxygen demand (% COD ) removal; 77% for corncob, 85% for mango seed. In a continuous mode cell, the results concluded that the generated power is higher than the batch mode system due to mass transfer resistance elimination.
Keywords: Microbial fuel cells; reverse osmosis (RO) cartridge; 3D anode; Biomass-derived electrode; Wastewater; Mango seeds; corncob; Cathode catalyst; continuous mode; batch mode.