Comparative study in the performance of bioelectrochemical properties for microbial fuel cells
- Authors: Mphaphuli, Takalani , Du Plessis, Sydney
- Date: 2021
- Subjects: Microbial fuel cell , Wastewater , Power density
- Language: English
- Type: Journal article
- Identifier: http://hdl.handle.net/10210/493740 , uj:45119 , Citation: Mphaphuli, T. & Du Plessis, S. 2021. Comparative study in the performance of bioelectrochemical properties for microbial fuel cells.
- Description: Abstract: A microbial fuel cell is the energy harvesting technology being studied; this technology converts various substrates, water-based organic fuels, and wastewater into electrical energy by the catalytic reaction of microorganism. The research seeks to establish a comparison in the performance of bioelectrochemical properties (BEP) for microbial fuel cells (MFCs). The experiment set-up consisted of two identical MFCs; one with 30% PTFE coated carbon cloth and the other with untreated carbon cloth (AvCarb 1071HCB). Type 304 Stainless steel mesh #20 cathode electrode was used and then sectioned to a surface area of 36 cm2. Proton exchange membrane and Nafion membrane both were sectioned to a similar surface area of 36cm2. These membranes were of different thicknesses, that is; Nafion (0.05mm, 0.18mm respectively) and CMI-7000S (0.45mm thickness). The type of MFC used was the double-chamber MFC, which consisted of the anode and cathode chamber. The anode and cathode chamber were immersed in the open water bath regulated at a temperature of 350C. On the start-up, the anode chamber was fed with 800ml of municipality wastewater and 90ml of primary sludge collected from the primary clarifier effluent plant in the municipality wastewater treatment plant. On re-feeding after seven (7) days, 87.5ml (1/4 of the total solution) was removed and 87.5ml of the fresh wastewater was added at the same time and 100ml of sludge was also loaded on the anode chamber with a residence time of four (4) weeks. The coated anode (30% PTFE carbon cloth) is more efficient in generating power than the untreated anode; however, there is a limitation on the thickness of the membrane. The performance of individual membrane varies significantly with the type and thickness of the membrane and this directly affects the overall performance of MFC.
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Energy generation from full strength domestic wastewater using a sandwich dual chamber microbial fuel cell with an uncatalyzed mesh current collector cathode
- Authors: Adeniran, J.A. , De Koker, J.J. , Arotiba, O.A. , Van Zyl, E. , Du Plessis, S.
- Date: 2015
- Subjects: Microbial fuel cells , Power generation , Mesh current collector cathodes , Wastewater
- Language: english
- Type: article
- Identifier: http://hdl.handle.net/10210/15528 , uj:15671 , Adeniran, J.A. et al. 2015. Energy generation from full strength domestic wastewater using a sandwich dual chamber microbial fuel cell with an uncatalyzed mesh current collector cathode. International journal of green energy
- Description: A sandwich domestic wastewater fed dual-chamber microbial fuel cell (MFC) was designed for energy generation and wastewater treatment. Power density for the MFC increased with increasing domestic wastewater concentration, reaching a maximum of 251 mW/m2 for full strength wastewater (3400 mg/L chemical oxygen demand (COD)) at a current density of 0.054 mA/cm2 at an external resistance of 200Ω. These values dropped to 60 mW/m2 (76% lower) and 0.003 mA/cm2 using wastewater 91% diluted to 300 mg/L COD. Maximum removals were: of COD, 89%; nitrite, 60%; nitrate, 77%; total nitrogen, 36%; and phosphate, 26%.
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Enhanced removal efficiency of heavy metal ions from wastewater through functionalized silicon carbide membrane : A theoretical study
- Authors: Karimzadeh, Sina , Safaei, Babak , Jen, Tien-Chien , Oviroh, Peter Ozaveshe
- Date: 2021
- Subjects: Purification , Wastewater , Heavy metal ions
- Language: English
- Type: Journal article
- Identifier: http://hdl.handle.net/10210/490571 , uj:44768 , Citation: Karimzadeh, S., Safaei, B., Jen, T.C. and Oviroh, P.O., 2021. Enhanced removal efficiency of heavy metal ions from wastewater through functionalized silicon carbide membrane: A theoretical study. Journal of Water Process Engineering, 44, p.102413. , DOI: https://doi.org/10.1016/j.jwpe.2021.102413
- Description: Abstract: Development and designing of heavy metal ion separation systems from wastewater play a essential role in environmental protection. For this purpose, in this research, we modeled the synthetic wastewater samples and investigated the capabilities of nano-porous silicon carbide membranes (SiC) with fluorine, nitrogen, and hydroxyl-atom decorated pores under hydrostatic pressures. Increase of applied pressure on SiC with larger pore diameters had more intense effects on water flux and ion rejection. It was also found that, due to different electronic properties of decorated atoms in the edge of pores, which played important roles in their interactions with water molecules and metal ions, as well as energy barrier and permeation, water flux and ion injection were improved. The potential of mean force (PMF) calculation showed that the energy barrier for passing through functionalized pores was higher for metal ions and lower for water molecules. The presence of functional groups in the edge of SiC pores provided selective ion rejection property which was highest for Zn2+ ions. PMF analysis results proved that the PMF values of metal ions were in the following comparative order: SiC@F>SiC@N>SiC@OH>SiC. It was also observed that increase in temperature significantly increased water flux and decreased ion rejection. Also, SiC membrane separation systems improved ion rejection in the presence of electric field along the opposite direction of piston movement, which was more intense in functionalized membranes and results indicated that in voltage of 200 mV/Å had the best ion rejection of about 98%.
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