Agric & Bioresources Engineering

Permanent URI for this collectionhttp://197.211.34.35:4000/handle/123456789/72

Agric & Bioresources Engineering

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Author: search.filters.author.Freitag, Ruth

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    The applicability of the Maximum Power-point of Microbial Fuel Cells: Influence of Potential Scan rate and real-time external Load
    (international Society for microbial Electrochemistry amd Technology-ISMET, 2021-09-15) Simeon, Meshack Imologie; Freitag, Ruth
    Performance evaluation of a microbial fuel cell (MFC) is usually done with linear sweep voltammetry (LSV) [1] at a given potential scan rate (PSR) [2]. This evaluation does not often reflect the long-term performance of the MFC under real-time external loads [1]. In this study, the performance of a single-chamber MFC was evaluated with three external loads (1206, 470, and 270 Ohms) calculated from LSV maximum power point (MPP) with three PSRs (0.1, 0.5, and 1 mV/s). The estimated power from the MPP in ascending order of PSR was 61.96, 87.88, and 166.68 mW/m2 at 116.5, 229.6, and 403 mA/m2, respectively. The average power obtained with 1206, 470, and 270 Ohms in the first two hours of operation was 73 + 16.7, 36.3 + 42, and 88.5 + 120.1 mW/m2 at current densities of 124.6 + 14.3, 121.2 + 73.4, and 232.6 + 176.2 mA/m2, respectively. The result showed that overestimation was more pronounced at higher PSRs. Although the MFC was initially underestimated at 0.1 mV/s, this PSR more accurately reflects the true and applicable estimate of the long-term performance of the MF vC. These results are explicitly beneficial for ethe lectrochemical estimation of the actual performance of MFCs under real-time external loads
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    Polarization and power density trends of a soil-based microbial fuel cell treated with human urine
    (2020-03-14) Simeon, Meshack Imologie; Asoiro FU; Aliyu, M; Raji, OA; Freitag, Ruth
    Microbial fuel cells (MFCs) are bio-electrochemical devices that use microbial metabolic processes to convert organic substances into electricity with high efficiency. In this study, the performance of a soil-based MFC using urine as a substrate was assessed using polarization and power density curves. A single-chamber, membrane-less MFC with a carbon-felt air cathode and a carbon-felt anode fully buried in biologically active soil was constructed to examine the impact of urine treatment on the performance of the MFC. The peak power of the urine-treated MFC was 124.16 mW/m2 and was obtained 24 hours after the first urine addition; a control MFC showed a value of 65.40 mW/m2 in the same period. The treated MFC produced an average power of 70.75 mW/m2 up to 21 days after the initial urine addition; the control MFC gave an average value of 4.508 mW/m2 over the same period. The average internal resistances of the treated MFC and the control MFC obtained after the initial treatment were 269.94 and 1627.89 Ω, respectively. This study demonstrates the potential of human urine to reduce internal losses in soil MFCs and to provide stable power densities across various external resistors. These results are propitious for future advancements in soil MFCs for power generation, utilizing human urine (a readily available source of nutrients) as a substrate.