CE=8.I.dt/(F.V.delCOD)
Why Coulombic efficiency and COD removal is inversely related. If COD removal is high, the Coulombic efficiency is low and vice versa. Please explain the principle behind this
In microbial fuel cells (MFCs), the Coulombic efficiency and Chemical Oxygen Demand (COD) removal are two important performance indicators that reflect the efficiency of the system in converting organic matter into electricity.
CE = (Total electrons transferred as current) / (Total electrons theoretically available from COD)
A Coulombic efficiency of 100% indicates that all the electrons released during microbial metabolism are successfully harvested as electricity in the MFC. However, in practical systems, the Coulombic efficiency is usually less than 100% due to factors such as electron losses to side reactions (e.g., microbial biomass formation) and inefficiencies in electron transfer.
COD Removal (%) = [(Initial COD - Final COD) / Initial COD] x 100
A higher COD removal indicates a more effective treatment of organic pollutants in the wastewater.
Relationship between Coulombic Efficiency and COD Removal: The relationship between Coulombic efficiency and COD removal in MFCs can vary depending on the operating conditions and the nature of the organic matter present in the wastewater.
In some cases, a higher COD removal may be associated with a higher Coulombic efficiency. This is because a more efficient microbial degradation of organic matter can lead to increased electron generation, which can then be harvested as electricity, resulting in a higher Coulombic efficiency.
However, there may be instances where a trade-off exists between COD removal and Coulombic efficiency. For example, certain operating conditions or microbial communities might favor the complete degradation of organic matter to carbon dioxide, resulting in a high COD removal but lower Coulombic efficiency as fewer electrons are available for electricity generation.
In summary, while there can be a positive correlation between Coulombic efficiency and COD removal in MFCs, it is not a straightforward relationship and can be influenced by various factors. The optimization of MFC performance involves finding a balance between maximizing organic matter removal and electricity generation.
Thank you very much for the detailed explanation Samsul Islam . In my case, i am able to attain 85% COD removal, if i substitute the values in the formula, since the denominator (COD removal) is higher, that leads to lower value of Coulombic efficiency. If i substitute a lower value for COD removal, Coulombic efficiency increases. Is there any other formula foe coulombic efficiency calculation
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