Effect of Polyvinyl Alcohol Gel Coated with Ferrihydrite on Propionic Acid Removal in Anaerobic Wastewater Treatment
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Abstract
Propionic acid is a crucial factor that influences the efficiency of anaerobic wastewater treatment, because its accumulation in the process decreases the pH levels. Therefore, this study focused on an approach that can alleviate this inhibitory effect from propionic acid. Polyvinyl alcohol (PVA) have been used for encapsulating active microorganisms in cell immobilization technology. Using PVA gel coated with Fh (FhPVA) as a biocarrier in the system, propionic acid can be removed to enhance capability of microbes for converting volatile fatty acid (VFA) into methane gas and decrease an inhibitory effect from VFA accumulation in the system. The specific surface areas (SSA) of PVA and FhPVA were estimated employing the methylene blue dye adsorption with spectrophotometric analysis. The adsorption affinity of each type of the media were computed using SSA and the residual propionic acid concentration obtained from the experiment. The SSA were found to be 1.41 m2 g-1, 0.40 m2 g-1 for PVA and FhPVA, respectively. From the result, it can be assumed that the impregnation process results in pore blockages, so the surface area of FhPVA is apparently lower than PVA. In addition, the adsorption affinity of FhPVA towards propionic acid is much higher than PVA, which were 19.39 mg L-1m-2 and 5.29 mg L-1m-2, respectively. Lastly, this study is only the first step that illustrates the probability of using Fh for improving the efficiency of the anaerobic system, but further study is needed for discovering a better approach for coating Fh on the media.
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References
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