Initial Creavage of Propylene Glycol with Mixed Culture under Anaerobic Conditions

• Published in: 한국수처리학회지, 29(1) pp. 3 - 8
• Main Author: 석종혁
• Format: Journal Article
• Language: English
• Published: 한국수처리학회 28.02.2021
• Subjects: 토목공학
• ISSN: 1225-7192; 2289-0076
• DOI: 10.17640/KSWST.2021.29.1.3

This study was conducted to identify intermediate products and a possible pathway of propylene glycol degradation under anaerobic conditions. In a 60-day continuous run of two chemostat in series, suspended growth was inoculated with a detached biofilm from the anaerobic fluidized bed bioreactor(AFBR) carriers. The influent was made up of 9.0g COD/L of propylene glycol with an essential nutrient supplement for anaerobes. The fermentative bacteria were dominant in the reactor. Propionaldehyde, propionate, propanol and acetate were detected and identified in the anaerobic propylene glycol degradation. Propionate and propanol were produced at equal concentrations in the intermediate products. No significant growth of microorganisms was observed in the reactor under the imposed experimental conditions. A considerable amount hydrogen was observed at about 1.08~1.10×10-3atm, indicating that hydrogen plays a key role in the anaerobic propylene glycol degradation. This suggests a possible pathway, where propionaldehyde is an intermediate via a dehydration reaction in the initial diol cleavage. This result leads to a hypothesis of a possible pathway that has propionaldehyde as a transient intermediate product in the very initial degradation stages of propylene glycol. Propionaldehyde would then be disproportionated into an equal molar amount of propionate and n-propanol, which would be further converted to acetate and hydrogen. Propionate would be subsequently degraded to acetate, carbon dioxide and hydrogen. Lastly, methane would be produced both from acetate by acetoclastic methanogens and from hydrogen and carbon dioxide by hydrogenotrophic methanogens. KCI Citation Count: 0