Fate and effect of quaternary ammonium compounds on a mixed methanogenic culture

• Published in: Water research (Oxford) Vol. 40; no. 19; pp. 3660 - 3668
• Main Authors: Tezel, Ulas, Pierson, John A., Pavlostathis, Spyros G.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.11.2006; Elsevier Science
• Subjects: Acidogenesis; Adsorption; Applied sciences; Bacteria, Anaerobic - drug effects; Bacteria, Anaerobic - metabolism; biodegradation; Biomass; Bioreactors; chemical concentration; Dextrins - chemistry; Dose-Response Relationship, Drug; Exact sciences and technology; Fatty Acids, Volatile - analysis; Fatty Acids, Volatile - metabolism; Freundlich isotherm equation; Inhibition; mesophilic bacteria; Methane - biosynthesis; Methane - metabolism; methane production; Methanogenesis; methanogenesis inhibition; methanogens; microbial activity; microbial growth; Other industrial wastes. Sewage sludge; Peptones - chemistry; Pollution; pollution control; Quaternary ammonium compounds; Quaternary Ammonium Compounds - chemistry; Quaternary Ammonium Compounds - pharmacology; simulation models; Surface Properties; Time Factors; volatile fatty acids; Wastes; Water treatment and pollution; Quaternary ammonium compounds; Inhibition; Acidogenesis; Methanogenesis; Methane; Ammonium; Quaternary; Adsorption isotherm; Volatile organic compound; Biomass; Adsorption; Batchwise; Mesophily; Volatile fatty acid; Reactor; Organic compounds
• ISSN: 0043-1354; 1879-2448
• DOI: 10.1016/j.watres.2006.06.019

The potential inhibitory effect of four quaternary ammonium compounds (QACs) and Vigilquat ®, a commercial sanitizer which is a mixture of the four QACs, was investigated at concentrations up to 100 mg/L using a mixed, mesophilic (35 °C) methanogenic culture. Dextrin and peptone were used as the carbon and energy sources. A batch assay conducted at a range of QAC concentrations showed that QACs were inhibitory to methanogens at and above 25 mg/L. Methanogenesis was more susceptible to QAC inhibition than acidogenesis. Adsorption of QACs on biomass was successfully simulated with the Freundlich isotherm equation. The inhibitory effect of Vigilquat ® on the mixed methanogenic culture was also investigated in a batch reactor fed with dextrin and peptone. Methanogens were inhibited when the total QAC concentration reached 30 mg/L and volatile fatty acids (VFAs) accumulated. However, methane production recovered in 57 days of incubation, and all VFAs were consumed, suggesting that a prolonged incubation period is necessary for the methanogens to overcome the transient inhibition at a relatively low QAC concentration. None of the QACs tested in this study was biodegraded under methanogenic conditions.