Effect of didecyl dimethyl ammonium chloride on nitrate reduction in a mixed methanogenic culture.
The effect of the quaternary ammonium compound, didecyl dimethyl ammonium chloride (DDAC), on nitrate reduction was investigated at concentrations up to 100 mg/L in a batch assay using a mixed, mesophilic (35 degrees C) methanogenic culture. Glucose was used as the carbon and energy source and the initial nitrate concentration was 70 mg N/L. Dissimilatory nitrate reduction to ammonia (DNRA) and to dinitrogen (denitrification) were observed at DDAC concentrations up to 25 mg/L. At and above 50 mg DDAC/L, DNRA was inhibited and denitrification was incomplete resulting in accumulation of nitrous oxide. At DDAC concentrations above 10 mg/L, production of nitrous oxide, even transiently, resulted in complete, long-term inhibition of methanogenesis and accumulation of volatile fatty acids. Fermentation was inhibited at and above 75 mg DDAC/L. DDAC suppressed microbial growth and caused cell lysis at a concentration 50 mg/L or higher. Most of the added DDAC was adsorbed on the biomass. Over 96% of the added DDAC was recovered from all cultures at the end of the 100-days incubation period, indicating that DDAC did not degrade in the mixed methanogenic culture under the conditions of this study.
Tezel
U
U
School of Civil and Environmental Engineering, Georgia Institute of Technology, 311 Ferst Drive, Atlanta, GA 30332-0512, USA.
Pierson
J A
JA
Pavlostathis
S G
SG
D002244:Carbon / Q000378:metabolism; D005232:Fatty Acids, Volatile / Q000378:metabolism; D005285:Fermentation / Q000187:drug effects; D005947:Glucose / Q000378:metabolism; D008697:Methane / Q000378:metabolism; D009566:Nitrates / Q000378:metabolism*; D009609:Nitrous Oxide / Q000378:metabolism; D010084:Oxidation-Reduction; D000644:Quaternary Ammonium Compounds / Q000494:pharmacology*
D005232:Fatty Acids, Volatile; D009566:Nitrates; D000644:Quaternary Ammonium Compounds; D002244:Carbon; D005947:Glucose; D009609:Nitrous Oxide; D008697:Methane; C027118:didecyldimethylammonium