Influence of quaternary ammonium compounds on the microbial reductive dechlorination of pentachloroaniline.
The inhibitory effect of two widely used quaternary ammonium compounds (QACs)--alkyl benzyl dimethyl (AB) and hexadecyl trimethyl (HD) ammonium chloride--on fermentation, methanogenesis and pentachloroaniline (PCA) dechlorination was assessed using a mixed, methanogenic, PCA-dechlorinating culture amended with AB or HD at a concentration range from 5 to 70 μM. PCA dechlorination was inhibited at 5 μM AB and was completely inhibited at 25 or 5 μM by AB or HD, respectively. However, the PCA dechlorination pathway was the same in both the QACs-free and QACs-amended culture series. Fermentation (acidogenesis) and methanogenesis were inhibited by both AB and HD at and above 25 μM but to a lesser degree than PCA dechlorination. Overall, HD resulted in a more severe inhibition of the mixed culture than AB. Adsorption of both QACs to the mixed culture biomass followed the Freundlich isotherm model. The adsorption affinity of HD for the mixed culture biomass was significantly higher than that of AB, which may be related to the observed higher inhibitory effects of HD compared to AB. Both AB and HD were not degraded in the mixed, dechlorinating culture used in this study.
School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332-0512, USA; School of Environmental Science and Engineering, Shandong University, 250100 Jinan, China.
Jinglan
J
Hong
Ulas
U
Tezel
Didem
D
Okutman Tas
Spyros G
SG
Pavlostathis
D000085:Acetates / Q000378:metabolism; D000327:Adsorption; D000814:Aniline Compounds / Q000737:chemistry / Q000378:metabolism*; D001419:Bacteria / Q000187:drug effects / Q000378:metabolism*; D001673:Biodegradation, Environmental / Q000187:drug effects; D057919:Biological Oxygen Demand Analysis; D018533:Biomass; D001711:Biotransformation / Q000187:drug effects; D002245:Carbon Dioxide / Q000378:metabolism; D005285:Fermentation; D054879:Halogenation / Q000187:drug effects*; D008697:Methane / Q000096:biosynthesis; D010084:Oxidation-Reduction / Q000187:drug effects; D011422:Propionates / Q000378:metabolism; D000644:Quaternary Ammonium Compounds / Q000737:chemistry / Q000494:pharmacology*; D013696:Temperature; D013997:Time Factors
D000085:Acetates; D000814:Aniline Compounds; D011422:Propionates; D000644:Quaternary Ammonium Compounds; D002245:Carbon Dioxide; D008697:Methane; C027673:2,3,4,5,6-pentachloroaniline
Chlorinated anilines; Dechlorination; Inhibition; Methanogenesis; Quaternary ammonium compounds