Anaerobic biotransformation and potential impact of quinoline in an anaerobic methanogenic reactor treating synthetic coal gasification wastewater and response of microbial community

• Published in: Journal of hazardous materials Vol. 384; p. 121404
• Main Authors: Wu, Benteng, Wang, Jing, Hu, Zhenhu, Yuan, Shoujun, Wang, Wei
• Format: Journal Article
• Language: English
• Published: Netherlands Elsevier B.V 15.02.2020
• Subjects: Anaerobic digestion; Anaerobiosis; Bacteria - genetics; Bacteria - metabolism; Bioreactors; Coal; Coal gasification wastewater; Industrial Waste; Methane - metabolism; Microbial community; Microbiota; Performance robustness; Phenols - metabolism; Quinoline; Quinolines - metabolism; RNA, Ribosomal, 16S - genetics; Waste Water; Water Pollutants, Chemical; Quinoline; Performance robustness; Coal gasification wastewater; Anaerobic digestion; Microbial community
• ISSN: 0304-3894; 1873-3336
• DOI: 10.1016/j.jhazmat.2019.121404

[Display omitted] •The UASB reactor operated stably when the influent quinoline was within 600 mg L−1.•Phenol degraders showed a higher tolerance to quinoline than 2(1 H)-quinolinone.•Conversion of 2(1 H)-quinolinone was the rate-limiting step of quinoline degradation.•Genera Ornatilinea and Methanothrix played a critical role in quinoline degradation. Phenolic and quinoline compounds are the most primary organic pollutants in coal gasification wastewater (CGW), but the biotransformation of quinoline compounds under methanogenic condition and their potential impacts on treatment performance of CGW are still unclear. Anaerobic biotransformation pathways of quinoline in an upflow anaerobic sludge blanket reactor treating synthetic CGW and response of microbial community were firstly investigated. The result indicated that the degradation of 2(1 H)-quinolinone was the rate-limiting step for the complete conversion of quinoline under methanogenic condition. The reactor performed stably at total phenols concentration of 1000 mg L−1 with a gradual increase of quinoline concentration from 100 to 600 mg L−1. However, the reactor performance was rapidly deteriorated from 98% of COD removal to about 80% at quinoline concentration of 1200 mg L−1 resulting from the accumulation of 2(1 H)-quinolinone. Correspondingly, phenol utilization rate of sludge was significantly reduced by 61% while quinoline utilization rate of sludge was increased by 132%. As phenol degraders, Syntrophorhabdus gradually predominated along with the increase of quinoline concentration, but Syntrophus declined inversely. Compared with syntrophs, acetotrophic methanogens could quickly adapt to quinoline toxicity and tolerate higher quinoline stress. Therefore, anaerobic digestion is an effective method for eliminating quinoline and phenol in CGW.