Biodegradation Kinetics and Mechanism of a Typical Coal Gasification Pollutant: Quinoline

Peng Xu, Hong-Jun Han, Sheng-Yong Jia, Bao-Lin Hou, Hai-Feng Zhuang, Qian Zhao

(State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150090, China)



Abstract:

A strain Pseudomonas sp. PP1 was isolated from activated sludge and characterized by morphological observation, biochemical and physiological identification as well as 16S rRNA gene sequence analysis. It was a gram-negative, non-motile, rod-shaped with colonies which were white, opaque, small and wrinkled on solid quinoline-MSM. The strain was negative for catalase, gelatin liquefaction, M. R and V. P tests and was unable to reduce/restore nitrate. The 1406 bp 16S rRNA gene fragment of PP1 was more than 99£¥ identical to the Pseudomonas sp. Biodegradation of quinoline as single substrate was conducted in batch experiments at different temperatures (15-40 ¡æ) and pH values (5-10). The results indicate that the optimum conditions for the degradation of quinoline by PP1 were 30 ¡æ and pH 7. Pseudomonas sp. PP1 was able to degrade 97.1£¥, 95.4£¥, 94.8£¥, 63.6£¥ and 40.4£¥ quinoline when initial concentrations of quinoline were 0,0, 0,0, and 400 mg/L, respectively, and lag phases were prolonged from 2 h to 10 h. The maximum degradation rate (q) was obtained at an initial quinoline concentration (S₀) of about 100 mg/L with q of 0.082. The experimentally obtained q values at various initial S₀ were fitted by Haldane model, Yano model, Aiba model, Edward model and Webb model, and the results demonstrated that Haldane model gives the best fit for strain PP1 with coefficient of determination, R²=0.9124 and SD_avg=0.0113208. Five metabolic intermediates were identified by high performance liquid chromatograph (HPLC) and GC/MS. Finally, a possible pathway containing 5,6-dihydroxy-2-oxo-1,2-dihydroquinoline as an intermediate was proposed for the first time.

Key words:  ª§pseudomonasª§ sp.  quinoline  biodegradation kinetics  pathway

DOI£º10.11916/j.issn.1005-9113.2014.06.019

Clc Number:X506

Fund: