Enhanced biodegradation of oily wastewater through nuclear irradiation mutation and statistical experimental methodology

Journal of Water Reuse and Desalination

Li, Shuang¹  He, Yong-Ming²  Li, Zhong-Quan³  Duan, Xin-Guo³ 

[1]College of Earth Sciences, Chengdu University of Technology, Chengdu 610059, Sichuan, China

[2]College of Energy Resources, Chengdu University of Technology, Chengdu 610059, Sichuan, China

[3]State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Chengdu University of Technology, Chengdu 610059, Sichuan, China and Key Laboratory of Tectonic Controls on Mineralization and Hydrocarbon Accumulation, Ministry of Land and Resources, Chengdu University of Technology, Chengdu 610059, Sichuan, China

关键词: biodegradation;    enzyme activity;    mutation;    optimization;    response surface methodology;   

DOI  :  10.2166/wrd.2015.106

学科分类：工程和技术（综合）

来源: IWA Publishing

【 摘 要 】

This study presents the improved biodegradation of crude oil in aqueous phase using mutant Dietzia sp. obtained by random mutagenesis of wild Dietzia sp. using 60Co-γ irradiation. The mutants obtained were screened based on their degradation performance and the best mutant was selected for oil degradation optimization research. A four factor central composite design coupled with response surface methodology was applied to evaluate and optimize the important variables. A genetically stable mutant, designated as M22, was isolated and demonstrated significantly higher degradation efficiency (52.5%) of total petroleum hydrocarbons (TPHs) than the parental strain (28.2%) in liquid media after 14 days of incubation. Increased production of enzyme responsible for the degradation was achieved with the mutant species. Optimum conditions were determined to be pH 7.6, 0.20 g/L K2HPO4, 0.57 g/L NH4NO3, and 0.62 g/L yeast extract. Approximately 68.5% of TPH was experimentally degraded after 14 h of incubation under the optimum conditions, which agreed well with the model prediction. Gas chromatography-mass spectrum analysis showed that the mutant M22 could degrade a wide range of crude oil fractions, while optimization of culture conditions could be effective for increasing its strain's degrading ability.

【 授权许可】

CC BY-NC-ND