Study on application of salt-tolerant bacteria in high-salinity cycloamine wastewater from natural gas purification plant

Author of the article:PENG Jie1, XIAO Fang1, LI Li2, JIN Yan2

Author's Workplace：1. CPECC Southwest Company, Chengdu, Sichuan, 610041, China; 2. National Engineering Research Center for Integrated Utilization of Salt Lake Resources, East China University of Science and Technology, Shanghai, 200237, China

Key Words：Natural gas purification plant; APU wastewater; Salt-tolerant bacteria; Biochemical oxidation; Bacteria strain screening

Abstract：The amine purification unit wastewater produced in the desulfurization process of Cansolv process in natural gas purification plant has the characteristics of high salt content and high organic matter, so it cannot be directly treated by biological method or physical and chemical oxidation methods. In order to solve the problem of high-salinity cycloamine wastewater treatment, this study separated and screened highly efficient salt-tolerant bacteria from sewage samples to enhance the biochemical treatment, and adopted the APU wastewater treatment process combining chemical oxidation and biological methods, and optimized the operating conditions. The results showed that the biodegradability of APU wastewater had significantly improved after chemical oxidation treatment. The electro-dialysis water was chemically oxidized to be biochemical oxidation feedstock, and the COD (chemical oxygen demand) removal rate could be stabilized at 45%~50%, the effluent COD concentration could be stabilized within 100 mg/L, the total nitrogen concentration was below 30 mg/L, and the ammonia nitrogen was less than 1 mg/L. The effluent water meets the water quality standards for discharging into municipal sewage piping network and provides reference for the application of salt-tolerant bacteria in the APU wastewater treatment in natural gas purification plant.