Isolation of crude-oil-degrading Sphingomonas paucimobilis from the Persian Gulf and Caspian Sea

Abstract

Oil spills are a major menace to the environment because they severely damage the surrounding ecosystems. Persian Gulf in this century, Situating in the middle east, having more than 65 percent of world’s oil and gas resources, having huge biodiversity and existing rich resources of pearls and shells have made this location unique and valuable. Oil and gas field wastewater or produced water is a significant waste stream in the oil and gas industries. In this study, the performance of sequencing batch reactor (SBR) and sequencing batch reactor  process treating produced wastewater were investigated and compared. The SBR was operated in different hydraulic residence time (HRT) of 8, 20 and 44 h. Operation results showed that for a HRT of 20 h, the combined process effluent chemical oxygen demand (COD, oil removal efficiencies were 90.9 and 91.5 %, respectively .In this study, sequencing batch reactor(SBR) was used to treat synthetic and real produced water crude-oil-degrading Sphingomonas paucimobilis bacteria was isolated from oil-contaminated sites in the Persian Gulf and the Caspian Sea. Based on a high growth rate on crude oil and on hydrocarbon degradation ability. The combination of a SBR inoculated with a consortium of isolated halophilic microorganisms and a membrane filtration is an efficient, reliable, and compact process for organic matter produced water treatment without prior dilution.