Screening and characterization of high performance synthetic-based drilling fluids degrading bacteria

Abstract

Abstract In this paper, eight degrading bacteria using waste high performance synthetic-based fluids (WHPSF) as sole carbon source were isolated. Genetic analysis showed that these strains belonged to 8 species, and distributed in 3 genera. Of them, genus Bacillus was the predominated one with 6 strains. Based on the COD removal rate, 3 effective strains, i.e. SQ17, SQ8-1 and SQ6-1, were screened; and SQ6-1 had the highest COD degradation rate (40.26%). Growth characteristic analysis indicated that SQ8-1 and SQ6-1 could grow at initial pH value from 4.0 to 10.0, and grow at 10 °C to 40 °C. Moreover, these bacterial strains had strong ability to degrade WHPSF, and both the bacteria amount and COD removal rate increased along with treating time. The results suggested that these bacteria could degrade WHPSF properly, and had good application potential.