Effectiveness of Single and Microbial Consortium of Locally Isolated Beneficial Microorganisms (LIBeM) in Bioaugmentation of Oil Sludge Contaminated Soil at Different Concentration Levels: A Laboratory Scale

Abstract

An aerated static pile ASP-bioreactor system made up of acrylic material dimension (60 cm × 40 cm × 20 cm) was developed to examine the potential of single and microbial consortium of LIBeM to remediate oil sludge contaminated soil at different concentration levels. Three different strains of LIBeM namely P. aeruginosa-BAS-Cr1, S. paucimobilis-ReTOS-Cr1 and S. maltophilia-RAS-Cr1 were used in this study was obtained from Environmental Microbiology Laboratory, Universiti Malaysia Sabah. Five sets of experiment filled with 10 kg of soils contaminated with 5% and 10% of oil sludge were carried out as Treatment 1 (contaminated soil+P. aeruginosa-BAS-Cr1), Treatment 2 (contaminated soil+S. paucimobilis-ReTOS-Cr1), Treatment 3 (contaminated soil+S. maltophilia-RASCr1), Treatment 4 (contaminated soil+Microbial Consortium; P. aeruginosa-BAS-Cr1+S. paucimobilis-ReTOSCr1+ S. maltophilia-RAS-Cr1) and Treatment 5 (contaminated soil+indigenous bacteria in soil; NA). Their ability to degrade hydrocarbon in the soil was investigated during 60 days incubation periods. Physical and chemical analyses were carried out from each of the treatment and control plot on a weekly basis to check for pH, moisture content, temperatures and Total Petroleum Hydrocarbon (TPH). The results showed that single strain P. aeruginosa- BAS-Cr1 has the highest oil degrading capacity compared to microbial consortium with 80% and 85.2% at both concentration studied. The percentage of TPH removal by P. aeruginosa-BAS-Cr1 is 3-fold higher than NA, thus confirmed that the addition of oil selective degrading bacteria was much better than the control plot. High degradation of long chain alkanes were observed between the control and treatment plot suggested that bioaugmentation using single and microbial consortium had decrease the level of oil sludge in contaminated soil.