Bioremediation of Pyrene Contaminated Soil using Isolated Mixed Culture
Authors: Ibn Abubakar BSU, Abdullah N, Idris A, Zakaria MP, Shokur MY
In this research, bioremediation of pyrene (Pyr) contaminated soil using isolated mixed culture containing Bacillus cereus and Entrobacter aerogenes was investigated. A factorial design (FD) was employed to investigate and optimize the bioremediation of Pyr-spiked soils with various sets of operating conditions in soil-slurry batch reactors. From the results, biomass growth was dependent on Pyr concentration and slurry initial pH, but not soil/water ratio. Designed points of soil/water (13%), Pyr/soil (1000 mg/kg) with a pH of 6.5 gave about 90% removal of Pyr within the first six days of incubation. The chosen soil/water ratio might provide adequate space for mixing and microbial mobility within the soil-slurry reactors. A comparison of soil properties on biodegradation of Pyr in three different Pyr-spiked soils showed that soil A (Munchong series) had the highest rate of percentage degradation (97.6%) and soil B (Silty clay) had the lowest rate of percentage degradation (74.24%). Average percentage degradation for all the three soils A, B, and C (Clay loam) were 91.42%, 90.07% and 92.12% respectively. On the overall, there were no marked differences in percentage degradation of Pyr among all the soils examined. Therefore, careful determination of factors that control biomass growth, contaminant concentration and soil characteristics may provide efficient solutions to remediation projects.
Affiliations: Department of Civil and Water Resources Engineering, Faculty of Engineering, University of Maiduguri, PMB 1069, Maiduguri, Nigeria.
Keywords: Pyrene, Soil-water Ratio, Percentage Degradation, Pyrene-soil Ratio, Biomass Growth
Published date: 2018/12/30