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Changes in residual concentration of PAHs in planted and bioaugmented crude oil polluted tropical soils

Ifechukwu Enyinnaya Adieze, Justina Chibuogwu Orji, Rose Nkechinyere Nwabueze, Geoffrey Okike C. Onyeze

Microbiology Department, Federal University of Technology, Owerri, Nigeria

Biochemistry Department, Federal University of Technology, Owerri, Nigeria

Key words: Bioaugmentation, Panicum maximum, PAHs, Phytoremediation.


Effects of bioaugmentation of vegetated crude oil polluted soils on the residual concentration of PAHs were examined in microcosms in a green house study. Weathered crude oil polluted soils (2% w/w) in 4 sets of pots were respectively planted and bioaugmented with hydrocarbon utilizing species (Micrococcus sp. RZI, Pseudomonas sp. RZIII, Bacillus sp. RZIII and Bacillus sp. GSIII). Polluted vegetated and polluted non-vegetated control soil samples were also set up. At intervals between setup and the tenth week of incubation, soil samples from three replicates of each treatment chosen randomly were analysed for soils’ residual PAHs concentrations. The results obtained showed that 10 weeks after planting (WAP) residual PAHs concentrations in polluted soils were 34.3 mg/kg; 31.6 mg/kg; 26.1 mg/kg and 25.9 mg/kg respectively for vegetated control soil, vegetated soil bioaugmented with Micrococcus sp.RZI, vegetated soil bioaugmented with Bacillus sp. RZIII and vegetated soil bioaugmented with Pseudomonas sp. RZIII. Compared to concentrations in polluted non-vegetated samples, there was 78.8%, 76.6%, 80.8% reductions in pyrene, benzo (b) fluoranthene, indeno (1,2,3-C-D) pyrene and 1,2,5,6-dibenzanthracene respectively in polluted vegetated samples bioaugmented with Pseudomonas sp. RZIII. These show that bioaugmentation of vegetated polluted soils with hydrocarbon utilizing species can enhance PAHs removal from weathered petroleum polluted soils. This can be used to improve on the gains of phytoremediation particularly with respect to carcinogenic PAHs.

Get the original articles in Source: Volume 6, Number 6, June 2015 – JBES

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