Biodegradation of Soils Contaminated with Naphthalene in Petroleum Hydrocarbons Using Bioslurry Reactors

Abstract

Soil contaminated with naphthalene by the activities of exploration, production and disposal of petroleum waste into the environment causes serious damage to ecosystems environment. This is the target of processing by the bacteria as a model for remediation of soil contaminated with naphthalene. Thus, the study was focused on naphthalene biodegradation in soil contaminated with polyaromatic hydrocarbons with measurement parameters: the bacterial growth and dissolved oxygen. The research was conducted in a slurry bioreactor with soil to water ratio of 20:80 (%wt) with the addition of a consortia of Bacillus cereus and Pseudomonas putida bacteria with a concentration of 10% (v/v) and 15% (v/v). The slurry bioreactor was aerated, stirred with stirring of 100 rpm and temperature range of 26°C – 35°C. Naphthalene residue in petroleum hydrocarbons were measured using GC-MS. The result of identification with naphthalene initial concentration of 115.646 ng/uL, after 49 days of incubation for bacterial consortium 10% (v/v) with a bacteria ratio 3:2; 1:1; 2:3; and control showed the reduction to 33.77 ng/uL; 0.77 ng/uL; 10.28 ng/uL and 23.88 ng/uL, respectively with biodegradation percentages of 70.80%; 99.33%; 91.11%; and 79.35%. As for the bacterial consortium 15% (v/v) with the same ratio and control, the naphthalene concentration was reduced to 0.31 ng/uL; 0.19 ng/uL; 5.12 ng/uL and 23.88 ng/uL, respectively and biodegradation percentages of 99.73%; 99.84%; 95.57%; and 79.35%. This finding shows that percentage of crude low degraded considering the concentration crude oil increased.