Kinetics of Indigenous Isolated Bacteria Bacillus mycoides Used for Ex-Situ Bioremediation of Petroleum Contaminated

Bioremediation of petroleum sludge was done by using land farming method in micro scale; the samples were taken from PT Pertamina Musi Banyuasin district of South Sumatra. This process applied Bacillus mycoides bacteria which isolated and selected from the contaminated soil. The research aim is to evaluate the performance of the Bacillus mycoides bacteria in degrading petroleum sludge pollutants. The initial TPH concentrations of soil contaminated sludge samples were set up at; 4.18, 6.60, 9.82, 10.87 and 13.42%, which were diluted from the main contaminated soil sample with a concentration of Total Petroleum Hydrocarbon (TPH) of contaminated soil was 71.16%. Every sample is inoculated by Bacillus mycoides bacteria as much as 10 % v/w and stirred homogeneously. The incubation time was 14 days, and then the samples were analyzed for the TPH content. The results were 3.68, 4.51, 5.91, 6.02 and 8.00% respectively. The rate of the biodegradation process was determined by using differential method. The results of data analyses show that the reaction order is first order. The rate of biodegradation constant was determined by using integral method. The initial concentration of the sample was 9.82 %, and then it had been inoculated by Bacillus mycoides bacteria during 14, 17, 22, 26 and 31 days. The TPH concentrations decreased 5.91, 4.59, 4.05, 3.72 and 3.29% respectively. The results of data analysis show that the biodegradation was a first reaction order with a biodegradation reaction constant of 0.0361 day-1. The chemical kinetics model of the bioremediation model is y =-0.0362.x + 2.2448