Effect of surfactants on the bioremediation of oily sludge from gasoil storage facilities

This research documents the effects of Tween 80 as a nonionic surfactant and sodium dodecyl sulfate (SDS) as an anionic surfactant on the bioremediation of oily sludge. An oily sludge batch with TPH (total petroleum hydrocarbon) content of 6.8% was obtained from a gasoil storage facility. Both surfactants were examined at dosage levels of 0, and 2 mg/kg, each at three moisture content of 15, 25, and 40%. A group of petroleum degrading microorganisms were inoculated to the oily sludge samples. The moisture content of the samples was restored to their initial values in two-day intervals. After 45 days the TPH content of the samples were quantified. The results confirmed the effectiveness of Tween 80 with more than 67% removal of TPH at Tween 80 concentration of 2 mg/kg, and the moisture content of 40%. SDS showed no statistically significant effect on bioremediation. In a separate experiment, the TPH removal was monitored in the presence of Tween 80 as a function time. The bioremediation was accelerated during the second week and continued slowly after the fifth week. The effect of sucrose as an inducer on the bioremediation of oily sludge was also examined in this research work. Sucrose was added to the oily sludge at six dosage levels of 0, 5, 15, 30, 50, and 100 mg/kg. The results showed significant acceleration of microbial activity due to this treatment, with more than 60% TPH removal within a month at the sucrose concentration of 100 mg/kg.

Automated summary

This research found that Tween 80 showed a high efficiency in removing TPH, while SDS had no statistically significant impact. Additionally, the addition of sucrose significantly accelerated microbial activity and promoted the bioremediation of oily sludge, indicating the potential role of sucrose as an inducer in bioremediation.