Enhanced biodesulfurization of bunker oil by ultrasound pre-treatment with native microbial seeds

This work investigated the effect of ultrasound on the biodesulfurization of bunker oil by the native microbial cells in oil/water biphasic system. The operational parameters for the desulfurization procedure such as ultrasonic irradiation time, ultrasonic wave amplitude, biocatalyst initial concentration and ratio of oil phases to aqueous phases were studied. An obviously positive effect was observed after introduction of ultrasound into the BDS system. The sulfur content of bunker oil did not decrease in absence of ultrasound pre-treatment. After ultrasonic pre-treatment, about 10-20% of sulfur was removed for the samples without any additive and was dependent on ultrasonic irradiation time, ultrasonic wave amplitude, biocatalyst initial concentration and ratio of oil phases to aqueous phases. During the desulfurization, even though an easily available carbon source, glycerol, was supplied, some low molecular weight hydrocarbons can be consumed by cells as carbon source, resulting in a loss in the fuel value or energy loss.