Petroleum Research (Sep 2021)
Bioremediation and detoxification of real refinery oily sludge using mixed bacterial cells
Abstract
Anaerobic biotreatment of real field petroleum refinery oily sludge (PROS) was investigated under using four different organic loads (OLs) in the order of OL4 > OL3 > OL2 > OL1, in bench-scale bioreactors. The bioremediation of raw PROS was carried out using mixed culture biocatalyst without chemicals addition or any type of pretreatment. The results revealed a potential performance of the used biocatalyst dominated by Pseudomonas aeruginosa (class: Gammaproteo) and Staphylococcus spp. (class: Bacilli) achieving significant removal of chemical oxygen demand (COD) and total petroleum hydrocarbons (TPH). The highest organic removal rate was recorded in OL4 followed by OL3, OL2, OL1, respectively indicating a positive relationship between the percentage removal of organics and their content. Maximum removal efficiencies of 96.7% and 90% were observed for COD and TPH, respectively in OL4 within 14 days only. Analysis of polycyclic aromatic hydrocarbons (PAHs) demonstrated that acenaphthylene and phenanthrene exhibited the maximum removal efficiency (almost complete) among the 8-priority PAHs tested in this study. However, the overall degradation of PAHs in the oily sludge was 83.3%.
