Efficient and eco-friendly mixed bacterial consortium for petroleum wastewater treatment: Effect of the bio-augmentation and biosurfactant addition on hydrocarbon biodegradation

Abstract

In the present investigation, we aimed to study biological petroleum wastewater treatment. A bioprocess based on the use of a mixed bacterial consortium along with the addition of Biosurfactant (BioS) and bioaugmentation with BioS producing strains were evaluated. The consortium was the combination of two bacterial strains with the capacity to metabolize hydrocarbons, Baci and B201. Two other strains BH1 and BSS2 selected for their ability to degrade hydrocarbons as well as to produce BioS were also exploited. The effect of ex-situ and in-situ produced BioS on hydrocarbon biodegradation were compared. Obtained results demonstrated a moderate capacity to remove crude oil from contaminated water of about 47% for the consortium. The best improvement of hydrocarbon biodegradation of about 84% was obtained when adding BH1 derived BioS solely. However, ex-situ produced BioS exhibited better results. Regarding the wastewater characteristics, we note a decrease of the COD/BOD5 Ratio to reach 2.64. Thus, the wastewater became easily biodegradable. The described bioprocess is of great interest for the bioremediation of petroleum effluents. BioS addition as well as bioaugmentation enhanced crude oil removal.