Research Article
Abdullah M Elmahdi, Hamidi Abd
Abstract
The objective of this research was to evaluate the effectiveness of the use of solid waste date (SWD) as a lowcost natural agro-industrial materials, in improving crude oil biodegradation in contaminated sea water. Two types of Libyan crude oil (heavy crude oil (HCO) and light crude oil (LCO)) were used in this study. Batch reactors with sea water were used as bioreactors. A central composite design (CCD) with response surface methodology (RSM) was applied to evaluate the relationship between operating variables, including HCO and LCO initial concentrations, SWD dosage, and incubation time, to determine the optimum operating conditions. Quadratic models of both CO biodegradation (%) were significant with very low probability values (<0.0001). The results indicated that under optimum operational conditions (i.e, SWD dosage of 0.21g/L in 11dayes for HCO and 0.20 g/L in 14 days for LCO), the best biodegradation efficiency of HCO and LCO were 79.49% and 94.15%, respectively. The predicted results of 82.10% and 95.45% fitted well with experimental results (HCO and LCO removal rates of 97.05% and 99.10%, respectively). Based on removal rates of 5.5% and 14.7% for both HCO and LCO without SWD, respectively, in 28 days, the obtained results revealed that SWD was very efficient in improving the biodegradation of high-concentration crude oils that contaminate sea water.