LAUSR

One of the major environmental challenges of the oil industry is the permeation of petroleum and related products that cause intense soil pollution. Hydrocarbon oil polluted soils cannot be used for agricultural target because of hydrocarbon toxiscity. Bioremediation is a biotechnological technique which permits the treatment of oil polluted soil. In this work, design of experimental (DOE) method using Taguchi orthogonal array (OA) was performed to assess the influence of five factors (i.e., different levels of molasses concentration, whey concentration, urea concentration, use of indigenous microbial consortium as inoculum and Tween 80 as surfactant) on the removal efficiency of total petroleum hydrocarbon (TPH) from Iranian crude oil contaminated soils. The percent contribution of each factor was also calculated. The results showed that use of indigenous microbial and whey concentration made the highest (25.3%) and the lowest (13.7%) contribution, respectively. The total hydrocarbon content was reduced to 72.63% of its initial value at the optimal conditions at the end of the experiments. The study demonstrates that Taguchi method is appropriate to optimize the experiments for the efficiency of TPH removal (R2 = 0.974).