This study was undertaken to evaluate a novel aerobic wastewater treatment model for the remediation of refinery effluents and to assess the removal efficiency of Bulkholderia cepacia strain AJI and Corynebacterium kutscheri strain AJ2 to clean oil waste from petrochemical company. Wastewater quality parameters including pH, BOD5, COD, TDS, OIL & GREASE, PHENOL concentration, TPH and THC were monitored at 5, 10 and 15 days of treatment and the removal efficiencies were calculated. Results indicated that the raw oily wastewater effluents used during this study had extremely high levels of all the tested parameters. The mean values  of  all physicochemical parameters  of the wastewater from primary tank at different treatment period were statistically different (P˂0.001) After 15 days of biological treatment, BOD5 ,COD, TDS, Phenol, TPH, Oil & grease level of the refinery wastewater were reduced by 95.60 %, 98.40 % , 66.34 % , 100 %, 97.60 %  and 96.20 % respectively. The detection of the catabolic genes in the bacterial isolates recovered from primary tank using polymerase chain reaction revealed that both Bulkholderia cepacia strain AJ1 and Corynebacterium kutsheri strain AJ2 carried alk B and C23O but C12O was not detected in both isolates. Naphthalene dioxygenase was detected in Bulkholderia cepacia strain AJ1 but not found in Corynebacterium kutscheri strain AJ2. After treatment the waste water was filtered in the secondary tank. The results of physicochemical parameters in the outlet vessel essentially confirmed that the mixed culture in the two column model successfully carry out bioremediation of refinery wastewater. Therefore, aerobic treatment model for the bioremediation of refinery Petroleum refineries generate great amounts of wastewaters that may become seriously dangerous, leading to the accumulation of toxic products in the receiving water bodies with potentially serious long term effects to aquatic biota. Due to extreme toxicity of contaminants in refinery wastewater, there is a need to develop an economical technique to remove the pollutants from the wastewater is highly recommended owing its environmental friendliness.

The present research studies the performance of Converter Sludge (CL)as a nano-activator of persulfate (PS) in Permeable Reactive Barrier (PRB) as an in-situ technology for leachate treatment.In batch experiments, the acidic conditions (pH = 3) have been the most suitable for removal operations, where COD and NH3 removal efficiencies are 69.15% and 60.96%, respectively. The Box–Behnken design (BBD) has been employed to optimize three parameters, namely PS/ COD ratio, CS dose, and pore volume (PV), using COD and NH3 of leachate landfill as the target pollutant. The BBD is considered a satisfactory model to optimize the process. Under optimal conditions (PS/COD ratio: 3.47, CS dose: 3.09 g L-1,and PV: 4.27), the measured values of the COD and NH3 removal efficiencies have been 74.2 and 66.8, respectively, all within the 95%-prediction intervals, which indicate the model’s success in predicting removal values. The biodegradability (BOD5/COD) of the real leachate has been enhanced from 0.25 to 0.77, with the toxicity of real leachate getting decreased by more than 90%.