Modeling and optimization of oil refinery wastewater chemicaloxygen demand removal in dissolved air flotation system byresponse surface methodology

In this present study the dissolved air flotation (DAF) system was investigated for thetreatment of Kermanshah Oil Refinery wastewater. The effect of three parameterson flotation efficiency including flow rate (outflow from the flotation tank),saturation pressure and coagulant dosage on chemical oxygen demand (COD)removal was examined experimentally. All the experiments were done under acertain time (in this case 3 min). After final testing maximum COD removal efficiencywas obtained 67.86%. In the next step of study, response surface method (RSM) wasapplied to model oil refinery wastewater COD removal as a function of flow rate,saturation pressure and coagulant dosage. Coefficient of determination, R2, showedthat the RSM model can explain the variation with the accuracy of 0.996, indicatingthere was strong correlation. Moreover, process optimization was performed topredict the best operating conditions using RSM method, which resulted in themaximum COD removal of the oil refinery wastewater. The maximum COD removalof oil refinery wastewater was estimated by RSM to be 67.87% under the operationalconditions of flow rate (3.76 – 3.86 L/min), saturation pressure (4.99 - 5bar) andcoagulant dosage (24.16 – 24.79 mg/L).

کلیدواژه ها:

Dissolved air flotation ، Chemical oxygen demand ، Response surface methodology