Application of the central composite design to optimization of petroleum hydrocarbons removal from oilfield water using advanced oxidation process

In the last few years, RSM method has been used widely to analyze, optimize and evaluate the interaction of independent factors for chemical, biochemical, and environmental processes. This study examined and evaluated the applicability of this method to manage Oilfield Produced Water to prevent marine environment due to the presence of hard degradable compounds by ozonation process. In this study simulated oil-water sample and a homogenizer reactor was used. The main reactor used in this study was impeinger equipped with sintered glass filter through which the treated oil-water was entered to reactor in the form of discontinuous flow. After ozonation and at the end of the reaction time (60 min), the concentration of oil hydrocarbons was determined by a gas chromatography device equipped with a flame ionization detector. The performance of the central composite design (CCD) approach was evaluated by the F-Value, P-Value, R², lack of fit test and Adequate Precision parameters to determine the influence of effective factors, including ozonation time, pH, ozone dose, and TPH concentration on the TPH removal efficiency. The mean TPH efficiency obtained from the design of the 30-step experiment resulting from surface-response method was 49.903%, with a standard deviation of 12.47. This study showed the high power of model adopted from the central composite design to predict the hydrocarbons removal from oilfield water using advanced oxidation process, and it was proved that this model can be used alone to determine the design space nature.