Treatment of Industrial Mineral Oil Wastewater -Optimisation of Coagulation Flotation process using Response Surface Methodology (RSM)

摘要

With a wide range of applications of petrochemical products, most of the production consumes a larger amount of water than water produced. Oil in water is the major pollutant in the wastewater generated from these petrochemical and oil refinery industries. However, improper treatment when discharged will cause severe environmental issues. Therefore, it is important to recover most of the mineral oil (MO) and to purify the water for reuse. This is a good option to conserve and prolong the supply of the available water and oil. In this study response surface methodology (RSM) based on Box-Behnken design (BBD) matrix was used to optimise the coagulation flotation process and evaluate the behaviour of the manipulated variables. Three most influential factors viz pH, coagulant dosage and flotation time were adopted for this study to yield maximum removal of soap oil and grease (SOG), turbidity and total suspended solids (TSS) as the responses. The experimental results were consistent with the RSM predicted models of over 80% removal of the contaminants. This has proved to be effective to evaluate multiple factors simultaneously to identify the main factor to control for effective treatment and improve effluent quality. In this study, the coagulant dosage was deduced to be most influential factor to control.