A study on the impact of baffle submergence and air flow rate on the separation efficiency of oil and grease from refinery wastewater

The impact of airflow rate, baffle submergence, and baffle position on the efficiency of oil and grease separation in aeration-based wastewater treatment systems was examined in this study. The objective was to optimize the oil separation process by analyzing how these factors influenced separation efficiency. Experiments were carried out at varying airflow rates (0.1, 0.2, 0.4, 0.5, and 0.8 L/s), using a pore diameter of 1.5 mm and baffle submergence of 1, 5, and 10 cm. The presence of both transverse and longitudinal baffles inside the basin was tested at a water depth of 45 cm. The highest separation efficiency of 45.29% was achieved at an airflow rate of 0.4 L/s when a longitudinal baffle was submerged at 5 cm, along with the presence of both transverse baffles. A decrease in efficiency was observed at higher airflow rates due to excessive turbulence and oil emulsification. Additionally, the placement of transverse baffles at both positions was found to enhance separation efficiency to 36.3%, compared to 27.3% and 29.5% when a single baffle was placed individually at the first and second positions, respectively. All tests were performed using a gravimetric method. These findings emphasized the importance of optimizing airflow rates and baffle position for effective oil and grease separation, offering valuable insights into the design and operation of aeration systems in wastewater treatment.