The sewage treatment equipment mainly includes the following five aspects: the regulating tank balances and regulates the changes in the water quality of oily sewage and salt-containing sewage series to ensure that the subsequent treatment equipment stops as scheduled. The total volume of the homogenization conditioning equipment is 9,000 cubic meters, and the total retention time is 36 hours. The floating oil collection equipment is linked to reduce the load on the oil separation and air flotation equipment. The oil-water separator is characterized by its high water output effect and relatively small ground floor area. The two-stage air flotation series process is applied to enhance the removal effect of petroleum and ensure that the oil content in the biochemical influent meets the standards. The primary and secondary air flotation respectively adopt the vortex air flotation technology and local reflux pressurized dissolved air flotation to reduce the COD value and alleviate the load on the biochemical tank. In terms of filtration technology, the ozone catalysis + biological aerated filter process is adopted to enhance the biodegradability of the wastewater, further achieving the removal of organic substances such as COD and ensuring that the water quality meets the standards.

This part mainly uses its own volume to temporarily store the local sewage that exceeds the treatment capacity of the subsequent process, or uses the remaining volume in the tank to dilute the high-concentration sewage, so as to adjust the water quality and quantity of the subsequent treatment process, ensure the stability of the operation and have the function of oil removal at the same time. After the incoming water enters the oil-water separator, it is evenly distributed to the first-stage separation chamber of the oil-water separator through the water flow distribution chamber. In the separation chamber, it flows through a dense laminar flow, increasing the diameter of the oil particles. Then, through the shallow pool principle of the inclined plate, the oil particles are rapidly separated and float to the surface. The oil content index of the effluent is less than 60mg/L.

The reflux pipe extends from the bottom of the aeration zone along the bottom of the air flotation zone. Due to the effect of the vortex aeration machine, there is a negative pressure zone at the bottom of the aeration zone, which causes the wastewater to reflux from the bottom of the air flotation zone to the aeration zone. Then, under the action of microbubbles, it returns to the air flotation zone, completing the reflux. At the same time, oxygen in the air also enters the water, which can stop the oxidation of harmful substances in the water to achieve the purpose of purifying sewage.