The main pollutant in the wastewater of machinery factories is oil, and different processes are used to remove them according to the different forms of oil in the wastewater.
1. Removal of oil slick
The slick oil is separated by the grease trap and recovered by the slick oil recovery machine. The machine relies on a lipophilic and hydrophobic ring-shaped oil collecting drag, which is mechanically driven to continuously rotate on the oil-water surface at a certain speed to adhere the oil from the oily sewage and squeeze the oil off by the squeezing roller In the oil tank, it is then sent to the dehydration tank by the oil pump for dehydration, and the slick oil is sold outside. 400kg of slick oil can be recovered every day, and the total amount for external sales is 600 yuan.
2. Removal of emulsified oil
The emulsified oil contained in the wastewater is removed by air flotation after demulsification. Air floatation adopts CAF vortex air floatation. Compared with dissolved air flotation, it has the advantages of simple structure, convenient operation and lower power consumption. With the same processing capacity of 150m3/h, the total power of CAF is 2.94kW, while the total power of dissolved air flotation is above 20kW.
3. Removal of dissolved organic matter
The soluble oil and other organic matter remaining in the wastewater are finally treated by biochemical methods. Because the COD concentration of the raw water is not high, the biological contact oxidation process with stable operation and simple operation is selected. The designed residence time is 4h, and the reactor has built-in composite fillers. , Using blast aeration. After solid-liquid separation of the effluent through the inclined tube sedimentation tank, the supernatant is discharged outside the standard.