Pretreatment system and pretreatment method for oily waste water

The invention discloses a pretreatment system and a pretreatment method for oily waste water. The pretreatment system comprises an oil product synthesis regulation tank, a comprehensive regulation tank, a biochemical treatment unit, several pretreatment tanks, a separation tank, a pretreatment water outlet tank and an anaerobic tank. The pretreatment method comprises the following steps: (1) biochemical pretreatment; (2) anaerobic treatment. The processing system of the invention has the advantages of simple structure and easy realization. The activated sludge is mixed with the oily waste water again, so that the activated sludge fully absorbs the oil in the waste water and reduces the oil content in the waste water. At the same time, the alkali carried in the activated sludge can be returned to the wastewater to adjust the pH value of the wastewater, thereby reducing the amount of alkali added and the cost of wastewater treatment, and avoiding the waste of the activated sludge. 本发明公开了一种含油废水的预处理系统及预处理方法，预处理系统