Abstract： The original pretreatment process of the sewage treatment station of a coking factory in Qinghai Province was ceramic membrane filtration + ammonia evaporation. Raw water was filtered directly into the ceramic membrane filter and then entered the ammonia evaporation system, resulting in an increase in the operating load of the ceramic membrane, blockage of the tray structure of the ammonia evaporation system, and low ammonia evaporation efficiency. During operation, it had a great influence on the adjustment of ammonia evaporation load and the standard control of ammonia evaporation wastewater. The low efficiency of ammonia evaporation also makes it difficult for the ammonia evaporation wastewater to meet the intake index requirements of the water treatment biochemical unit. Moreover, due to frequent maintenance, the remaining ammonia water cannot be effectively processed by the ammonia evaporation system, which eventually leads to the occurrence of high liquid level and difficult consumption in the accident ponds and tanks. It also leads to frequent replacement of ceramic film during operation, increasing labor intensity. Therefore, it is necessary to transform the pretreatment facilities, remove the suspended matter and most oil substances in the water before the wastewater enters the ceramic membrane facilities, reduce the subsequent operating pressure, and ensure the stable discharge of coking wastewater in the plant.The results show that the effluent effect is good after upgrading.
