关键词: 延迟焦化, 高浓度含油污水, 气浮装置, 除油处理

Abstract: Oily wastewater in refinery delayed coking unit contains a large amount of oil, sulfide and heterocyclic compounds containing nitrogen and oxygen and so forth. It is a kind of refinery wastewater that is difficult to pretreat. Through the development of an integrated micro-nano bubble air flotation technology for oil removal, a new efficient air flotation equipment was adopted to treat the high concentration oily wastewater in a petrochemical delayed coking unit. The industrial application results indicate that the oil, COD and sulfide in wastewater could be reduced to less than 180mg/ L, 2000mg/L, 300mg/L respectively, while the initial contents were 47375mg/L, 82648mg/L and 5100mg/L. The treated wastewater quality was better than the requirements of technical agreement and could be used as cold water in delayed coking unit. There was no effect on the process when the generated scum was sent back to the coke tower. The device operation has ensured the stable operation and wastewater discharging standard of the sewage plant, which could improve the air quality of the refinery and its surrounding.

Key words: delayed coking, high concentration oily wastewater, air floating equipment, oil removal