Abstract:

In order to reduce the discharge of oily sewage and salty sewage, the combination process of high-density sedimentation tank + ozone catalytic oxidation + improved multi-stage biological filter + micro-sand and carbon high efficiency sedimentation tank is adopted to improve the utilization rate of water resources and reduce pollutant emissions. This paper introduces the process flow of the transformation project, optimizes the operating conditions of ozone generation and filter backwashing, and adjusts the source of back-blowing air and carbon source. Practical operation shows that after the use of this combined process, the TP, cyanide, ammonia nitrogen and volatile phenol of the external drainage are reduced by more than 97%, 95%, 83% and 72% respectively, and the amount of discharged pollutants is significantly reduced. The drainage water quality fully meets the discharge limit requirements of DB 61/224—2018 Integrated wastewater discharge standard of Yellow river basin in Shaanxi province, and the COD is stable at 17～19 mg/L. It has obvious energy saving and consumption reduction effect, and good environmental, social and economic benefits, which can provide reference for domestic similar projects.

Key words: refining wastewater, advanced treatment, ozone catalytic oxidation, biological aerated filter, ozone release, backwashing wastewater, air supply of degassing tank, carbon source filling

摘要：

延安炼油厂为减少含油污水、含盐污水外排，在工业废水提标改造项目中采用高密度沉淀池-臭氧催化氧化-改良多级生物滤池-微砂加炭高效沉淀池组合工艺，以提高水资源利用率，减少污染物排放。介绍了改造工程的工艺流程，包括优化臭氧发生、滤池反洗运行条件，调整反吹风来源、碳源等。实际运行显示，采用该组合工艺后，外排水的总磷、氰化物、氨氮、挥发酚排放量分别降低97%,95%,83%,72%以上，外排污染物减量明显，排水水质完全满足DB 61/224—2018《黄河流域(陕西省)污水综合排放标准》中排放要求，COD(化学需氧量)稳定在17～19 mg/L之间，节能降耗效果明显，环境、社会与经济效益良好，可为国内同类项目提供参考。

关键词: 炼油废水, 深度处理, 臭氧催化氧化, 曝气生物滤池, 臭氧释放量, 反洗废水, 脱气池供风, 碳源加注