影响石油炼制污水稳定运行的因素及对策

Factors Affecting Operational Stability of Refinery Wastewater Treatment System and Countermeasures

《辽宁省污水综合排放标准》(DB 21/1627—2008),要求污水COD值不大于50mg/L,NH3-N不大于8mg/L,这一标准远远高于国家一级排放标准COD值不大于60mg/L,NH3-N不大于15mg/L,辽宁省新标准也是目前国内最为严格的排放标准。坐落于辽宁省的某石化公司污水处理场设计指标是按照国家一级标准设计的,辽宁省新标准的颁布执行,对该污水处理场提出了更高要求。根据工艺流程,上游生产装置排放的含油污水直接进入污水处理场进行处理。污水处理场稳定达标排放影响因素中,上游生产装置排污影响占60%,污水处理场内部的运行优化占40%。这一比例说明加强上游污水监控对于污水处理场运行起到重要作用。因此,污水处理场若要稳定达标,首先要对上游排污情况了解清楚,制定针对性的应对方案,做好源头治理;另外,污水处理场内部还要做好运行监控工作,优化运行,挖掘运行潜力,做好上下游一体化的协调管理,保证出水水质的达标排放。

The Integrated Wastewater Discharge Standard of Liaoning Province （DB 21/1627--2008） re- quires sewage COD value to not exceed 50mg/L and NH3-N to not exceed 8mg/L.This standard is far stricter than the national class one discharge standard,which requires COD value to not exceed 60mg/L and NH3-N to not exceed 15mg/L.The standard is also the strictest in China.A sewage treatment plant of a petrochemical company in Liaoning province was designed according to the national class one standard and the new stan- dard of Liaoning province has set out higher requirements for the sewage treatment plant.According to the technological process of the facility,oily sewage from the upstream production units will be direclty discharged into the sewage treatment plant.Of all the factors affecting the consistent compliance of the water treated by the sewage treatment plant with relevant standards ,the effect of sewage discharge by upstream production u- nits accounts for 60% and the optimization of operation inside the sewage treatment plant accounts for 40%. This ratio suggests that strengthening the monitoring and control of sewage from upstream units plays a key role in ensuring the stahlity of operation of the sewage treatment plant.Therefore,in order to enable the sewage treatment plant to meet the relevant standards in a consistent manner,sewage discharge by upstream units must be fully understood and a plan specific for the sewage discharge should he developed to control the source of sewage discharge.In addtion,the sewage treatment plant itself should well monitor and optimize its operation ,tap the potential of operation and integrate management for upstream and downstream units to ensure that the quality of water treated by the sewage treatment plant meets the relevant discharge standard.