| With the rapid development of petroleum refining industry,the fresh water resources consumed in the process of crude oil processing increased year by year,causing serious pollution to the water environment.In order to reduce the consumption of fresh water resources and environmental pollution caused by waste water discharged from oil refining,the recycling of waste water from oil refining has become the focus of energy saving and emission reduction in petroleum refining enterprises.The treatment of refinery wastewater can be divided into conventional treatment and deep treatment.The water generated from conventional treatment was treated as raw water for deep treatment.After pretreatment and membrane separation treatment,the water generated can meet different reuse requirements.Petrochina Karamay petrochemical co.,ltd.was located in the northwest of Xinjiang,relatively short of fresh water resources,new water consumption has become a bottleneck restricting the rapid development of enterprises.Since 2006,the company has gradually explored the deep treatment process method of refining wastewater,and carried out the deep treatment and reuse application research of refining wastewater.To a large extent,it alleviated the problem of large amount of new water replenishment in the circulating water system,and made great contributions to the company's energy-saving and water-saving work.The research object of this paper is the secondary standard sewage from the sewage treatment plant of Karamay petrochemical co.,ltd.of petrochina,which has the characteristics of high concentration of COD,petroleum,suspended matter,salt content and other pollutants and complex water quality.The wastewater after the"air flotation+BAF+ozone catalytic oxidation+medium filter"after pretreatment process,through the ultrafiltration and reverse osmosis membrane components processing,from the end of each index of reverse osmosis water production to verify the double membrane process of COD,oil,suspended solids,conductivity,p H,hardness and alkalinity,sulfuric acid root ion,chlorine ion and turbidity index of treatment effect,can inspect water discharged can reach the indexes of the filling water boiler and circulating cooling water system requirements,as well as the influence factors of membrane fouling and control method.During the experiment,under the condition of large treatment capacity,the pretreatment system did not have a good effect on the removal of COD,suspended matter and petroleum in the wastewater,and the removal rate was only between 20%and 30%,which had a great impact on the operation of the subsequent double-film system,resulting in high replacement frequency of filter elements of membrane components and serious membrane pollution.Ultrafiltration and reverse osmosis membrane system can remove more than 95%of pollutants in the water of the pretreatment system.Under the condition of moderate treatment capacity,the pretreatment and double-film system can give full play to the effect to ensure that the inlet and outlet water of each unit meets the design requirements,and the final product water can meet the water quality requirements of boiler and circulating cooling water system.Through the final results and cause analysis of this experiment,it is shown that the ultrafiltration and reverse osmosis double membrane process can realize the deep treatment of refinery wastewater,and the product water can completely meet the water quality standards of boiler and circulating cooling water system,and meet the requirements of reuse.According to the estimation of the experimental equipment,if the treatment capacity of 150m~3/h is maintained after the establishment of the new double-film deep treatment device,the annual treatment capacity of refining wastewater can reach 1.31 million tons,the output of reclaimed water is 880,000 tons,and the fresh water cost is saved by 1.9 million yuan. |
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