Study On High Salinity Wastewater Treatment Technology In Refining And Chemical Enterprises

With the continuous development of China's oil refining industry,pollutant emissions from the industry is increasingly serious,especially high salinity wastewater with salt content higher than 1.0% wt,which is prone to excessive emissions that lead to water pollution because it is difficult to process.Water pollution not only exacerbates the reducing fresh water resourcesand seriously damages the natural ecological environment,but also threatens the safety of drinking water,so there is an urgent need to find an economical and efficient treatment technology to help refining enterprises discharge high salinity wastewater by standards and alleviate the deteriorating ecological and environmental conditions.In this paper,the research is conducted on the high salinity wastewater treatment technology at home and abroad.The paper analyzes the quantity and quality of high salinity wastewater produced by the Sinopec Qingdao Refining and Chemical Company,and explores the high salinity wastewater processing technology that suits the Company.The selected high salinity wastewater treatment technology was tested at Sinopec Qingdao Refining and Chemical Company.At Sinopec Qingdao Refining and Chemical Company,high salinity wastewater was divided into two parts for treatment,either having lived up to thedischarge standards.The circulating water and chemical water with salt content less than 1.5%wt and high hardness were tested for hardness with the multi-stage floc sedimentation system,and the CFB Boiler desulfurization and denitrification wastewater and catalytic cracking desulfurization and denitrification wastewater which with salt content up to 7.7 %wt were processed using the United States Enscrub? biochemical treatment technology and tested for denitrification and COD removal.After nearly a year of experimental verification,multi-stage floc sedimentation system is proven effective in softening wastewater,the total water hardness no greater than 1500mg/L,the total alkalinity no greater than 500mg/L of the case,the water can reach the total hardness no greater than 400mg/L,total hardness + alkalinity no greater than 800mg/L water quality,can meet the requirement for biochemical treatment of water in the next step;Enscrub? biochemical treatment technology can meet the water quality requirements of COD no greater than 45mg/L,ammonia nitrogen no greater than 4mg/L,total nitrogen no greater than 25mg/L under the conditions of influent salt content not higher than 7.7% wt and meeting the national discharge standards.