Design And Application Of Treatment System For Blowdown From Recirculating Cooling Water

Petrochemical enterprises are major water users,for solving the problem of water shortage of enterprises and reduce the discharge of sewage pollution to the environment,in the process of the sustainable development of enterprises,the treatment and reuse of the blowdown from recirculating cooling water has become an important measure of saving water in the process of production for enterprises.How to choose the appropriate sewage pretreatment and treatment process is the key to ensure effluent standards.Process design of the recirculating cooling water was introduced in this study.The sources and characteristics of blowdown from recirculating cooling water was introduced.Based on current wastewater desalination technologies,water quality of the blowdown from recirculating cooling water in a petrochemical project,and patented technology the company has,a set of blowdown from recirculating cooling water treatment system was designed with efficient,stable treatment effect,and is advantageous to the long-term operation of the equipment,and put into actual operation.The treatment system has run stable for two months.The effluent reaches the reuse standard and was successfully used as the recirculating cooling water.The pretreatment unit includes lamella high performance settler and BS~?unit.Lamella high performance settler is composed of coagulation,flocculation and sedimentation,which are used to remove the organic matter,colloids,suspended particles,hardness,alkalinity,TP and heavy metals in the wastewater.BS~?unit is mainly composed of the pond,BS~?treatment unit and produced pool,which is used to remove the suspended particles,organic matter and bacteria in the wastewater.BS~?technology can effectively intercept biological nutrients within the filter,make the microbes fixed in the filter and reproduction,and can inhibit microbes reproduction in the surface of reverse osmosis membrane,thus effectively prevent reverse osmosis membrane surface biological fouling.The treatment unit includes reverse osmosis unit.The reverse osmosis unit is mainly composed of security filter,high pressure pump and reverse osmosis membrane system.The security filters is used to remove larger impurity particles to protect membrane components.The reverse osmosis membrane system is used to remove inorganic salt,colloidal and organic matter in the wastewater.Designed treatment system has run successfully for two months.Results show that the treatment system for COD,BOD,SS,hardness,alkalinity and TP removal is effective.Effluent turbidity of lamella high performance settler is less than 1.0NTU;the average removal rate of COD is 28.8%;the average removal rate of TP is 97.3%.Effluent turbidity of BS~?unit is less than 0.2NTU;the average removal rate of COD is 20%;the SDI value can maintain at about 3.The treated water quality of reverse osmosis unit conforms to the requirement of quality indicators of the reclaimed water as make-up water for recirculating cooling water system.