Process Characteristics Of Synergistic Regeneration And Reuse Of Printing And Dyeing Wastewater By Dissolved Ozone Flotation And Bypass Membrane

Recently,the characteristics of high water consumption and high pollution in printing and dyeing industry have gradually become the focus of attention.The lack of water resources makes the recycling of printing and dyeing wastewater inevitable,and the development of recycling technology also makes the scale of recycling of printing and dyeing wastewater gradually expand.Dissolved ozone flotation technology is widely used in the field of wastewater treatment and regeneration because of its advantages of dissolved ozone flotation and mutual promotion.Different from the traditional"double membrane"process,one part of the secondary effluent enters into the"double membrane"system after advanced treatment,and the other part is mixed with the effluent of double membrane process,which is the bypass membrane mode.In view of the problems of over treatment,high energy consumption and low water production rate of traditional double membrane method in wastewater recycling,a collaborative regeneration system of printing and dyeing wastewater Dissolved ozone flotation and bypass membrane was constructed.The operation characteristics of the system under different bypass treatment rates were analyzed,and the technical and economic characteristics of the collaborative regeneration system were evaluated.In order to meet the water quality requirements of the reuse water of textile dyeing and finishing industry?FZ/T01107-2011?and the technical code for wastewater treatment engineering of textile dyeing and finishing industry?HJ471-2009?,this paper compares the concentration change characteristics of pollutants in the reclaimed water under different bypass treatment rates.When the bypass treatment rate is more than 50%,the effluent quality index of the co regeneration of odor oxygen floatation and bypass membrane meets the reuse standard.Compared with the traditional printing and dyeing wastewater regeneration technology,the cost of water treatment per ton of dissolved ozone flotation and bypass membrane system is 2.25 yuan/m³,and the water production rate of the system is70%,which has a good technical economy.Under the condition of optimizing bypass treatment rate,the co regeneration characteristics of dissolved ozone flotation and bypass membrane were analyzed under the condition of secondary effluent quality fluctuation.The results show that the cooperative mode has a strong adaptability to the fluctuation of secondary effluent quality,reducing the COD fluctuation range by 28%on average,and effectively restraining the fluctuation of water quality.When the COD of secondary effluent fluctuates between 102-150mg/L,the removal rates of COD and UV₂₅₄54 are 30±4%and 15±6%respectively,and the maximum removal rate of fluorescent substances is 50%.The secondary effluent is regenerated by the coupling of bypass membrane and dissolved ozone flotation.The removal rate of organic matter and inorganic anion is about 90%and 94%respectively.During the regeneration process,the change of the pressure difference and the membrane flux of RO membrane showed that the dissolved ozone flotation technology can effectively slow down the membrane pollution during RO membrane filtration.Under the condition of dissolved ozone flotation collaborative treatment,the filtration cycle of RO membrane increased from15 days to 28 days in the direct double membrane method,which was nearly 93%.This project puts forward an economic and feasible process of printing and dyeing wastewater regeneration-dissolved ozone flotation and bypass membrane system collaborative regeneration process.The research of this project provides a reference for the application of collaborative regeneration process in printing and dyeing wastewater treatment engineering design,operation management and other aspects.