Real Dyeing And Finishing Wastewater Treatment By Combined Anaerobic Processes

Printing and dyeing wastewater has the characteristics of high chroma,high organic content,poor biodegradability,also contains toxic substances.It is an industrial wastewater with high difficulty in treatment.The anaerobic process has great potential advantages for the better removal of dyes and chroma in printing and dyeing wastewater.In this study,an anaerobic membrane bioreactor(An MBR)and an anaerobic sequential batch reactor(An SBR)were compared.The main process combined with anaerobic membrane bioreactor(An MBR)was selected to combine high-pressure membrane(NF/RO)and lack The aerobic process treats the actual printing and dyeing wastewater,examines the pollutant removal efficiency and optimizes the operating conditions of each process to meet the relevant industry discharge or reuse standards,and provides technical support for the treatment and reuse of printing and dyeing wastewater.The anaerobic membrane bioreactor(An MBR)has a COD removal rate of 85%-91%,an effluent COD of 120-140 mg / L,and an effluent color of 25 times,which are superior to anaerobic sequential batch reactors(COD removal rate of 45%-75%,effluent COD 260-600 mg / L,effluent color 50 times).Due to the complete retention of the sludge flocs by microfiltration membranes and the efficient retention of macromolecular organics,An MBR can maintain a good COD removal rate at volume loads up to 6.6 g COD / L / d.With the extension of the running time,the abundance of An MBR’s microbial population showed a downward trend,and the main bacterial species were Bacteroides and Proteobacteria.An MBR effluent is treated with high-pressure membrane(NF / RO).When the NF recovery rate is 70%,the effluent COD,total phosphorus,total nitrogen,aniline,conductivity,and ammonia nitrogen all meet the indirect discharge standards for printing and dyeing wastewater;when the RO recovery rate is 70 %,The effluent COD,total phosphorus,total nitrogen,ammonia nitrogen,conductivity,aniline reaches the printing and dyeing wastewater direct discharge standard and printing and dyeing rinse water reuse standard.The classic filtration model shows that NF and RO are dominated by filter cake layer pollution.The An MBR effluent was treated with anoxic / aerobic alternating SBR,and the average COD(74 mg / L),ammonia nitrogen(0.7 mg / L)and total phosphorus(0.29 mg / L)of the effluent met the direct discharge standards of printing and dyeing wastewater due to denitrification carbon Insufficient sources cause the total effluent nitrogen(29.5 mg / L)to exceed discharge standards.In the external glucose carbon source mode,the treatment effect is the best when the ratio of actual and theoretical dosage is 3,the average COD(79 mg / L),ammonia nitrogen(0.4 mg / L),and total nitrogen(13.5 mg / L),Total phosphorus(0.14 mg / L)and chromaticity meet the direct discharge standard of printing and dyeing wastewater.For the purpose of meeting the discharge standards,An MBR and anoxic / aerobic SBR can use various pollutants in the effluent to meet the direct discharge standards of printing and dyeing wastewater;An MBR and high-pressure membrane(RO)can meet the standards of rinsing and reuse water,and achieve the printing and dyeing wastewater return use.