| With the progress of technology in recent years,nanofiltration technology has developed rapidly and has been widely used in many fields.As a common problem in industrial wastewater treatment,the treatment of high concentration organic wastewater has always been a key and difficult point.How to treat high concentration organic wastewater more effectively and economically is an important issue in research areas such as sewage deep treatment and pollution zero emission.Nanofiltration membrane separation process is chosen to filter the high concentration organic wastewater generated by chemical plant in this paper.After the contrast of salt rejection performance and separation performance between the two kinds of nanofiltration membrane module,the optimal membrane is selected to perform orthogonal experiment which is aimed to analysis the interaction of operational factors,and then the model equations and optimal values are thus obtained.As a result:(1)NF2 membrane has a better ability to separate salt and shows better stability in the process.Both films can well tolerate the organic wastewater with high concentration,and the Suspended Substance(SS)of the raw water is the most important factor impacting the flux and the life span of membrane.As the organics retention rate of NF1 membrane is up to 80% and the NF2 membrane is only 50%,the NF1 membrane is selected ultimately to perform optimization analysis.(2)Pressure is the most significant factor affecting the retention rate of the membrane,and flow rate is relatively less significant factor,and then comes the salt content in water samples.(3)With the analysis of response surface obtained by orthogonal experiment,the optimum operating condition for pressure is determined as 1.43 MPa,and flow rate of raw water is 2.2 LPM,and COD retention rate is up to 86.35%,and chlorine ion permeability is up to 132%.Under the experimental condition,the recovery rate of single 1812 membrane is 10.3%. |
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