纳滤—电渗析处理纤维染色废水反渗透浓水研究

针对反渗透处理纤维染色废水过程中产生的高COD、高色度和高盐含量浓水,研究采用纳滤-电渗析集成技术对其进行脱色、一二价盐分离和盐浓缩中试。结果表明,纳滤膜NF5和NF4分别用于废水脱色和分盐,经过2级纳滤处理后废水色度降低至原水的1/1200,COD从原水的200 mg/L降低至小于100 mg/L,Cl^-和SO4^2-离子的质量浓度比从原水的3:2提高到21:1。电渗析可将纳滤膜NF4透过液中的总溶解盐浓缩至质量分数10%以上。盐浓缩液可重新用于染色,染色效果良好。表明该集成技术在纤维染色废水的深度处理上具备良好的工业化应用前景。

Study on the Nanofiltration-Electrodialysis in the Treatment of Concentrated Water From Reverse Osmosis of Fiber Dyeing Wastewater

Aimed at the high COD,high chroma and high salt content concentrated water produced in the process of reverse osmosis treatment of fibre dyeing wastewater,the nanofiltration-electrodialysis integrated technology was used for this wastewater to decolorize,separate monovalent and bivalent salts and concentrate salt.The results showed that,nanofiltration membranes NF5 and NF4 were used for decolorization and salt separation of wastewater respectively,after two-stage nanofiltration treatment,the chroma of wastewater was reduced to 1/1200 of raw water,the COD was reduced from 200 mg/L to less than 100 mg/L of raw water,and the mass concentration of chloride ion and sulfate ion was increased from 3:2 to 21:1.Electrodialysis could concentrate the mass fraction of total dissolving salt in the permeate of nanofiltration membrane NF4 to more than 10%.The salt concentrate can be used for dyeing again,and the dyeing effect is good,which show that the integrated technology has good industrial application prospects in advanced treatment of fiber dyeing wastewater.