Inorganic Chemicals Industry ›› 2026, Vol. 58 ›› Issue (1): 84-91.doi: 10.19964/j.issn.1006-4990.2024-0611

• Environment·Health·Safety • Previous Articles     Next Articles

Study on resourceful reuse technology of sodium carbonate in concentrated water of reverse osmosis for textile dyeing and printing

WANG Xihui1(), WANG Haitao1, XU Yinong3, CHEN Donggen3, LIU Peng3, CHEN Dongmei3, REN Qicheng1, LI Zhonghua3(), CHANG Na2()   

  1. 1. School of Environmental Science and Engineering,Tiangong University,Tianjin 300387,China
    2. School of Chemical Engineering and Technology,Tiangong University,Tianjin 300387,China
    3. Zhejiang ;Jinmo Environmental Technology Co. ,Ltd. ,Shaoxing 312000,China
  • Received:2024-11-19 Online:2026-01-10 Published:2026-01-20
  • Contact: LI Zhonghua, CHANG Na E-mail:wl15138691971@163.com;2245959664@qq.com;changna@tiangong.edu.cn

Abstract:

The concentrated water from the reverse osmosis(RO) process in the dyeing and printing industry is characterized by high organic content,high alkalinity,and complex salt composition.The main inorganic salts in it are a complex system of sodium sulfate(Na2SO4),sodium carbonate(Na2CO3),and sodium bicarbonate(NaHCO3).In response to the current situation where the technology for recovering sodium sulfate was mature but the resource utilization of high⁃value sodium carbonate was insufficient,an integrated process of "ultrafiltration(UF)+advanced oxidation process(AOP) with ozone+nanofiltration(NF)" was innovatively used to focus on the separation and recovery of sodium carbonate from the complex system.The results showed that the "UF+AOP" pretreatment stage achieved a color removal rate of 98.87% and a COD removal rate of 88.91%,effectively ensuring the stable operation of the NF system.After adjusting the pH by adding acid to convert CO32- to HCO3-,the NF system,operating at 1.6 MPa,it reached a rejection rate of 93.42% for SO42- and 16.78% for HCO3-.By adjusting the pH with alkali to convert HCO3- back to CO32-,the separation of Na2SO4 and NaHCO3 was achieved.The process verification indicated that the entire system operated stably and reliably.This study had established a new method for the selective recovery of valuable inorganic salts from dyeing and printing RO concentrated water,providing a solution with engineering application value for the textile and dyeing industry to achieve zero wastewater discharge and resource recycling,with significant environmental and economic benefits.

Key words: reverse osmosis concentrated water, high alkalinity, advanced oxidation of ozone, nanofiltration, sodium carbonate

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