含次氯酸钠的膜生产废水处理工艺研究

针对含次氯酸钠(NaClO)膜生产废水具有氧化性强、盐含量高、COD高的特点,采用还原预处理与减压膜蒸馏(VMD)相结合的工艺对其进行处理,研究了不同还原工艺的还原效果,进料温度、冷侧真空度、蒸馏时间、原水有效氯含量对VMD效果的影响。结果表明,亚硫酸钠水溶液还原性能最好;升高进料温度及冷侧真空度都有利于产水通量和盐、COD截留率的提高;蒸馏时间及原水有效氯含量增加均导致产水通量和盐、COD截留率下降;VMD工艺条件对盐截留率的影响较小;在得到的较优VMD工艺条件下,不同有效氯含量的废水的盐截留率均接近100%,COD去除率也高达92%。

Study on the Treatment Technology of Membrane Industrial Wastewater Containing Sodium Hypochlorite

Aimed at the membrane industrial wastewater containing sodium hypochlorite (NaClO) has the characteristics of strong oxidation, high salt content and high COD, combined technology of reduction pretreatment and vacuum membrane distillation (VMD) was used for wastewater treatment. The reduction performance of different reductants, and the effects of feed temperature, cold side vacuum degree, distillation time and effective chlorine content in raw water on VMD performance were investigated. The results showed that sodium sulfite (Na2SO3) aqueous solution had the best reduction performance; the increase of feed temperature and cold side vacuum degree were beneficial to improving water flux, salt rejection ratio and COD rejection ratio; the increase of distillation time and the effective chlorine content of feed wastewater resulted in the decrease of water flux, salt and COD rejection ratio; the operating conditions of VMD had little effect on conductivity and conductivity rejection ratio. Under the best operational conditions, all the conductivity rejection ratio of different effective chlorine content of wastewater was closed to 100%, and COD rejection ratio was above 92.00%.