有机废水中盐含量对膜蒸馏处理性能的影响

Effect of Salinity in Organic Wastewater on Membrane Distillation Performance

采用真空膜蒸馏技术对高盐有机废水进行浓缩回收。考察了废水进料温度、真空度、进料流速、废水盐度、废水的进料方式等因素对膜通量和截留率的影响。结果表明,在常压循环方式进料,透过侧真空度0.04～0.095 MPa,进料温度为30～80℃,进料流量为40～160 L/h的条件下,通过实验设计的膜蒸馏过程,可以将质量分数为10%盐度的有机废水,COD>7 500×10-6,浓缩至质量分数为30%盐度的有机废水,透过水的盐度<0.01%,COD<20×10-6,通过盐结晶方法去除相应有机物后,可获得纯度较高的工业盐。

Wastewater with high salinity and organic compounds was treated by vacuum membrane distillation（VMD）.Effects of operation conditions on water flux and salt rejection were investigated.The results show that when circulatory feeding at ordinary pressure and 303～553 K,and flow rate is 40～60 L/h,and the vacuum degree is 0.4～0.95 MPa at downstream,the wastewater with high salt concentration（10%） and COD value（7 500×10^-6） can be concentrated to 30%,COD and salt concentration of the permeate are less than 20×10^-6 and 0.01% respectively,after some organic compounds are removed by crystallizing method,the salt with high purity is gained.