高盐有机废水真空膜蒸馏处理中膜污染的微纳米气泡控制研究

为探究真空膜蒸馏处理高盐废水过程中有机物和盐类对膜污染的贡献以及微纳米气泡对不同类型膜污染的控制作用，选取腐殖酸、牛血清蛋白、海藻酸钠为典型有机污染物代表，分别考察单一有机物、有机物与盐共存对膜污染的影响以及采用微纳米气泡曝气对上述情况产生的膜污染的控制作用。结果表明：3种有机物中，海藻酸钠造成的膜污染最严重，当海藻酸钠浓度为100 mg/L时，真空膜蒸馏系统运行7 h后，相对膜通量降至67.07%；腐殖酸与盐共存造成的复合污染最严重，当进料液腐殖酸浓度分别为10、50和100 mg/L时，系统运行7 h后，相对膜通量分别降至36.33%、33.15%和20.59%；3种有机物与盐共存时，造成的膜污染比单一有机物与盐共存时更严重；微纳米气泡可以有效控制有机物与盐共存时对真空膜蒸馏系统造成的复合污染。

Study on micro-nanobubble control of membrane fouling in vacuum membrane distillation of high salt organic wastewater

In order to explore the contribution of organics and salts to membrane fouling and the control effect of micro-nanobubbles on different types of membrane fouling in the treatment of high salt wastewater by vacuum membrane distillation, three typical organic pollutants, humic acid, bovine serum protein and sodium alginate, were selected to investigate the influence of single organic matter, the coexistence of organic matter and salt on membrane pollution and the control effect of micro-nanobubble aeration on membrane pollution. The results showed that the membrane pollution caused by sodium alginate was the most serious among the three organic compounds. When the sodium alginate concentration was 100 mg/L, the relative membrane flux decreased to 67.07% after 7 h of vacuum membrane distillation system operation. When the humic acid concentration of feed solution was 10, 50 and 100 mg/L, the relative membrane flux decreased to 36.33%, 33.15% and 20.59%, respectively, after 7 h of system operation. When three organic compounds coexisted with salt, the membrane pollution was worse than that when single organic compound coexisted with salt. Micro-nanobubbles could effectively control the compound pollution caused by organic-salt coexistence in vacuum membrane distillation system.