Ozonation as an efficient pretreatment method to alleviate reverse osmosis membrane fouling caused by complexes of humic acid and calcium ion  

作　　者：Xuehao Zhao Yinhu Wu Xue Zhang Xin Tong Tong Yu Yunhong Wang Nozomu Ikuno Kazuki Ishii Hongying Hu 

机构地区：[1]Environmental Simulation and Pollution Control State Key Joint Laboratory,State Environmental Protection Key Laboratory of Microorganism Application and Risk Control (SMARC),School of Environment,Tsinghua University,Beijing 100084,China [2]Collaborative Innovation Center for Advanced Nuclear Energy Technology,Institute of Nuclear and New Energy Technology,Tsinghua University,Beijing 100084,China [3]Kurita Water Industries Ltd.,Nakano-ku,Tokyo 164-0001,Japan [4]Shenzhen Environmental Science and New Energy Technology Engineering Laboratory,Tsinghua-Berkeley Shenzhen Institute,Shenzhen 518055,China

出　　处：《Frontiers of Environmental Science & Engineering》2019年第4期89-100,共12页环境科学与工程前沿（英文）

基　　金：funded by the National Key Research and Development Program of China (Grant No. 2016YFE0118800);Key Program of the National Natural Science Foundation of China (No.51738005).

摘　　要：Humic acid has been considered as one of the most significant sources in feed water causing organic fouling of reverse osmosis (RO) membranes, but the relationship between the fouling behavior of humic acid and the change of its molecular structure has not been well developed yet. In this study, the RO membrane fouling behavior of humic acid was studied systematically with ozonation as a pretreatment method to control RO membrane fouling. Furthermore, the effect of ozone on the structure ofhumic acid was also explored to reveal the mechanisms. Humic acid alone (10-90 mg/L, in deionized water) was found not to cause obvious RO membrane fouling in 45-h operation. However, the presence of Ca^2+ aggravated significantly the RO membrane fouling caused by humic acid, with significant flux reduction and denser fouling layer on RO membrane, as it was observed by scanning electron microscope (SEM) and atomic force microscope (AFM). However, after the pretreatment by ozone, the influence of Ca^2+ was almost eliminated. Further analysis revealed that the addition of Ca^2+ increased the particle size of humic acid solution significantly, while ozonation reduced the SUVA254, particle size and molecular weight of the complexes of humic acid and Ca^2+(HA-Ca^2+ complexes). According to these results and literature, the bridge effect of Ca^2+ aggregating humic acid molecules and the cleavage effect of ozone breaking HA-Ca^2+ complexes were summarized. The change of the structure of humic acid under the effect of Ca^2+ and ozone is closely related to the change of its membrane fouling behavior.

关 键 词：Reverse osmosis Membrane FOULING HUMIC acid Ca^2+ Ozone 

分 类 号：T[一般工业技术]