Liu Mengwen, Yang Yuhan, Shi Yiqiao, Shi Caitong, Hu Shiyi, Wang Yadong, Xu Lu, Bai Xue, Shi Xuan, Jin Xin, Jin Pengkang
School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi Province 710049, China.
School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi Province 710049, China.
Water Res. 2025 Sep 1;283:123880. doi: 10.1016/j.watres.2025.123880. Epub 2025 May 24.
Removal of organic matter in hypersaline reverse osmosis concentrate (ROC) poses significant challenges. In this study, the hybrid microbubble ozonation-coagulation (HOC) process was established for actual hypersaline ROC treatment from energy chemical industry. In this HOC process, the hypersaline environment facilitated the formation of microbubbles, which enhanced ozone mass transfer and ensured an adequate dissolved ozone concentration. Efficient organic removal was achieved through a two-stage procedure: a rapid-removal stage dominated by coagulation (≤ 30 min) and a slow-removal stage dominated by ozone oxidation (> 30 min). Moreover, salinity exhibited two-sided effect on oxidation and coagulation in the HOC process. In the first stage of the treatment process, the alkaline conditions in hypersaline environment promoted oxidation and coagulation through increased •OH production and polymerized Al species generation. However, as the pH decreased owing to coagulant hydrolysis, excessive anions in hypersaline environment inhibited both oxidation and coagulation processes by quenching •OH and promoting large floc generation in the second stage. Furthermore, the two-stage organic removal mechanism was elucidated from the perspectives of oxidative transformation and floc entrapment. In the first stage, high-coagulability organics were directly removed through enhanced coagulation. Meanwhile, low-coagulability organics were oxidized into high-coagulability structures, which were removed via coagulation. In the second stage, organic matter was mainly removed through molecular ozone oxidation, while the coagulation process was inhibited. This study unveiled the two-sided effect of hypersaline environment on oxidation and coagulation, and provided new approaches for enhanced organic removal in the ozone-based process for hypersaline wastewater.
去除高盐反渗透浓水（ROC）中的有机物面临重大挑战。在本研究中，建立了混合微泡臭氧化 - 混凝（HOC）工艺用于处理能源化工行业的实际高盐ROC。在该HOC工艺中，高盐环境促进了微泡的形成，增强了臭氧传质并确保了足够的溶解臭氧浓度。通过两个阶段实现了高效的有机物去除：以混凝为主导的快速去除阶段（≤30分钟）和以臭氧氧化为主导的缓慢去除阶段（>30分钟）。此外，盐度在HOC工艺中对氧化和混凝表现出双重影响。在处理过程的第一阶段，高盐环境中的碱性条件通过增加•OH生成和聚合铝物种的产生促进了氧化和混凝。然而，由于混凝剂水解导致pH降低，高盐环境中过量的阴离子在第二阶段通过淬灭•OH和促进大絮体生成抑制了氧化和混凝过程。此外，从氧化转化和絮体截留的角度阐明了两阶段有机物去除机制。在第一阶段，高凝聚性有机物通过强化混凝直接去除。同时，低凝聚性有机物被氧化成高凝聚性结构，通过混凝去除。在第二阶段，有机物主要通过分子臭氧氧化去除，而混凝过程受到抑制。本研究揭示了高盐环境对氧化和混凝的双重影响，并为强化高盐废水臭氧处理过程中的有机物去除提供了新方法。
