An integrated approach using ozone nanobubble and cyclodextrin inclusion complexation to enhance the removal of micropollutants

WATER RESEARCH

卷:196

Article

Fan, Wei¹  An, Wengang¹  Huo, Mingxin¹  Xiao, Dan²  Lyu, Tao³  Cui, Jingyu¹ 

[1] Northeast Normal Univ, Sch Environm, 2555 Jingyue St, Changchun 130117, Peoples R China

[2] Jilin Acad Agr Sci, 1363 Shengtai St, Changchun 130033, Peoples R China

[3] Cranfield Univ, Cranfield Water Sci Inst, Coll Rd, Cranfield MK43 0AL, Beds, England

关键词: Advanced oxidation;    Chlorophenol;    Emerging organic contaminants;    Hp beta cd;    Inclusion complex;   

DOI  :  10.1016/j.watres.2021.117039

来源: Elsevier

【 摘 要 】

Ozone (O-3) has been widely used for the elimination of recalcitrant micropollutants in aqueous environments, due to its strong oxidation ability. However, the utilization efficiency of O-3 is constrained by its low solubility and short half-life during the treatment process. Herein, an integrated approach, using nanobubble technology and micro-environmental chemistry within cyclodextrin inclusion cavities, was studied in order to enhance the reactivity of ozonisation. Compared with traditional macrobubble aeration with O-3 in water, nanobubble aeration achieved 1.7 times higher solubility of O-3, and increased the mass transfer coefficient 4.7 times. Moreover, the addition of hydroxypropyl-beta-cyclodextrin (HP beta CD) further increased the stability of O-3 through formation of an inclusion complex in its molecule-specific cavity. At a HP beta CD:O-3 molar ratio of 10:1, the lifespan of O-3 reached 18 times longer than in a HP beta CD-free O-3 solution. Such approach accelerated the removal efficiency of the model micropollutant, 4-chlorophenol by 6.9 times, compared with conventional macrobubble ozonation. Examination of the HP beta CD inclusion complex by UV-visible spectroscopy and Nuclear Magnetic Resonance analyses revealed that both O-3 and 4-chlorophenol entered the HP beta CD cavity, and Benesi-Hildebrand plots indicated a 1:1 stoichiometry of the host and guest compounds. Additionally, molecular docking simulations were conducted in order to confirm the formation of a ternary complex of HP beta CD:4-chlorophenol:O-3 and to determine the optimal inclusion mode. With these results, our study highlights the viability of the proposed integrated approach to enhance the ozonation of organic micropollutants. (C) 2021 Elsevier Ltd. All rights reserved.

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