Cyclic coupling of photocatalysis and adsorption for completely safe removal of N-nitrosamines in water. (1st February 2022)

• Record Type: Journal Article
• Authors: Liu, Caini; Zhang, Man; Gao, Huiyu; Kong, Lulu; Fan, Shougang; Wang, Lan; Shao, Huaiqi; Long, Mingce; Guo, Xiaoyan
• Is Part Of: Water research. Volume 209(2022)
• Publication Date: 2022-02-01
• Subjects: N-nitrosamines -- Photocatalysis -- Adsorption -- N-nitrosamines formation potential -- TiO2 nanowire -- HY zeolite; Water -- Pollution -- Research -- Periodicals; 363.7394
• DOI: 10.1016/j.watres.2021.117904
• Languages: English
• ISSNs: 0043-1354

Abstract

Highlights: Immobilized TiO2 /Ti photocatalyst degraded N-nitrosamines into primary and secondary amines. TiO2 /Ti photocatalyst degraded N-nitrosamines by attacking on nitrosyl nitrogen via OH. The nanowire film morphology of TiO2 /Ti played vital roles on degradation of N-nitrosamines. The selective adsorption of degradation products by HY zeolite corresponded to lagergren adsorption rate equation of second order. The cyclic coupling process of photocatalysis and adsorption realized complete and safe removal of N-nitrosamines. Abstract: The incomplete removal of N-nitrosamines in water through current degraded techniques and the carcinogenicity of N-nitrosamines call for alternative complete and safe removal approaches. Here, we describe a cyclic coupling process of photocatalysis and adsorption enabling N-nitrosamines in water thoroughly and safely removed. Among them, the immobilized TiO2 /Ti photocatalyst degraded N-nitrosamines into primary and secondary amines up to 100% by attacking on nitrosyl nitrogen via OH originated from its nanowire film morphology. Furthermore, the affinity of HY zeolite to primary and secondary amines led to efficient adsorption through corresponding to Lagergren adsorption rate equation of second order. And then the cyclic coupling process of photocatalysis and adsorption realized complete and safe removal of N-nitrosamines with various concentration ranging from 0.1 mM to 1 mM in water, significantly higher than the existing reports on the removal rate of N-nitrosamines and the formation potential of N-nitrosamines. This study will lead to new avenues for complete and safe eliminaton of hardly degradable hazardous substances in water. Graphical abstract: Image, graphical abstract