Cyclic coupling of photocatalysis and adsorption for completely safe removal of N-nitrosamines in water

Caini Liu; Man Zhang; Huiyu Gao; Lulu Kong; Shougang Fan; Lan Wang; Huaiqi Shao; Mingce Long; Xiaoyan Guo

doi:10.1016/j.watres.2021.117904

Cyclic coupling of photocatalysis and adsorption for completely safe removal of N-nitrosamines in water

Water Res. 2022 Feb 1:209:117904. doi: 10.1016/j.watres.2021.117904. Epub 2021 Nov 28.

Authors

Caini Liu¹, Man Zhang¹, Huiyu Gao¹, Lulu Kong¹, Shougang Fan¹, Lan Wang¹, Huaiqi Shao², Mingce Long³, Xiaoyan Guo⁴

Affiliations

¹ Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria/ Tianjin Key Laboratory of Environmental Technology for Complex Trans-Media Pollution/Tianjin Key Laboratory of Environmental Remediation and Pollution Control /College of Environmental Science and Engineering, Nankai University, Tongyan Road 38#, Haihe Education Park, Jinnan District, Tianjin 300350, PR. China.
² College of Material Science and Chemical Engineering, Tianjin University of Science & Technology, Thirteenth Street 29, TEDA, Tianjin 300457, PR. China. Electronic address: shaohq@tstu.edu.cn.
³ College of Environmental Science and Engineering, Key Laboratory for Thin Film and Microfabrication of the Ministry of Education, Shanghai Jiao Tong University, Dongchuan Road 800, Shanghai 200240, PR. China.
⁴ Ministry of Education Key Laboratory of Pollution Processes and Environmental Criteria/ Tianjin Key Laboratory of Environmental Technology for Complex Trans-Media Pollution/Tianjin Key Laboratory of Environmental Remediation and Pollution Control /College of Environmental Science and Engineering, Nankai University, Tongyan Road 38#, Haihe Education Park, Jinnan District, Tianjin 300350, PR. China. Electronic address: guoxyan@nankai.edu.cn.

PMID: 34864621
DOI: 10.1016/j.watres.2021.117904

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.

Keywords: Adsorption; HY zeolite; N-nitrosamines; N-nitrosamines formation potential; Photocatalysis; TiO(2) nanowire.