Abstract

N-Nitrosamines, well-known human carcinogens, are widely considered to be formed through the disinfection of waters containing compounds with amine moieties. The formation mechanisms of nitrosamines during the disinfection of drinking water and wastewater have been previously reviewed in the literature. However, no study to date has reviewed the effects of inorganic ions on nitrosamines formation during disinfection. Inorganic ions are ubiquitous in the environment and are present at significant concentrations in water and wastewater. Their presence influences aqueous nitrosamines formation, depending on the type, concentration, and environmental conditions. In this review, we have critically reviewed nitrosamines’ precursors and occurrence, disinfection processes associated with nitrosamines’ formation/destruction, and the impact of inorganic ions on the formation or removal of nitrosamines during disinfection of water and wastewater. The disinfectants reviewed in the study were chlorine, chloramine, chlorine dioxide, ozone, and radicals generated through advanced oxidation processes (AOPs). N-Nitrosodimethylamine formation pathways, in the presence and absence of inorganic ions, were also reviewed to summarize our current understanding. Although chloramination has been associated with the formation of nitrosamines, many ozonation studies have also shown significant levels of nitrosamines formation. Pre-oxidation and AOPs have been reported as the most promising mitigation strategies for controlling nitrosamines formation, requiring prolonged exposure of precursors for effective mineralization.

摘要

ñ-亚硝胺是众所周知的人类致癌物，被广泛认为是通过对含有胺基化合物的水进行消毒而形成的。此前已有文献综述了饮用水和废水消毒过程中亚硝胺的形成机制。然而，迄今为止还没有研究回顾无机离子对消毒过程中亚硝胺形成的影响。无机离子在环境中无处不在，并且以显着浓度存在于水和废水中。它们的存在会影响亚硝胺水溶液的形成，具体取决于类型、浓度和环境条件。在这篇综述中，我们批判性地回顾了亚硝胺的前体和发生、与亚硝胺形成/破坏相关的消毒过程，以及无机离子对水和废水消毒过程中亚硝胺形成或去除的影响。研究中审查的消毒剂是氯、氯胺、二氧化氯、臭氧和通过高级氧化过程 (AOP) 产生的自由基。还回顾了在存在和不存在无机离子的情况下N -亚硝基二甲胺的形成途径，以总结我们目前的理解。尽管氯胺化与亚硝胺的形成有关，但许多臭氧化研究也表明亚硝胺的形成水平很高。据报道，预氧化和 AOPs 是控制亚硝胺形成的最有希望的缓解策略，需要长时间暴露前体才能有效矿化。