Water Laboratory, RheinEnergie AG, Parkgürtel 24, 50823, Köln, Germany; Department of Ecosystem Analysis, Institute for Environmental Research, ABBt-Aachen Biology and Biotechnology, RWTH Aachen University, Worringerweg 1, 52074, Aachen, Germany.
DVGW-Technologiezentrum Wasser (TZW), Karlsruher Straße 84, 76139, Karlsruhe, Germany.
Water Res. 2019 Apr 15;153:357-368. doi: 10.1016/j.watres.2019.01.018. Epub 2019 Jan 28.
The monitoring and control of drinking water quality is generally important as it significantly contributes to the health of the population. In this context, particular attention has to be paid to the use of treatment techniques during drinking water treatment. It is known that the formation of reaction products (transformation products) has to be taken into account when oxidizing agents such as ozone are used. Different transformation products are classified as critical to health and require analytical examination. The risk assessment for previously unknown transformation products can be difficult as far as not all transformation products are present as single substances or the individual substances are not present in a sufficient high concentration or cannot be isolated from the original solution. The aim of this work is to show exemplarily the identification and quantification of ozonation products (OPs) after ozonation and their toxicological characterization, using the artificial sweetener acesulfame. It was shown that OPs can be fully characterized using ion chromatography in combination with different detection systems. A major OP could be recovered as a pure substance by crystallization and direct genotoxicological testing was possible without previous enrichment processes. Acesulfame samples of different concentrations in ultrapure and in drinking water after ozonation were tested in several genotoxicity tests. These tests revealed genotoxic effects of acesulfame after ozonation in ultrapure water in several genotoxicological test systems (micronucleus test, umu test, Ames-fluctuation-test and comet assay). In contrast, the crystallized ozonation product OP168 did not show any positive effects. Therefore, it seems likely that the observed effect was caused by the second major product OP170. However, a sufficiently large amount of analytically pure substance OP170 could not be obtained. It was also shown that the rate of the OP170 formation in drinking water is significantly lower than in ultrapure water and that ozonation in drinking water did not induce genotoxic effects.
饮用水水质的监测和控制通常非常重要，因为它对人口健康有重大影响。在这方面，在饮用水处理过程中使用处理技术时必须特别注意。众所周知，在使用臭氧等氧化剂时，必须考虑到反应产物（转化产物）的形成。不同的转化产物被归类为对健康有重大影响的物质，需要进行分析检查。对于以前未知的转化产物，风险评估可能很困难，因为并非所有转化产物都以单一物质的形式存在，或者个别物质的浓度不够高，或者不能从原始溶液中分离出来。本工作的目的是使用人工甜味剂乙酰磺胺酸钾为例，展示臭氧氧化后臭氧氧化产物（OPs）的鉴定和定量及其毒理学特征。结果表明，使用离子色谱法结合不同的检测系统可以对 OPs 进行全面表征。可以通过结晶回收主要 OP，并可以在无需先前富集过程的情况下直接进行遗传毒性测试。对臭氧氧化后超纯水和饮用水中不同浓度的乙酰磺胺酸钾进行了多项遗传毒性测试。这些测试在几个遗传毒性测试系统（微核试验、umu 试验、Ames 波动试验和彗星试验）中揭示了臭氧氧化后超纯水中乙酰磺胺酸钾的遗传毒性作用。相比之下，结晶的臭氧氧化产物 OP168 没有显示出任何阳性效果。因此，观察到的效果似乎很可能是由第二种主要产物 OP170 引起的。然而，无法获得足够量的分析纯物质 OP170。还表明，OP170 在饮用水中的形成速度明显低于超纯水，并且臭氧氧化在饮用水中没有诱导遗传毒性作用。
