Abstract

The formation and removal of trihalomethanes and trichloroethylene at an existing beverage production enterprise at the stages of the sodium hypochlorite disinfection of water from the centralized drinking waterwork system after treatment with ammonium chloride have been studied. To clarify the mechanism of formation of trihalomethanes and trichloroethylene, the concentrations of organic and organochlorine compounds have been analyzed after each of the three sodium hypochlorite introduction stages alongside with the dynamics of their change in the tap water supplied to the enterprise. It has been shown that the highest amount of organochlorine compounds is formed in the process of filtration on sand filters. The chloroform concentration is ranged within 40–65 μg/dm³, and the trichloroethylene concentration is 34–72 μg/dm³, being respectively 67 and 61% higher than in the tap water. One of the main reasons for the excessive formation of trihalomethanes and trichloroethylene is the disinfection of incoming tap water by means of free chlorine in the presence of a residual amount of chlorine bonded into organic and inorganic chloramines. The mechanism of the excessive formation of organochlorine compounds on sand filters is described as associated with disinfection by means of free chlorine in the absence of ammonium ions and also with a high content of organic compounds in the incoming water and a large dirt absorbing capacity of the filter load. Some variants are proposed for maintaining the optimal chlorination regime at the water aftertreatment stages to provide the formation of a minimum amount of organochlorine compounds, the epidemiological safety of water, the fulfilment of microbiological requirements to filter loads, and the content of residual bonded and free chlorine in the prepared water and its microbiological parameters. To prevent the formation of organochlorine compounds, water disinfection is recommended to perform with the use of hypochlorite with ammonization by ammonium sulfate or with the use of in situ synthesized monochloramine.

中文翻译：

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饮料生产自来水后处理不同阶段三卤甲烷和三氯乙烯的形成与去除

摘要

研究了现有饮料生产企业在氯化铵处理后对集中饮用水系统水进行次氯酸钠消毒阶段三卤甲烷和三氯乙烯的形成和去除。为了阐明三卤甲烷和三氯乙烯的形成机理，在三个次氯酸钠引入阶段的每一个阶段之后，分析了有机和有机氯化合物的浓度，以及它们在供应给企业的自来水中的变化动态。已经表明，在砂滤器的过滤过程中形成的有机氯化合物的量最高。氯仿浓度范围为 40–65 μg/dm ³, 三氯乙烯浓度为 34–72 μg/dm ³，分别比自来水高 67% 和 61%。三卤甲烷和三氯乙烯过量形成的主要原因之一是在残留量的氯结合成有机和无机氯胺的情况下，通过游离氯对流入的自来水进行消毒。在砂滤器上过度形成有机氯化合物的机制被描述为与在没有铵离子的情况下通过游离氯进行消毒以及进水中有机化合物含量高和滤尘器的吸污能力大有关。过滤负载。提出了一些变体，用于在水后处理阶段保持最佳氯化制度，以提供最少量的有机氯化合物的形成，水的流行病学安全，满足过滤负荷的微生物要求，制备的水中残留结合氯和游离氯的含量及其微生物参数。为防止有机氯化合物的形成，建议使用次氯酸盐和硫酸铵氨化或使用原位合成一氯胺进行水消毒。