Reactions of chlorine dioxide with nitrogen-containing pollutants in water treatment: Mechanism and product formation

二氧化氯（ClO2）作为消毒剂和氧化剂在水处理中被广泛应用于污染物控制。然而，其反应机制的主要方面尚不清楚。近年来，有报道称ClO2可作为二次氧化剂形成游离有效氯，影响污染物的副产物和转化产物的形成和氧化。本文研究了ClO2与含氮污染物的反应，含氮污染物占水生环境污染物的很大一部分。计划工作的目的是了解ClO2与模型化合物反应的基本步骤，以预测ClO2基过程中更复杂污染物的行为。因此，将研究二级氧化剂（例如，自由可用氯）和无机氯的形成、反应动力学和转化产物的形成以及诸如氧的影响等基本方面。基于这些研究，将建立反应机理，并用于预测复杂模型化合物的降解效率和转化产物的生成。这些预测将与在确定的溶液和实际水系统中使用含n的复杂微污染物的实验所得的产品形成实验数据进行比较。本提案旨在提高对水处理中ClO2反应的整体认识，这将导致水化学和水处理科学领域的重大进展。这对于改善ClO2基水处理中污染物的降解效率以及含n化合物的副产物和转化产物的形成也有很大的帮助。

Chlorine dioxide (ClO2) is widely used in water treatment as disinfectant and oxidant for pollutant control. However, major aspects of its reaction mechanisms are yet unclear. Recently, it was reported that ClO2 may form free available chlorine as secondary oxidant which may affect, by-product- and transformation product formation as well as oxidation of pollutants. The present proposal deals with the reaction of ClO2 with N-containing pollutants which represent a large fraction of pollutants in the aquatic environment. The aim of the planned work is to understand the elementary steps of the reaction of ClO2 with model compounds for prediction of the behaviour of more complex pollutants in ClO2 based processes. Thereby, formation of secondary oxidants (e.g., free available chlorine) and inorganic chlorine species, reaction kinetics and transformation product formation as well as fundamental aspects such as the influence of oxygen will be investigated. Based on these investigations, reaction mechanisms will be established and used to predict the degradation efficiency and transformation product formation of complex model compounds. These predictions will be compared with experimental data on product formation from experiments with complex N-containing micropollutants in defined solutions and real water systems. The present proposal strives to improve the overall understanding of ClO2 reactions in water treatment, which will result in significant advances in the scientific field of water chemistry and water treatment. It will also be very useful to improve ClO2 based water treatment regarding predictions on degradation efficiency of pollutants and by- and transformation product formation of N-containing compounds.