Chlorination of natural organic matter: kinetics of chlorination and of THM formation
Chlorination of natural organic matter: kinetics of chlorination and of THM formation
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DOI：
10.1016/s0043-1354(01)00187-7
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发表时间：
2002-01-01
期刊：
影响因子：
12.8
通讯作者：
von Gunten, U
中科院分区：
文献类型：
--
作者：
Gallard, H;von Gunten, U
研究了天然有机物在过量氯(50um>；[Cl2](O)>；210um)氯化过程中三卤代甲烷(THMs)的生成和氯耗动力学。THM前体可分为快速反应组分和缓慢反应组分。长期需氯量和THM的形成可用二级动力学来描述。在pH 7~9范围内，地表水和地表水中的腐殖质的速率常数在0.01~0.03M-1 S(-1)之间。A地下水的速率常数较高，为0.124 M-1，S(-1)。对间苯二酚类结构进行了THM生成动力学和产率的测试。它们可能是快速反应的THM前体的原因，占天然水域THM前体的15%-30%。其他类别的化合物可能有助于最初的THM的形成，包括容易烯化的化合物，如β-二酮和β-酮酸。与苯酚的实验表明，缓慢反应的THM前体可能由酚类化合物组成。研究了紫外线/可见光照射、臭氧和二氧化氯等前处理对NOM的氯需量和THM生成的影响：UV/可见光照射不会改变THM的生成，但会导致更高的氯需求量。臭氧预氧化可减少THM的生成，但需氯不变，二氧化氯预氧化可减少THM的生成和氯需求。(C)2001爱思唯尔科学有限公司。保留所有权利。
The kinetics of the formation of trihalomethanes (THMs) and of chlorine consumption for the chlorination of natural organic matter with an excess of chlorine (50 muM > [Cl-2](o) > 210 muM) was investigated. THM precursors could be divided into a fast and a slowly reacting fraction. Long term chlorine demand and the formation of THM could be described by second order kinetics. Rate constants were between 0.01 and 0.03 M-1 s(-1) in the pH range 7-9 for surface waters and humic materials extracted from surface waters. A groundwater gave a higher rate constant of 0.124 M-1 s(-1). Resorcinol-type structures were tested with respect to kinetics and yield of THM formation. They could possibly be responsible for the fast reacting THM precursors, which represent 15-30% of the THM precursors of natural waters. Additional classes of compounds that might contribute to the initial THM formation include readily enolizable compounds such as beta -diketones and beta -ketoacids. Experiments with phenol showed that slowly reacting THM precursors may consist of phenolic compounds. The influence of pretreatments (UV/visible irradiation, ozone and chlorine dioxide) on chlorine demand and THM formation from NOM was also studied: UV/visible irradiation does not alter THM formation but leads to a higher chlorine demand. Preoxidation with ozone leads to a lower THM formation with an unaltered chlorine demand and preoxidation with chlorine dioxide reduces THM formation and the chlorine demand. (C) 2001 Elsevier Science Ltd. All rights reserved.