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利用脉冲辐解技术对 2-氯酚水溶液在多种条件下的降解行为进行了详细研究。对瞬态光谱中的主要吸收作了归属,并考察了这些瞬态产物的生成和衰减动力学。研究表明,在不同 pH 值下,2-氯酚与?OH 的反应途径不同:中性条件下主要生成羟基加成物,其生成速率常数为 8.3×109dm3?mol-1?s-1;碱性条件下,则主要发生电子转移形成 2-氯代酚氧基,同时存在羟基加成物脱 HCl 和脱 OH-过程。?N3与 2-氯酚发生单电子氧化,形成 2-氯代酚氧基。?H 与 2-氯酚发生加成反应生成环己二烯类氢加成物,其速率常数为 2.5×109dm3 ? mol-1 ? s-1。eaq 与 2-氯酚发生电子转移,生成羟苯基和氯离子,碱性条件(pH=11)和中性条件下的速率 -常数分别为 3.5×108 dm3?mol-1?s-1和 2.2×109 dm3?mol-1?s-1。该结果有助于人们进一步了解氯酚降解的本质,从而为该类化合物的降解处理提供了理论基础。
Degradation behavior of 2-chlorophenol aqueous solution under various conditions was studied in detail using pulsed radiolysis technology. The main absorptions in the transient spectra are assigned and the generation and decay kinetics of these transient products are examined. The results showed that the reaction pathways of 2-chlorophenol and? OH were different under different pH values: the hydroxyl adducts were formed under neutral conditions and the rate constant of formation was 8.3 × 109dm3 mol-1? S-1 Under the acidic conditions, 2-chlorophenoxy is mainly generated by the electron transfer, and there are both the dehydration and dehydroxylation of hydroxyl adducts. • N3 and 2-chlorophenol undergoes a single electron oxidation to form 2-chlorophenoxy. ? H and 2 - chlorophenol addition reaction of cyclohexadiene-based hydrogen adduct, the rate constant of 2.5 × 109dm3? Mol-1? S-1. The electron-transfer of eaq with 2-chlorophenol leads to the formation of hydroxyphenyl and chloride ions. Under basic conditions (pH = 11) and under neutral conditions, the rate-constants are 3.5 × 108 dm3 mol-1 s-1 and 2.2 × 109 dm3? Mol-1? S-1. The results will help people to understand the nature of chlorophenol degradation, which provides a theoretical basis for the degradation of these compounds.