Abstract: Oxidative degradation of methyl orange (MO) in aqueous solution by zero-valent iron-activated sodium peroxydisulfate (PDS) was investigated. The degradation process was based on generation of sulfate radicalsas powerful oxidizing species. The effects of dosages of PDS and Fe0，initial pH，temperature and initial concentration of MO on MO degradation were examined in batch experiments. The results demonstrated that MO could be degraded by Fe0/PDS reagent effectively. Under the condition with initial MO concentration 100 mg?L－1，PDS dosage 0.912 mmol?L－1，Fe0 dosage 0.16 g?L－1，pH 4.0，temperature 298 K，MO degradation in aqueous solution reached 80.2% within 2.5 h. At the same time，the kinetics of Fe0/PDS system oxidation of MO was investigated, and the results demonstrated that degradation of MO occurred in two stages, and the second stage of the reaction followed first-order kinetics behavior.

Key words: Key words：persulfate, Fe0, Methyl Orange, heterogeneous catalysis, kinetic, persulfate, Fe0, methyl orange, heterogeneous catalysis, kinetic

摘要： 采用零价铁（Fe0）活化过硫酸钠（PDS）的方式产生具有强氧化性的硫酸根自由基，以偶氮染料甲基橙（MO）为目标污染物，考察了硫酸根自由基对甲基橙的氧化降解行为。系统研究了PDS、Fe0投加量、体系初始pH值、反应温度以及染料初始浓度对反应的影响。结果表明：Fe0/PDS体系能有效地降解甲基橙，在MO初始浓度100 mg/L、PDS投加量为0.912 mmol/L、Fe0投加量0.16 g/L、初始pH值为4.0、温度为298 K的条件下，反应进行2.5 h MO去除率达到80.2%；同时还探索了Fe0/PDS体系降解MO的动力学过程，证实了MO的降解分为两个阶段，且第二阶段的氧化降解符合一级动力学反应。

关键词: 关键字：过硫酸盐, 零价铁, 甲基橙, 非均相催化, 动力学, 过硫酸盐, 零价铁, 甲基橙, 非均相催化, 动力学