Abstract:

A multi-component catalytic oxidation system was developed for organic contaminated sites soil in this study. In the system, sodium persulfate and hydrogen peroxide were used as the oxidant, Fe²⁺and Cu²⁺ were used as transition metal catalyst, meanwhile, ascorbic acid was used as the complexing agent, forming the homogeneous liquid catalytic oxidation repair reagent. The developed remediation regent was performed in UV light treatment under 50℃ to constitute a three-component activation system including UV light, transition metal ion and thermal activation. The addition of Cu²⁺ effectively promoted the reduction from Fe³⁺ to Fe²⁺. And the addition of ascorbic acid effectively regulate the continuous activation of Fe²⁺. In this oxidation system, the degradation of organic pollutants mainly relies on active free radicals $\mathrm{S}{\mathrm{O}}_{\mathrm{4}}^{·-}$ and HO·. The developed technology was applied to the soil remediation of high-concentration organic contaminated plots. After 30 days of remediation, the removal rates of OPs, PAHs, and BTEX in the soil were 85.0%, 60.5%, and 73.0%, respectively. The efficient removal of organic pollutants in the soil was achieved, providing the basis for the safety development of complex contaminated sites and the improvement of land resources in our country.

Key words: organic contaminated site soil, oxidation, multi-component activation, remediation, free radicals

摘要：

本文针对有机污染土壤，开发了一种多元催化氧化技术。以过硫酸钠和双氧水作为氧化剂，Fe²⁺和Cu²⁺作为过渡金属活化剂，同时以抗坏血酸作为络合剂，形成均相液体修复药剂。在50℃的反应条件下耦合紫外光照处理，形成过渡金属离子、热、光三元活化体系。其中Cu²⁺的添加有效促进了Fe³⁺向Fe²⁺的还原过程，抗坏血酸的加入有效调节Fe²⁺的持续活化作用。本氧化体系中主要依靠活性自由基$\mathrm{S}{\mathrm{O}}_{\mathrm{4}}^{·-}$和HO·对有机污染物进行降解。将开发技术应用于高浓度有机污染地块土壤修复中，经30 d修复后土壤中OPs、PAHs、BTEX去除率分别为85.0%、60.5%和73.0%。实现了土壤中有机污染物的高效去除，为我国复杂污染场地安全开发与土地资源价值提升提供一定依据。

关键词: 有机污染场地土壤, 氧化, 多元活化, 修复, 自由基