Department of Civil & Environmental Engineering, Washington State University, Pullman, WA 99163-2910, United States.
Department of Civil & Environmental Engineering, Washington State University, Pullman, WA 99163-2910, United States.
Water Res. 2018 Apr 15;133:247-254. doi: 10.1016/j.watres.2018.01.050. Epub 2018 Feb 3.
Sodium persulfate has become the most popular oxidant source for the in situ chemical oxidation (ISCO) treatment of organic contaminants in the subsurface. The most common persulfate activators, iron chelates and base, are often ineffective in initiating the generation of reactive oxygen species in field applications. In this study, glucose was investigated as a persulfate activator in systems containing varying concentrations of sodium hydroxide using nitrobenzene as a hydroxyl radical probe and hexachloroethane as a reductant + nucleophile probe. Glucose activation of persulfate increased as a function of sodium hydroxide addition, but was still effective at circumneutral pH regimes. Use of central composite rotatable experimental designs showed that hydroxyl radical and reductant + nucleophile generation rates increased as a function of persulfate at near-neutral pH regimes. Glucose activation of persulfate has the advantages over other activation pathways of more options and flexibility for effective process chemistry and of minimizing or eliminating the mass of sodium hydroxide added to the subsurface. The results of this research can be applied in the field by first evaluating glucose activation compared to base and iron chelate activation of persulfate in laboratory treatability studies.
过硫酸钠已成为原位化学氧化（ISCO）处理地下有机污染物最受欢迎的氧化剂来源。最常见的过硫酸盐活化剂，如铁螯合物和碱，在现场应用中通常无法有效引发活性氧的生成。在这项研究中，使用硝基苯作为羟基自由基探针和六氯乙烷作为还原剂+亲核探针，研究了葡萄糖作为过硫酸盐在含有不同浓度氢氧化钠的系统中的活化剂。随着氢氧化钠的加入，过硫酸钠的葡萄糖活化作用增强，但在近中性 pH 条件下仍有效。使用中心复合旋转实验设计表明，在近中性 pH 条件下，随着过硫酸盐的增加，羟基自由基和还原剂+亲核物的生成速率也随之增加。过硫酸钠的葡萄糖活化作用具有比其他活化途径更多的优势，更灵活地进行有效的工艺化学，并最大程度地减少或消除向地下添加的氢氧化钠的质量。通过首先在实验室可处理性研究中评估过硫酸盐的葡萄糖活化与碱和铁螯合物活化的比较，可以将本研究的结果应用于现场。
