Department of Civil and Environmental Engineering, Washington State University, Pullman, WA 99164-2910, USA.
J Contam Hydrol. 2010 Jun 25;115(1-4):34-45. doi: 10.1016/j.jconhyd.2010.04.002. Epub 2010 Apr 14.
Persulfate dynamics in the presence of subsurface minerals was investigated as a basis for understanding persulfate activation for in situ chemical oxidation (ISCO). The mineral-mediated decomposition of persulfate and generation of oxidants and reductants was investigated with four iron and manganese oxides and two clay minerals at both low pH (<7) and high pH (>12). The manganese oxide birnessite was the most effective initiator of persulfate for degrading the oxidant probe nitrobenzene, indicating that oxidants are generated at both low and high pH regimes. The iron oxide goethite was the most effective mineral for degrading the reductant probe hexachloroethane. A natural soil and two soil fractions were used to confirm persulfate activation by synthetic minerals. The soil and soil fractions did not effectively promote the generation of oxidants or reductants. However, soil organic matter was found to promote reductant generation at high pH. The results of this research demonstrate that synthetic iron and manganese oxides can activate persulfate to generate reductants and oxidants; however, iron and manganese oxides in the natural soil studied do not show the same reactivity, most likely due to the lower masses of the metal oxides in the soil relative to the masses studied in isolated mineral systems.
研究了亚表面矿物存在下过硫酸盐的动力学，以此为基础了解过硫酸盐在原位化学氧化（ISCO）中的活化作用。在低 pH（<7）和高 pH（>12）条件下，用四种铁和锰氧化物以及两种粘土矿物研究了矿物介导的过硫酸盐分解以及氧化剂和还原剂的生成。氧化锰水钠锰矿是过硫酸盐降解氧化剂探针硝基苯的最有效引发剂，这表明在低 pH 和高 pH 条件下都生成了氧化剂。氧化铁针铁矿是降解还原剂探针六氯乙烷的最有效矿物。天然土壤和两种土壤级分用于证实合成矿物对过硫酸盐的活化作用。土壤和土壤级分不能有效地促进氧化剂或还原剂的生成。然而，发现土壤有机质在高 pH 下促进还原剂的生成。本研究结果表明，合成铁和锰氧化物可以活化过硫酸盐以生成还原剂和氧化剂；然而，在所研究的天然土壤中，铁和锰氧化物并没有表现出相同的反应活性，这很可能是由于土壤中金属氧化物的质量相对低于在孤立矿物系统中研究的质量。
