Lin Qi, Chen YingXu, Wang ZhaoWei, Wang YuanPeng
Department of Environmental Engineering, Zhejiang University, Huajiachi Campus, 268 Kaixuan Road, Hangzhou 310029, People's Republic of China.
Chemosphere. 2004 Dec;57(10):1439-47. doi: 10.1016/j.chemosphere.2004.08.070.
Hydrogen peroxide was widely selected as the chemical oxidant in chemical remediation or as the donor of oxygen in in situ aerobic bioremediation of organic pollutants. In this paper, hydrogen peroxide pretreatment and plant system was done to examine its possibility to remediate the heavy metal contaminated soil or heavy metal-organic combined contaminated soil. Heavy metal contaminated soil was collected from the heavily industrialized area, in Fuyang county, Zhejiang province, China. And heavy metal-organic combined contaminated soil was prepared from the same contaminated soil by spiking 100 microg g(-1) 2,4-dichlorophenol (2,4-DCP). Results showed that H2O2 could improve the dissipation of 2,4-DCP and enhance the availability of Cu and Zn in soil. The greatly increased DOC (dissolved organic carbon) in the oxidation process was probably the main reason for the greatly increased water soluble Cu in higher pH condition. Water soluble Zn, however, easily rebound to soil components with the time being and had no positive relation with dissolved organic carbon. Planting with ryegrass influenced the behavior of pollutants in soil. It was observed that the dissipation of 2,4-DCP could be enhanced by the presence of plant roots and the availability of Cu and Zn in the planted soil was changed due to the mobilization and rebound mechanisms in the rhizosphere. Co-contamination of 2,4-DCP caused the greater availability of Cu and Zn in H2O2 pretreatment. But with the ryegrass planting, it was easier to rebound to the less available phase in the rhizosphere. Both Cu and Zn concentration in shoots increased with the H2O2 treatment. Therefore our results suggested that H2O2 pretreatment was probably a promising way for promoting the dissipation of persistent organic pollutants and enhancing the solubility of Cu and Zn in soil. A combination of H2O2 pretreatment and suitable plant might be an efficient alternative for remedying heavy metal or heavy metal-organic contaminated soil.
过氧化氢在化学修复中被广泛用作化学氧化剂，或在有机污染物的原位好氧生物修复中作为氧的供体。本文进行了过氧化氢预处理和植物系统实验，以研究其修复重金属污染土壤或重金属 - 有机复合污染土壤的可能性。重金属污染土壤取自中国浙江省富阳县工业化程度较高的地区。重金属 - 有机复合污染土壤则是在相同污染土壤中添加100 μg g(-1) 的2,4 - 二氯苯酚（2,4 - DCP）制备而成。结果表明，H₂O₂ 能促进2,4 - DCP的降解，并提高土壤中铜和锌的有效性。氧化过程中大幅增加的溶解有机碳（DOC）可能是高pH条件下水溶性铜大幅增加的主要原因。然而，水溶性锌会随时间容易重新吸附到土壤组分中，与溶解有机碳没有正相关关系。种植黑麦草会影响土壤中污染物的行为。观察到植物根系的存在可促进2,4 - DCP的降解，且种植土壤中铜和锌的有效性因根际的活化和重新吸附机制而发生变化。2,4 - DCP的共污染导致H₂O₂ 预处理后铜和锌的有效性更高。但随着黑麦草的种植，它们在根际更容易重新吸附到有效性较低的形态。地上部分铜和锌的浓度均随H₂O₂ 处理而增加。因此，我们的结果表明，H₂O₂ 预处理可能是促进持久性有机污染物降解以及提高土壤中铜和锌溶解度的一种有前景的方法。H₂O₂ 预处理与合适植物的组合可能是修复重金属或重金属 - 有机污染土壤的有效替代方法。
