【摘要】 采用反应平衡法并结合盆栽试验研究了H2O2对重金属污染土壤的活化作用及对后续植物修复中重金属根际效应的影响.研究表明污染土壤施入H2O2后,水溶性总铜、总锌均较对照有显著的增加,说明H2O2对污染土壤重金属的活化有很强的效果.Fe2+加入使重金属活性降低,施加量越高,土壤溶液水溶性铜锌含量越低.经H2O2预处理的土壤栽种黑麦草后将进一步溶出铜锌,其中,对黑麦草根际水溶态铜含量的影响比锌显著.H2O2预处理并不改变污染土壤重金属的主要存在形态,但经H2O2预处理的土壤栽种黑麦草后,水溶态+交换态铜含量增幅较大说明经H2O2预处理重金属在土壤中的结合强度可能减弱,易于受根际的影响而活化.H2O2预处理土壤栽种黑麦草后,弱专性吸附态铜锌均明显增加、残渣态铜锌减少.即提取试验和盆栽试验结果均表明H2O2预处理对提高土壤中重金属的生物有效性、促进植株吸收重金属效果显著.更多还原

【Abstract】 Effect of hydrogen peroxide on the solubilization and rhizospheric dynamics of heavy metals in contaminated soils was studied. The results showed that water soluble Cu and Zn increased significantly after being treated with H₂O₂, which indicatd that H₂O₂ is a safe and efficient reagent to be used in enhancing the availability of heavy metals in soil. Addition of Fe²+ decreased the water soluble Cu and Zn. The more was Fe^<sup>2+ added, the less was the water soluble Cu and Zn. Planting ryegrass in the contaminated soil pretreated with hydrogen peroxide led to further increase of water soluble Cu and Zn present. And it was more effective of hydrogen peroxide in releasing Cu into soil solution than Zn. The fractionation of heavy metals was similarly distributed among soils. But hydrogen peroxide pretreatment distinctively increased the copper in the soluble plus exchangeable fraction （SE-Cu） in the planted soil, which indicated that binding strength of heavy metals in soil was weakened after the soil was treated with hydrogen peroxide, and was liable to be mobilized by the influence of the rhizosphere of ryegrass. Besides, the increase of copper and zinc levels in the weekly and specifically adsorbed fraction （WSA-Cu, WSA-Zn） and decrease of residual Cu and Zn levels were also observed in planted soil after hydrogen peroxide treatment. In conclusion, hydrogen peroxide pretreatment might be an efficient way for enhancing the bioavailability of heavy metals in soil and promoting the absorption of heavy metals by plants.更多还原