Chemical amendments have been used to remediate soils contaminated with heavy metals. However, there is little understanding on the impacts of these amendments on the physiological and biochemical functions of plants and soil. This study used in situ microcosm experiment to understand the effect of chemical amendments on antioxidant and soil enzyme activity in plant and soil with respect to heavy metal reduction. Three chemical amendments—acid mine drainage sludge (AMDS), limestone (LS), and steel slag (SS)—were applied to soil at 3, 5, and 10% mixing ratios, and lettuce (Lactuca sativa) was cultivated in that soil for 30 days. The results showed that bioavailable Cd and Pb in soil was reduced by 9.8–40.5% and 4.2–92.5%, respectively. The most efficient amendment for heavy metal reduction was AMDS. The uptake of Cd and Pb also decreased by 0.5–66.1 and 21.6–79.5%, respectively, depending on the amendment type and application ratio. The activity of three antioxidants—catalase (CAT), ascorbate peroxidase (APX), and glutathione reductase (GR)—was generally higher than the control with no amendments. This result indicated that there was minimal inhibition of antioxidant activity due to the reduction of heavy metal uptake. Also, no significant difference was observed in chemical amendments applied soil compared to control in terms of soil enzyme activity. However, correlation analysis between heavy metal concentration in soil and two soil enzyme activities showed that significantly negative correlation (p < 0.01) was observed between bioavailable Pb in soil and acid-phosphatase activity. This result might indicate that impact of bioavailable Pb was much higher than Cd in terms of inhibition of soil enzyme activity. Overall, the application of chemical amendments to heavy metal polluted had a positive effect on plant physiological function and soil enzyme activity with a reduction in bioavailable heavy metals in soil and plants.

中文翻译：

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化学改良剂对土壤中重金属的修复及其对生菜（Lactuca sativa）中抗氧化酶和土壤酶活性的影响。

化学改良剂已被用来修复被重金属污染的土壤。但是，对这些修订对植物和土壤的生理和生化功能的影响知之甚少。这项研究使用原位缩影实验来了解化学修饰对植物和土壤中抗氧化剂和土壤酶活性的影响，包括减少重金属。在土壤中以3％，5％和10％的比例施用了三种化学改良剂-酸性矿山排水污泥（AMDS），石灰石（LS）和钢渣（SS），并在该土壤中种植了生菜（Lactuca sativa） 30天。结果表明，土壤中可利用的Cd和Pb分别减少了9.8–40.5％和4.2–92.5％。减少重金属最有效的方法是AMDS。镉和铅的吸收也降低了0.5-66。分别为1和21.6–79.5％，具体取决于修订类型和应用比例。三种抗氧化剂（过氧化氢酶（CAT），抗坏血酸过氧化物酶（APX）和谷胱甘肽还原酶（GR））的活性通常高于未作任何修饰的对照。该结果表明，由于减少了重金属的吸收，对抗氧化剂活性的抑制作用最小。此外，就土壤酶活性而言，与对照相比，在施用化学改良剂的土壤中未观察到显着差异。然而，土壤中重金属浓度与两种土壤酶活性之间的相关性分析表明，土壤中可生物利用的铅与酸性磷酸酶活性之间存在显着的负相关性（p <0.01）。该结果可能表明，就土壤酶活性的抑制而言，可生物利用的铅的影响远大于镉。总体而言，对污染的重金属应用化学改良剂对植物的生理功能和土壤酶活性具有积极的影响，同时减少了土壤和植物中可生物利用的重金属。