Guizhou University, Guiyang 550025, China.
Guizhou Chuyang Ecological Environmental Protection Technology Co., Ltd., Guiyang 550025, China.
Int J Environ Res Public Health. 2022 Sep 17;19(18):11736. doi: 10.3390/ijerph191811736.
The in situ chemical immobilization method reduces the activity of heavy metals in soil by adding chemical amendments. It is widely used in farmland soil with moderate and mild heavy metal pollution due to its high efficiency and economy. However, the effects of different materials depend heavily on environmental factors such as soil texture, properties, and pollution levels. Under the influence of lead-zinc ore smelting and soil acidification, Cd is enriched and highly activated in the soils of northwestern Guizhou, China. Potato is an important economic crop in this region, and its absorption of Cd depends on the availability of Cd in the soil and the distribution of Cd within the plant. In this study, pot experiments were used to compare the effects of lime (LM), apatite (AP), calcite (CA), sepiolite (SP), bentonite (BN), and biochar (BC) on Cd accumulation in potatoes. The results showed that the application of LM (0.4%), AP (1.4%), and CA (0.4%) had a positive effect on soil pH and cations, and that they effectively reduced the availability of Cd in the soil. In contrast, the application of SP, BN, and BC had no significant effect on the soil properties and Cd availability. LM, AP, and CA treatment strongly reduced Cd accumulation in the potato tubers by controlling the total 'flux' of Cd into the potato plants. In contrast, the application of SP and BN promoted the migration of Cd from the root to the shoot, while the effect of BC varied by potato genotype. Overall, calcareous materials (LM, CA, and AP) were more applicable in the remediation of Cd-contaminated soils in the study area.
原位化学固定法通过添加化学改良剂来降低土壤中重金属的活性。由于其高效和经济，该方法广泛应用于中轻度重金属污染的农田土壤。然而，不同材料的效果在很大程度上取决于土壤质地、特性和污染水平等环境因素。在中国贵州西北部，由于受到铅锌矿冶炼和土壤酸化的影响，土壤中 Cd 得到了富集和高度活化。马铃薯是该地区的一种重要经济作物，其对 Cd 的吸收取决于土壤中 Cd 的有效性和 Cd 在植物体内的分布。在本研究中，采用盆栽试验比较了石灰（LM）、磷灰石（AP）、方解石（CA）、海泡石（SP）、膨润土（BN）和生物炭（BC）对马铃薯中 Cd 积累的影响。结果表明，LM（0.4%）、AP（1.4%）和 CA（0.4%）的应用对土壤 pH 值和阳离子有积极影响，有效地降低了土壤中 Cd 的有效性。相比之下，SP、BN 和 BC 的应用对土壤性质和 Cd 的有效性没有显著影响。LM、AP 和 CA 处理通过控制 Cd 向马铃薯植株总“通量”的方式，强烈降低了马铃薯块茎中 Cd 的积累。相比之下，SP 和 BN 的应用促进了 Cd 从根部向地上部的迁移，而 BC 的效果因马铃薯基因型而异。总体而言，在研究区域的 Cd 污染土壤修复中，钙质材料（LM、CA 和 AP）更适用。
