Heavy metal pollution in soils is currently a critical environmental issue. Soil amendments can reduce the availability of contaminants and retard their offsite movement by water. A study was conducted to reduce the water solubility and leachability of heavy metals (HM) (cadmium (Cd), lead (Pb), nickel (Ni), chromium (Cr), and copper (Cu)) from polluted soil using various ground natural materials, namely slate, gypsum, lime, shale, and clay. Polluted soil samples were collected from Hattar Industrial areas of Haripur, Pakistan, noted for metal contamination. Mineral amendments were applied to those soil samples at the rate of 2.5 and 5% along with the control (no amendment). Results showed that the amendment material apparently reduced the solubilization of heavy metals (p < 0.05). The heavy metal concentrations in the soil were in the order Pb > Cr > Ni > Cd > Cu. After 10 days of incubation, the Cd concentration was reduced on average by the mineral amendment, but the reduction varied in the order slate > clay > lime > shale > gypsum. These materials were also differed for Pb (at p < 0.05), the reduction was in the order shale > lime > clay > slate > gypsum, and for Ni as the order was slate > clay > gypsum > shale > lime. Chromium and Cu were reduced similarly. Reduction in the metal solubility was highly related to the application rate of material. The leachability of trace elements from soil was also a function of amendment and the material differed for heavy metals during the leaching process. This research indicates that mineral material may act as an adsorbent for the metal contaminant and thus reduces their leachability from soils. Moreover, the availability of heavy metals in contaminated soils can be reduced by using mineral amendment.

土壤中的重金属污染目前是一个关键的环境问题。土壤改良剂会减少污染物的可利用性，并阻止污染物在水外的移动。进行了一项研究，以减少污染土壤中重金属（HM）（镉（Cd），铅（Pb），镍（Ni），铬（Cr）和铜（Cu））的水溶性和浸出度，天然材料，即板岩，石膏，石灰，页岩和粘土。从巴基斯坦哈里普尔的哈塔尔工业区收集了污染的土壤样品，发现有金属污染。将矿物质改良剂与对照一起以2.5和5％的比例应用于这些土壤样品（无改良剂）。结果表明，改性材料明显减少了重金属的溶解（p<0.05）。土壤中的重金属浓度依次为Pb> Cr> Ni> Cd> Cu。孵育10天后，平均Cd浓度通过矿物改良剂降低，但降低程度依次为板岩>粘土>石灰>页岩>石膏。这些物质的铅含量也有所不同（在p<0.05），还原度依次为页岩>石灰>粘土>板岩>石膏，而对于Ni而言，还原度依次为板岩>粘土>石膏>页岩>石灰。铬和铜的还原相似。金属溶解度的降低与材料的施用率高度相关。土壤中微量元素的浸出性也是修正的函数，浸出过程中重金属的物质也有所不同。这项研究表明，矿物材料可能充当金属污染物的吸附剂，从而降低了它们从土壤中的浸出能力。此外，通过使用矿物改良剂可以减少污染土壤中重金属的可用性。