Here we addressed the remediation of a soil severely contaminated by Cu, Cd, Pb and Zn. In this regard, we tested the capacity of magnesite and biochar, inorganic and organic soil amendments, respectively, to reduce metal availability and improve soil properties. To this end, 1-kg pots containing the polluted soil were amended with either magnesite or biochar. Metal availability and soil properties were then measured at days 15 and 75. Also, to evaluate the impact of the two treatments on plant growth, we conducted experimental trials with Brassica juncea L. and compost addition. Both amendments, but particularly magnesite, markedly decreased metal availability. Soil properties were also enhanced, as reflected by increases in the cation exchangeable capacity. However, plant growth was inhibited by magnesite amendment. This observation could be attributable to an increase in soil pH and cation exchange capacity as well as a high Mg concentration. In contrast, biochar increased biomass production but decreased the quantity of metals recovered when the plants are harvested. In conclusion, on the basis of our results, we propose magnesite as a suitable approach for stabilizing contaminated soils (or even spoil heaps) where revegetation is not a priority. In contrast, although biochar has a lower, but still significant, capacity to immobilize metals, it can be used to restore natural soil properties and thus favor plant growth.

在这里，我们解决了被 Cu、Cd、Pb 和 Zn 严重污染的土壤的修复。在这方面，我们分别测试了菱镁矿和生物炭、无机和有机土壤改良剂在降低金属可用性和改善土壤特性方面的能力。为此，用菱镁矿或生物炭对装有污染土壤的 1 公斤花盆进行了改良。然后在第 15 天和第 75 天测量金属可用性和土壤特性。此外，为了评估两种处理对植物生长的影响，我们对芥菜进行了实验试验L. 和堆肥添加。两种修正，尤其是菱镁矿，都显着降低了金属的可用性。土壤性质也得到了增强，这反映在阳离子交换能力的增加上。然而，植物生长受到菱镁矿改良剂的抑制。这一观察结果可归因于土壤 pH 值和阳离子交换能力的增加以及高镁浓度。相比之下，生物炭增加了生物质产量，但减少了收获植物时回收的金属量。总之，根据我们的结果，我们建议将菱镁矿作为稳定受污染土壤（甚至弃土堆）的合适方法，在这些土壤中，重新植被不是优先考虑的事项。相比之下，虽然 biochar 具有较低但仍然显着的金属固定能力，