Metal (loid) soil pollution is an important issue worldwide that requires the use of remediation, using plants for instance. However, for plants to grow and be efficient, soil fertility must be improved and metal(loid) toxicity reduced. In such an assisted remediation context, biochar has been shown to improve soil conditions and thus plant growth. However, few field studies over long time periods have been conducted to assess biochar impact on metal(loid)s in soil. The objectives of this study were to evaluate the efficiency of a biochar amendment, under field conditions, to improve soil physico-chemical properties and immobilize metal(loid)s and to study the possible mechanisms of such metal(loid) immobilization. For this, biochar was applied to a former mine technosol highly contaminated with As and Pb. Soil samples were taken prior to biochar amendment, on the day of biochar application and 6 months after biochar incorporation. The analyses showed that biochar increased soil pH, organic matter content and nutrient availability, and immobilized Pb. Such results were observed directly after biochar application and were still observed after 6 months, whereas As was first mobilized then immobilized. Finally, the analysis of the samples using scanning electron microscopy coupled with energy dispersive spectroscopy showed that Pb was immobilized, at least partly on the biochar surface, as PbCO₃.

金属（类）土壤污染是世界范围内的重要问题，需要进行补救，例如使用植物。但是，为了使植物生长并高效生长，必须提高土壤肥力并降低金属（金属）毒性。在这种辅助修复的背景下，生物炭已被证明可以改善土壤状况，从而改善植物生长。然而，很少进行长时间的现场研究来评估生物炭对土壤中金属（金属）的影响。这项研究的目的是在田间条件下评估生物炭改良剂的效率，以改善土壤的理化性质并固定化金属（胶体），并研究这种金属化（胶体）固定化的可能机理。为此，将生物炭应用于曾被砷和铅高度污染的前矿山甲酚。在生物炭改良之前，生物炭施用当天和生物炭掺入后的6个月内取样土壤样品。分析表明，生物炭增加了土壤的pH值，有机质含量和养分利用率，并固定了Pb。这些结果在施用生物炭后直接观察到，并且在6个月后仍然观察到，而先将A转移然后固定。最后，使用扫描电子显微镜和能量色散光谱法对样品进行分析表明，Pb至少部分固定在生物炭表面，如PbCO 这些结果在施用生物炭后直接观察到，并且在6个月后仍然观察到，而先将A转移然后固定。最后，使用扫描电子显微镜和能量色散光谱法对样品进行分析表明，Pb至少部分固定在生物炭表面，如PbCO 这些结果在施用生物炭后直接观察到，并且在6个月后仍然观察到，而先将A转移然后固定。最后，使用扫描电子显微镜和能量色散光谱法对样品进行分析表明，Pb至少部分固定在生物炭表面，如PbCO₃。