Cd pollution in arable soils has posed serious threats to food safety and human health. Mn oxides and Mn oxide-based materials have been widely applied to the removal of heavy metals for their high adsorption capacity, especially in water treatment. However, the performance and stability of Mn oxide-based materials and the underlying mechanism of Cd immobilization in upland soils remain unclear. Here, zeolite-supported Mn oxides were used as amendment to investigate their impact on the availability of soil Cd in wheat pot experiments. The decrease in soil available Cd content (by 44.3%) and increase in soil available Mn content (by 61.9%) significantly inhibited Cd accumulation in wheat plant tissues under the application of zeolite-supported Mn oxides. The exchangeable Cd was transformed to more stable fractionation of Fe-Mn oxide bound Cd, and the maximum decrease of Cd content in wheat grains, straw and roots reached 65.0%, 11.7% and 55.3%, respectively. Besides, zeolite-supported Mn oxides exhibited high chemical stability and stable Cd immobilization performance in two successive years of wheat pot experiments. These findings improve our understanding of Mn oxide-based materials for soil remediation and indicate that zeolite-supported Mn oxides have great potential for the remediation of Cd-contaminated alkaline upland soils.

耕地土壤中的镉污染已对食品安全和人类健康构成严重威胁。锰氧化物和锰氧化物基材料因其高吸附能力而被广泛应用于去除重金属，特别是在水处理中。然而，Mn氧化物基材料的性能和稳定性以及Cd在旱地土壤中的固定机制仍不清楚。在这里，沸石负载的 Mn 氧化物被用作改良剂，以研究它们对小麦盆栽实验中土壤 Cd 有效性的影响。在沸石负载的锰氧化物的应用下，土壤有效镉含量的降低（44.3%）和土壤有效锰含量的增加（61.9%）显着抑制了小麦植物组织中镉的积累。可交换的 Cd 转化为更稳定的 Fe-Mn 氧化物结合 Cd 的分馏，小麦籽粒、秸秆和根中Cd含量的最大降幅分别达到65.0%、11.7%和55.3%。此外，沸石负载的锰氧化物在连续两年的小麦盆栽实验中表现出较高的化学稳定性和稳定的 Cd 固定性能。这些发现提高了我们对基于 Mn 氧化物的土壤修复材料的理解，并表明沸石负载的 Mn 氧化物在修复受 Cd 污染的碱性高地土壤方面具有巨大潜力。