Highly efficient amendments for controlling arsenic (As) pollution in soils are imperative to improve soil quality and enhance food production. In the present study, corn stalk biochar was functionalized with three kinds of layered double hydroxides (i.e., Mg–Al-LDH, Zn–Al-LDH, and Cu–Al-LDH) using a simple co-precipitation method. The synthesized LDH biochar composites (LDH@BCs) exhibited better adsorption capacity and affinity for As due to their enhanced anion exchange capacity and reactive surface hydroxyl groups identified by XRD, FTIR and XPS. Arsenic (As) bioavailability and leaching characteristics of spiked red and calcareous soils (150 mg As/kg) amended with or without LDH@BCs were investigated using soil column. The Zn–Al-LDH@BC decreased the As (V) migration and increased pak choi (Brassica chinensis L.) growth in both red and calcareous soil. These results indicated that LDH modified biochar is an effective way to overcome the shortfalls of unmodified biochar in mitigating the As contamination and provide a basis for further exploring the potential of biochar-based soil amendments for environmental remediation.

必须有效地控制土壤中砷污染，以改善土壤质量和提高粮食产量。在本研究中，玉米秸秆生物炭通过一种简单的共沉淀方法，通过三种层状双氢氧化物（即Mg-Al-LDH，Zn-Al-LDH和Cu-Al-LDH）进行功能化。合成的LDH生物炭复合材料（LDH @ BCs）具有更好的吸附能力和对As的亲和力，这是因为它们具有增强的阴离子交换能力和通过XRD，FTIR和XPS鉴定的反应性表面羟基。使用土壤柱研究了添加或不添加LDH @ BCs的红色和钙质加标土壤（150 mg As / kg）的砷（As）生物利用度和浸出特性。Zn-Al-LDH @ BC减少了As（V）迁移并增加了白菜（小白菜在红色和钙质土壤中均生长。这些结果表明，LDH改性生物炭是克服未改性生物炭减少As污染的有效方法，并为进一步探索基于生物炭的土壤改良剂用于环境修复的潜力提供了基础。