Fe-modified biochar has been shown to have high sorption ability for cadmium (Cd), while Cd immobilization effects of Fe-modified biochars with Si-rich and S-rich feedstocks have been rarely addressed. To explore the effects of Fe-modified Si-rich and S-rich biochars on Cd translocation in the soil-rice system, a pot experiment was carried out with an acidic Cd-contaminated sandy loam paddy from central South China and a late season rice cultivate during July to November 2018. Rice straw and rice husk were chosen as Si-rich feedstocks, and rape straw was applied as S-rich feedstock, these feedstocks were further collected and pyrolyzed at 450 °C. Pristine and Fe-impregnated rice straw (BRS/BRS-Fe), rice husk (BRH/BRH-Fe) and rape straw (BRE/BRE-Fe) biochars were applied at 0 and 10 t/ha, respectively. The reductions in Cd concentrations in rice grains were 23.8%, 22.3% and 46.1% with treatments of BRE, BRS and BRH, respectively, compared to the control. Compared to other pristine biochars, BRH is more effective in Cd remediation in paddy soil. For Fe-modified biochars, BRE-Fe achieved the highest reductions in Cd concentrations in rice grains with 46.7% and 30.1%, compared with the control and BRE, respectively. BRE-Fe decreased Cd remobilization from leaves to grains. Only BRE-Fe enhanced the formation and Cd sorption capacity of iron plaque. BRS-Fe and BRH-Fe enhanced Fe content in rice plants, which might induce the reduction in iron plaque formation. Fe and S-contained complexes contents increased in the contaminated pristine biochar particles, but reduced in the contaminated BRE-Fe particles. Therefore, Fe modification could not enhance Cd immobilization effect of Si-rich biochar, while Fe modified S-rich biochar has promising potential for Cd remediation with enhancement in iron plaque formation and Cd fixation in rice leaves.

铁改性生物炭已被证明对镉 (Cd) 具有高吸附能力，而含富硅和富硫原料的铁改性生物炭对 Cd 的固定作用很少被提及。为探讨铁修饰富硅和富硫生物炭对土壤-水稻系统中镉易位的影响，以华南中部受镉污染的酸性砂壤土和晚稻进行盆栽试验。 2018 年 7 月至 11 月栽培。选择稻草和稻壳作为富硅原料，油菜秸秆作为富硫原料，这些原料被进一步收集并在 450°C 下热解。分别以 0 吨/公顷和 10 吨/公顷的量施用原始和铁浸渍稻草 (BRS/BRS-Fe)、稻壳 (BRH/BRH-Fe) 和油菜秸秆 (BRE/BRE-Fe) 生物炭。与对照相比，BRE、BRS 和 BRH 处理的水稻籽粒中 Cd 浓度分别降低了 23.8%、22.3% 和 46.1%。与其他原始生物炭相比，BRH 对水稻土中的 Cd 修复更有效。对于 Fe 改性的生物炭，与对照和 BRE 相比，BRE-Fe 实现了米粒中 Cd 浓度的最高降低，分别为 46.7% 和 30.1%。BRE-Fe 减少了从叶子到谷物的 Cd 再动员。只有 BRE-Fe 增强了铁斑块的形成和 Cd 吸附能力。BRS-Fe 和 BRH-Fe 提高了水稻植株中的 Fe 含量，这可能会导致铁斑形成的减少。受污染的原始生物炭颗粒中铁和含硫复合物含量增加，但在受污染的 BRE-Fe 颗粒中降低。所以，