不同铁氧化物对小麦幼苗镉积累的影响

小麦富镉(Cd)问题受到广泛关注,铁氧化物具备降镉潜力.通过盆栽小麦幼苗实验,分析了三氧化二铁(Fe2O3)、氢氧化铁[Fe(OH)3[及拜耳法赤泥(B-RM)3种铁氧化物的降镉能力.结果显示3种铁氧化物中,Fe(OH)3可显著降低小麦幼苗茎叶Cd含量,与对照相比降幅为16.3％～27.7％,投加量为0.5％时降Cd效...

Effects of different iron oxides on cadmium accumulation in wheat seedlings

Cadmium (Cd) accumulation in wheat grain is of great concern. The iron-oxides showed the potential to decrease the Cd uptake by wheat. In this study, the greenhouse experiments were conducted to investigate the effects of iron oxides, namely ferric oxide (Fe₂O₃), ferric hydroxide[Fe(OH)₃] and red mud from Bayer process (B-RM) on suppressing Cd accumulation in wheat seedlings. Among the three amendments, Fe(OH)₃ showed effective results in reducing Cd accumulation in the shoot of wheat seedlings, with the average Cd concentration was decreased by 16.3%~27.7% as compared to the control. The minimum Cd concentration was observed at the treatment with Fe(OH)₃ at 0.5% dosage. The application of Fe(OH)₃ could reduce the accumulation of Cd from soil to root, and the transport of Cd from root to shoot, with the minimum plant uptake factor and translocation factor of Cd was observed at the treatment with Fe(OH)₃ above 10% dosage. The ratio of Fe, Cu and Zn to Cd in rhizosphere soil was the key factor affecting the accumulation of Cd in the shoot of wheat seedlings. When Fe/Cd, Cu/Cd and Zn/Cd was more than 25000, 50 and 100, respectively, significant and negative correlations were found between Cd concentration in the shoot of wheat seedlings and the ratio of Fe/Cd, Cu/Cd and Zn/Cd. The determination of the ratio between soil trace elements could help to identify the optimal dosages of amendments in the field application for minimizing grain Cd concentration.