• 研究使用平台：NMT重金属创新科研平台
• 期刊：Environmental Pollution
• 主题：NMT验证稻田生物膜大量吸附Cd降低水稻Cd积累
• 标题：Paddy periphyton reduced cadmium accumulation in rice (Oryza sativa) by removing and immobilizing cadmium from the water–soil interface
• 影响因子：5.714
• 检测指标：Cd2+流速
• 检测样品：水稻附生植物
• Cd2+流实验处理方法：
  水稻幼苗在Cd0+P（附生植物），Cd5（5mg Kg-1的土壤Cd含量）+P和Cd50（50mg Kg-1的土壤Cd含量）+P处理60天后，取水稻附生植物进行测试。
• Cd2+流实验测试液成份：
  50 μM CdCl2, 0.1 mM KCl, 0.3 mM MES, and 0.1% sucrose, pH 6.0
• 作者：中国科学院南京土壤研究所刘俊琢、陆海鹰

中文摘要（谷歌机翻）

旱生植物在湿地的重金属转移中起着重要作用，但它对稻田中镉（Cd）生物利用度的贡献仍未得到充分探索。

这项研究的主要目的是研究水生植物对稻田镉行为的影响。围生植物显着降低了稻田水中Cd的浓度。

非侵入性微测试技术分析表明，附生植物可以从水中吸收Cd，最大Cd2+流入速率为394 pmol cm-2·s-1，而附生植物的入侵显着增加了土壤Cd的浓度。

然而，由于土壤pH升高和周生植物引起的土壤氧化还原电势（Eh）降低，土壤镉的生物利用度显着下降。在附生植物中，更多的Cd被吸附并固定在土壤中的有机物，碳酸盐，铁和锰的氧化物上。因此，水稻中的镉含量显着下降。

这些发现为深入了解附生植物在稻田中的Cd生物地球化学提供了可能，并为减少水稻中Cd的积累提供了新的策略。

Figure 3 Changes in net flux of Cd of periphyton over times (a) and the mean net influx of periphyton (b) under different treatments. Cd0+P, Cd5+P, and Cd50+P represent the periphyton treatment of Cd added at soil Cd content of 0 mg Kg-1, 5 mg Kg-1, and 50 mg Kg-1 respectively. Different letters within same column indicate significant difference among different treatments at P < 0.05, while same letters represent no significant difference.

英文摘要

Periphyton plays a significant role in heavy metal transfer in wetlands, but its contribution to cadmium (Cd) bioavailability in paddy fields remains largely unexplored.

The main aim of this study was to investigate the effect of periphyton on Cd behavior in paddy fields. Periphyton significantly decreased Cd concentrations in paddy waters.

Non-invasive micro-test technology analyses indicated that periphyton can absorb Cd from water with a maximum Cd2+ influx rate of 394 pmol cm−2 s−1 and periphyton intrusion significantly increased soil Cd concentrations.

However, soil Cd bioavailability declined significantly due to soil pH increase and soil redox potential (Eh) decrease induced by periphyton. With periphyton, more Cd was adsorbed and immobilized on organic matter, carbonates, and iron and manganese oxides in soil. Consequently, Cd content in rice decreased significantly.

These findings give insights into Cd biogeochemistry in paddy fields with periphyton, and may provide a novel strategy for reducing Cd accumulation in rice.

文章链接：

https://doi.org/10.1016/j.envpol.2020.114103