赤泥基纳米零价铁对多金属污染土壤修复效果

为实现重金属复合污染（Pb、Zn、Cu和Cd）土壤同步修复，构建土壤-小白菜体系，探究赤泥（RM）、纳米赤泥（RMn）以及纳米赤泥负载纳米零价铁（RMn-nZVI）这3种不同赤泥基钝化剂对Pb、Zn、Cu和Cd复合污染土壤的修复效果与机制，并考察土壤中Pb、Zn、Cu和Cd形态分布对小白菜积累Pb、Zn、Cu和Cd的控制作用.结果显示，3种钝化剂施用可显著提高土壤pH，降低土壤酸可提取态（F1）Pb、Zn、Cu和Cd含量，增加残渣态（F4）含量，最终钝化效果表现为：RMn-nZVI>RMn>RM.此外，3种钝化剂显著降低了小白菜可食用部分Pb、Zn、Cu和Cd的积累，其中RMn-nZVI处理下降低程度最高，Pb、Zn、Cu和Cd含量分别下降35.11%、45.05%、69.52%和59.63%.结果表明，纳米赤泥负载纳米零价铁新型钝化材料在重金属复合污染土壤修复领域具有一定的应用潜力.

Effect of Red Mud-based Nano Zero-valent Iron on Remediation of Polymetallic Contaminated Soil

In order to realize the simultaneous remediation of heavy metal composite-contaminated （Pb, Zn, Cu, and Cd） soils, a soil-pakchoi system was established to study the effect and mechanism of three passivators, red mud （RM）, nano red mud （RMn）, and nano red mud loaded with nano zero-valent iron （RMn-nZVI）, on the remediation of Pb, Zn, Cu, and Cd composite-contaminated soils and to explore the effect of soil Pb, Zn, Cu, and Cd morphological distribution on the control of Pb, Zn, Cu, and Cd accumulation. The results showed that the application of the three passivators significantly increased the soil pH, reduced the content of Pb, Zn, Cu, and Cd in the acid-extractable state （F1）, and increased the content of the residue state （F4）. The final passivation effect showed that RMn-nZVI>RMn>RM. In addition, the three passivators significantly reduced the accumulation of Pb, Zn, Cu, and Cd in the edible fraction of pakchoi； the RMn-nZVI treatment showed the highest reduction, with Pb, Zn, Cu, and Cd decreasing by 35.11%, 45.05%, 69.52%, and 59.63%, respectively. This study showed that the new passivation material of nano red mud loaded with nano zero-valent iron has certain potential for application in the field of remediation of heavy metal composite-contaminated soils.