钝化剂在烟草植物修复铅镉污染土壤中的作用简

重金属钝化剂可以改变土壤中重金属的形态，降低其在土壤中的有效浓度、植物毒性及生物有效性，影响污染土壤中植物的生长及其对重金属的吸收。在温室盆栽条件下研究了施加羟基磷灰石（HA）、纳米羟基磷灰石（nHA）、纳米零价铁（nFe⁰）和纳米TiO₂（nTiO₂）对烟草植物修复铅镉污染土壤的作用。结果表明，HA降低土壤中Pb、Cd的有效性、促进烟草生长、增加了烟草叶、茎、根中Cd的吸收量和根系中Pb的吸收量，有利于Pb、Cd的钝化和植物修复。nHA也可以降低土壤中Pb、Cd的有效性，增加了烟草叶中Cd的吸收量，有利于Pb、Cd的钝化和Cd的植物提取。nFe⁰和nTiO₂对于土壤Pb和Cd的钝化作用和植物修复均没有显著影响。综合来看，HA最适合应用于烟草植物修复铅镉污染土壤。

Role of immobilization amendments in phytoremediation of Pb-Cd-contaminated soil using tobacco plants

Immobilization amendments can change the forms of heavy metals in soil, decrease their available fractions, phytotoxicity and bioavailability, and thus affect the growth and heavy metal uptake of plants grown in polluted soil. A greenhouse pot culture experiment was conducted to study the phytoremediation of Pb-Cd-contaminated soil using tobacco plants assisted by several immobilization amendments, including hydroxyapatite (HA), nano-hydroxyapatite (nHA), nano-zero-valent iron (nFe⁰) and nano-TiO₂ (nTiO₂). Results showed that HA decreased the available concentrations of Pb and Cd in soil, promoted tobacco growth, and increased Cd uptake in stems, leaves and roots and Pb uptake in roots, which was beneficial for immobilization and phytoremediation of Pb and Cd. Application with nHA also decreased Pb and Cd availability in soil, and increased Cd uptake in tobacco leaves, thereby contributing to immobilization of Pb and Cd and phytoextraction of Cd. However, nFe⁰ and nTiO₂ showed no significant role in either immobilization or phytoremediation of Pb and Cd. Overall, HA may be the most suitable immobilization amendment used for phytoremediation of Pb-Cd-contaminated soil using tobacco plants.