降低烟草吸收土壤镉的钝化技术及其机理研究进展

Research progress on passivation technologies and their mechanism of reducing soil cadmium uptake by tobacco

  • 摘要: 烟草是重要经济作物,且极易吸收镉(Cd),烟草中Cd已成为Cd进入人体的主要来源之一,通过调控措施降低烟草叶片Cd浓度,对保障烟草的品质安全与人体健康具有重要意义。综述了降低烟草Cd浓度的土壤Cd钝化技术,阐明了钝化剂的钝化机理(吸附、离子交换、沉淀、络合和离子拮抗作用等)及影响烟草Cd浓度的因素(包括土壤Cd浓度与化学形态、土壤pH、氧化还原电位、有机质浓度、阳离子交换容量、竞争性金属离子浓度等),阐述了常用钝化剂(石灰、羟基磷灰石、金属氧化物、生物炭、有机肥、海泡石、沸石和膨润土等)的钝化效率及其在实际应用的参数条件,并提出明晰烟草Cd含量标准体系、发展新型钝化材料、结合分子生物学技术调控等建议,以期为降低烟草Cd含量提供基础数据和技术参考。

     

    Abstract: Tobacco is an important economic crop which is readily to uptake cadmium (Cd) from soils, rendering it to be one of the main source of Cd to human bodies. Therefore, reducing Cd content in tobacco leaves through regulation and control measures is important to ensure tobacco quality, safety and human health. The soil Cd passivation technologies to reduce Cd content in tobacco were summarized, and the passivation mechanism of passivators, including adsorption, ion exchange, precipitation, complexation and ion antagonism, was expounded. The factors affecting Cd content in tobacco were also analyzed, including soil Cd concentration and chemical forms, soil pH, redox potential, organic matter concentration, cation exchange capacity, and competitive metal ions. The passivation efficiencies of normal passivators and the parameter conditions in the applications were illustrated, including lime, hydroxyapatite, metal oxides, biochar, organic fertilizer, sepiolite, zeolite and bentonite. Some suggestions were proposed to provide basic data and technical reference for the reduction of Cd content in tobacco, including clarifying the standard system of tobacco Cd content, developing new passivation materials and using molecular biology technologies, etc.

     

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