不同钝化剂对农田土壤镉钝化稳定影响

Effects of Different Material on the Stability of Soil Cadmium

摘要: 农业土壤作为民食之基，随着多年污水灌溉和肥料的不合理使用，受到不同程度重金属污染，尤以镉(0.4~1.4 mg/kg)危害最大。农田土壤镉钝化稳定困难原因：1) 镉因其活性强，生物毒害大；2) 复杂多变的农田土壤环境；3) 不同的研究方法(不同提取剂)使得土壤钝化剂的筛选困难。本文在国内外众多学者研究的基础上，探讨不同钝化材料稳定农田土壤镉效果和机理，并找出农田土壤镉钝化存在问题。土壤镉钝化材料主要为有机还田肥料、工业大宗材料和新型试验及合成材料。动物粪便有机堆肥还田肥料效果优于植物秸秆类堆肥；工业大宗材料中羟基磷灰石、赤泥、石灰是首选土壤钝化剂；新型试验及合成材料为各种菌制剂、还原性材料以及高分子络合物。现阶段学者多关注各种菌制剂、还原性材料以及高分子络合物对土壤镉的钝化稳定。

Abstract: Agricultural soil was the basis of the food resource. It has been contaminated by heavy metals of different degrees, especially cadmium (0.4 - 1.4 mg/kg), due to sewage irrigation and fertilizers in-put. Cadmium inactivation was difficult to stabilize in farmland soils: 1) Cadmium was of activity and high biological toxicity; 2) Complex and variable farmland in soil environment; 3) Different research methods (different extractants) make soil passivation agent choice difficult. This paper is based on the previous research. The effect and mechanism of different passivation materials on stabilizing soil cadmium in farmland were discussed, and the problems of cadmium passivation in farmland soil are identified. The soil cadmium passivation materials are mainly composted organic fertilizers, industrial bulk materials and new experimental or synthetic materials. Animal manure organic composted returning fertilizer is superior to plant straw composted; hydroxyapatite, red mud, and lime are the preferred soil passivators in industrial bulk materials; new test and synthetic materials are various bacterial preparations, reducing materials, and polymer complexes. At the present stage, scholars pay more attention to the passivation stability of soil cadmium by various bacterial preparations, reducing materials and macromolecule complexes.