基于薄膜扩散梯度技术对耕地土壤砷生物有效性评价及影响因素研究

Evaluation and Influencing Factors of Arsenic Bioavailability in Cultivated Soil Based on Thin Film Diffusion Gradient Technology

摘要:

通过采集耕地土壤样品及盆栽农作物（小白菜）试验，基于薄膜扩散梯度技术（DGT）研究了耕地土壤砷生物有效性。研究结果表明：通过回归分析比较传统Tessier法和DGT技术评价As生物有效性，两种方法测定耕地土壤As含量与农作物As含量都呈显著相关关系，但 DGT 技术相关性更高，能够更科学地反映出耕地土壤中As的生物有效性及耕地土壤的环境质量。温度为15~25℃时，As生物有效性随温度升高而升高，温度为25~30℃时，As生物有效性随温度升高略有降低。土壤pH与As生物有效性呈显著正相关关系，随着土壤pH的升高，土壤中As生物有效性增强，植物中As含量也随之增加。固化剂可以降低土壤As生物有效性，对降低土壤As污染具有一定作用。本研究进一步提升了对耕地土壤中As生物有效性的认识，可为耕地土壤As治理及农产品安全种植开发提供参考。

Abstract:

The biological availability of arsenic in cultivated soil has been studied based on film diffusion gradient technique (DGT) by collecting soil samples and pot crops (Bok choy). It is showed that traditional tessier method and DGT technique are compared to evaluate the bioavailability of As by regression analysis. There is a significant correlation between As content in cultivated soil and As content in crops determined by the two methods, but the correlation between As content and DGT technique is higher. It can reflect the biological availability of As in cultivated soil and the environmental quality of cultivated soil more scientifically. When the temperature is 15~25 ℃, the bioavailability of As increased with the increase of temperature, and when the temperature is 25~30 ℃, the bioavailability of As slightly decreased with the increase of temperature. There is a significant positive correlation between soil pH value and As bioavailability. With the increase of soil pH value, As bioavailability in soil has been enhanced, and As content in plants also increased. The curing agent can reduce the biological availability of soil As and play a certain role in reducing the pollution of soil As. This study will further improve the understanding of the biological availability of As in cultivated soil, and provide references for the management of cultivated soil As and the safe planting and development of agricultural products.