基于DGT技术的土壤铅生物有效性评价研究  

Assessment Bioavailability of Lead in Soils Based on Diffusive Gradient in Thin-films Technique

作　　者：代允超[1,2] 张育林 吕家珑[1,2] DAI Yunchao;ZHANG Yulin;LU Jialong(College of Resources and Environment,Northwest A＆F University,Yangling,Shaanxi 712100,China;Key Laboratory of Plant Nutrition and the Agri-environment in Northwest China,Ministry of Agriculture,Yangling,Shaanxi 712100,China)

机构地区：[1]西北农林科技大学资源环境学院,陕西杨凌712100 [2]农业部植物营养与农业环境重点实验室,陕西杨凌712100

出　　处：《农业机械学报》2018年第9期267-274,共8页Transactions of the Chinese Society for Agricultural Machinery

基　　金：农业部公益性行业科研专项(200903015);"十二五"国家科技支撑计划项目(2015BAD22B02);陕西省科技创新统筹项目(2016KTZDNY03-01)

摘　　要：采集我国15个省份的耕作土壤进行盆栽试验,通过外源添加不同浓度梯度的Pb并种植小白菜,比较梯度薄膜扩散技术(Diffusive gradients in thin-films,DGT)与传统化学方法(土壤溶液法、EDTA法、HAc法、CaCl_2法和全量法)评价土壤中Pb生物有效性。简单回归分析表明,各评价方法测定的土壤Pb含量与小白菜Pb含量都呈显著相关关系,但DGT技术相关性(R^2=0.97)最高。通过逐步多元线性回归分析,融合土壤pH值、有机碳(OC)含量、阳离子交换量(CEC)、粘粒含量等土壤基本理化性质,建立多元回归模型,结果表明:各传统评价方法融合了pH值、OC含量等土壤性质,R^2较对应的简单回归分析有所提高,都能用于评价土壤Pb的生物有效性,但通过DGT技术所构建的模型方程(R^2=0.97,p<0.01)几乎不受土壤性质的影响,且较传统化学方法相关性更高,因此,DGT技术是一种可以用于评价土壤中Pb生物性的较优方法。There is no universally accepted approach for evaluating lead（Pb） bioavailability in soil. The diffusive gradient in thin-films（DGT） technique is a promising tool which has been used for evaluating the bioavailability of heavy metals in water and sediment. The principle of DGT is based on Fick＇s first law of diffusion. The ability of this technique to estimate Pb bioavailability in soils was compared with the abilities of other traditional chemical extraction techniques（soil solution,ethylene diamine tetraacetic acid（EDTA）,acetic acid（HAc）,calcium chloride（CaCl2）,and pseudo-total Pb methods） based on a greenhouse experiment using Brassica chinensis grown in 15 soils from different provinces of China. In addition,whether these methods were independent of soil properties were assessed. Correlations between the plant and soil Pb concentrations measured with the traditional extraction techniques were dependent on the pH value and organic carbon（OC） content,indicating that these methods were influenced by the soil properties. The regression coefficients（R^2） were increased when these prediction models,including soil properties（pH value and OC） though the stepwise multiple linear regressions compared with simple linear regressions besides DGT method. In contrast,the DGT measurements were independent of the soil properties and showed a higher correlation coefficient compared with that of the traditional techniques.And the prediction model built by DGT（R^2= 0. 97,p〈 0. 01） showed a highest R-2. Hence,the DGT technique was better and should be preferable for assessing Pb biological effectiveness in different soil types.

关 键 词：小白菜 铅 生物有效性 梯度薄膜扩散技术 传统化学方法 

分 类 号：S132[农业科学—农业基础科学] X53[环境科学与工程—环境工程]