土壤环境质量基准中Cd限量指标的推算  

Estimation of cadmium limits for soil environmental quality standard

作　　者：高树芳[1] 王果[1] 苏苗育[1] 罗丹[1] 

机构地区：[1]福建农林大学资源与环境学院,福建福州350002

出　　处：《福建农林大学学报（自然科学版）》2006年第6期644-647,共4页Journal of Fujian Agriculture and Forestry University:Natural Science Edition

基　　金：福建省科技厅重点资助项目(2003Y026);福建省环保局重点项目

摘　　要：以采自福建省主要城市郊区耕地表层土壤和相应蔬菜可食用部分Cd含量的数据为依据,提出一种土壤环境质量基准中有害元素限量指标的推算方法.整个推算过程包括指标类型选择、高风险指示作物确定和限量推算3个步骤.与土壤Cd全量相比,二乙三胺五乙酸(DTPA)-CaC l2-三乙醇胺(TEA)提取的有效Cd能更好地预测土壤Cd的生物有效性,因此选择DTPA提取的土壤有效Cd作为土壤Cd的指标类型.在15种供试蔬菜中,空心菜可食用部分对土壤Cd的富集能力最强,同时又是本区域消耗量最大的蔬菜之一,因此将其定为高风险指示作物.根据空心菜含Cd量与土壤有效Cd含量之间的回归方程推算出来的土壤有效Cd的限量为0.1 mg.kg-1.通过土壤有效Cd与全Cd之间的回归方程可推算出相应的全Cd限量为0.6 mg.kg-1.A method for estimating limits of toxic elements for soil environmental quality standard was proposed based on the Cd content in the surface soils and corresponding vegetables collected from the suburbs of some main cities of Fujian Province. Three steps were included in this estimation procedure, selection of indicative parameter, selection of hlghest-risk crop and estimating the limit value. The available Cd extracted by diethytenetriaminepentaacetic acid （DTPA） - CaCl2 - triethanolaminc （TEA） （ pH = 7.3 ） was better than total Cd in predicting the Cd bioavailability in these soils and consequently adopted as the indicative parameter for Cd limit. It was shown that water spinach （ Lpomoea aquatics Forsk. ） was much stronger than the other 14 vegetables in accumulating Cd from the soils, so it was chosen as the highest-risk vegetable for estimating the Cd limit. The DTPA-extractable Cd limit value estimated from the regression equation between the Cd concentration in the edible parts of water spinach and the available Cd in the soils was 0.1 mg·kg^-1 The corresponding total Cd limit value was 0.6 mg· kg^-1 calculated from the correlation equation between the DTPA-extractable Cd and total Cd of the vegetable soils.

关 键 词：CD 土壤 环境质量基准 限量 

分 类 号：X131.3[环境科学与工程—环境科学] X171.5