摘要
通过对关中平原西安污灌区、宝鸡峡灌区、交口灌区关中娄土剖面土壤样品的采集、监测,重点分析了对土壤环境及人体危害较大的Cd、Pb、As、Cr等重金属元素在土壤剖面中的垂直分布和淋失迁移的特征。结果表明:在长期污灌的条件下,关中娄土剖面中的Cd、Pb、As、Cr含量具有在土壤耕作层富集的特征,关中娄土剖面中的Cd、Pb含量具有从耕作层向土壤下层递减的趋势,As、Cr含量从耕作层向土壤下层递减的趋势不明显。关中娄土剖面中的Cd、Pb、As、Cr含量在80～100cm土壤粘化层中均具有明显增高的趋势,为土壤剖面中重金属元素垂直分布的转折层。关中娄土剖面中重金属元素的淋失率具有Cd>Cr>As>Pb的特征,且土壤剖面中重金属的淋失率具有从耕作层、犁底层、老耕层、古耕层、粘化层垂直递增的趋势。当污灌区土层中的重金属含量高时,土壤剖面中的重金属元素Cd、Cr、As、Pb均可向土壤下包气带土层淋虑迁移,对地下水的安全构成威胁。
Based on a study of monitored soil samples collected from Xi＇an sewage irrigated area, Baoji gorge irrigated area and Jiaokou irrigated area in Guanzhong plain, the authors investigated vertical distribution and leaching migration of such heavy metals as Cd, As, Cr and Pb in the Guanzhong tier soil profile. These elements can seriously endanger soil environment and human health. The following conclusions have been reached： Cd, Pb, As and Cr tend to be concentrated in the cultivated horizon under the condition of long-term sewage irrigation, the Cd and Pb content tends to decrease frorn the cultivated horizon to its underlying layer, whereas the AS and Cr content fails to show such a decreasing tendency. The Cd, Pb, As, Cr content tends to increase in the soil layer of 80-100 cm, which might be the inflection layer in the vertical distribution of heavy metals. The water washing coefficients of heavy metals are characterized by Cd〉Cr 〉 As〉 Pb, and the water washing coefficients of heavy metals have an increasing tendency frorn the cultivated horizon through plow pan, old plow layer and ancient plow layer to viscid layer. Where the content of heavy metals is high in soil layer of the sewage irrigation area, Cd, Cr, As and Pb can eluviate and migrate towards the underlying aeration zone, thus threatening the security of underground water.
出处
《地球学报》
EI
CAS
CSCD
北大核心
2008年第1期109-115,共7页
Acta Geoscientica Sinica
基金
中国科学院地球环境科学研究所黄土与第四纪地质国家重点实验室开放基金项目(编号:SKLLQG0704)
国家科技部软科学研究项目(编号:2004DGS3D026)
陕西省科技发展计划重大项目(编号:2003K12-G5)联合资助
关键词
关中娄土剖面
重金属元素
垂直分布规律
Guanzhong tier soil profile
heavy metal elements
regularity of vertical distribution
