山东寿光设施菜地土壤砷含量及形态

Concentration and speciation of arsenic in greenhouse vegetable soil in Shouguang County of Shandong Province

通过典型区域采样调查,系统探讨了山东寿光市设施菜地中砷的含量及其形态特征.结果表明:设施菜地表层(0～20cm)和亚表层(20～40cm)土壤中总砷含量分别为8.27、7.93mg·kg-1,是对照土壤的1.19和1.23倍,易溶性砷(AE-As)含量分别为0.13、0.06mg·kg-1,是对照土壤的1.63和3.00倍;土壤中的砷主要以残渣态砷(O-As)存在,其含量占总砷的63.0%以上,其他形态砷含量依次为铁型砷(Fe-As)>钙型砷(Ca-As)>铝型砷(Al-As)>AE-As;随着种植年限的延长,土壤中AE-As含量显著增加,Al-As含量也有不同程度提高,种植15a设施菜地表层和亚表层土壤中的AE-As含量分别比对照提高了75.0%和150.0%,Al-As含量分别提高了51.6%和190.4%,而Fe-As和Ca-As含量则均有不同程度的下降.

A sampling survey was conducted in the typical areas in Shouguang County of Shandong Province to study the characteristics of arsenic （As） concentration and speciation in greenhouse vegetable soil. The total As concentration in the surface （0-20 cm） and subsurface （20-40 cm） soil was averagely 8.27 and 7.93 mg·kg-1,being 19% and 23% higher than that of the control （open field soil）,and the soluble As （AE-As） concentration was 0.13 and 0.06 mg·kg-1,63% and 200% higher than that of the control,respectively. The ratio of residual As （O-As） to total arsenic reached more than 63.0%,and the concentrations of different As speciation decreased in the order of O-As iron-bound As （Fe-As） calcium bound As （Ca-As） aluminum bound As （Al-As） AE-As. With the increasing planting years,the AE-As concentration enhanced significantly,and the Al-As concentration also increased to some degree. After 15 years planting,the AE-As concentration in surface and subsurface soil increased by 75.0% and 150.0%,and Al-As concentration increased by 51.6% and 190.4%,respectively,while the concentrations of Fe-As and Ca-As all decreased to some degree.