植物混种原位修复多环芳烃污染农田土壤

通过比较实验前后土壤微生物主要类群数量、PAHs降解菌数量、土壤PAHs含量和植物不同部位PAHs含量变化,评价植物单种和混种野外原位修复多环芳烃(PAHs)污染农田土壤的效果。结果显示,150 d天生长期内,黑麦草/小麦混种及黑麦草/蚕豆混种修复效果最好,对土壤PAHs总量的降解率分别达到了59.4%和64.8%。同时,这2个混种处理土壤细菌、真菌和PAHs降解菌数量分别显著高于相应的小麦、蚕豆和黑麦草单种处理。植物不同部位PAHs含量高低次序为根部>茎叶≈籽粒。混种模式下,蚕豆和小麦不同部位PAHs含量比单种模式的不同程度降低,特别是籽粒部。植物混种模式不仅显著提高了土壤PAHs的降解率,还降低了农作物体内PAHs含量,实现了边生产边修复,在污染农田土壤修复领域有着广阔的应用前景。

In situ phytoremediation of PAHs contaminateds soils in a mixed cropping system

In-situ phytoremediation of PAHs contaminated soils in the monoculture and mixed cropping was investigated by the number of soil microbe,PAHs-degrading microbe,PAHs concentration in plant and soil.The results showed that,removal rates of PAHs in mixed cropping treatments of ryegrass/horsebean and ryegrass/wheat were 59.4% and 64.8%,respectively.At the same time,the numbers of soil bacterium,fungi and PAHs-degrading microbe in ryegrass mixed cropping treatments were significantly more than those of the monoculture cropping of wheat,horsebean and ryegrass.In different parts of plants,the order of PAHs concentration was as following: root>shoot≈seed.PAHs concentration within different parts of plants in mixed cropping treatments decreased at different degrees when contrasted with those of monoculture treatments,especially in seed.The results suggested in-situ phytoremediation of PAHs contaminated soils in a mixed cropping system improved removal efficience of PAHs in soils and decreased acccumulation of PAHs in crops,and had a broad prospect for realization of the PAHs remediation in the farming agricultural soils.