关键词: 铜离子污染土壤, 植物修复, 黑麦草, 玉米草, 苏丹草, 狼尾草

Abstract: In order to screen out plants with better remediation effect on copper ion contaminated soil,six plants around the site of unconventional oil and gas fields in Changling-Weiyuan including Lolium perenne,Dracocephalum moldavica,Sorghum sudanense,Pennisetum alopecuroides,Medicago sativa and Trifolium repens were selected as research varieties, and the germination rates of these six plants in different content of copper ion were measured.In addition,the test of growth adaptability of these six plants was conducted in soil with above contents of copper ion.The removal rate of copper ion in soil was calculated.The results demonstrated that,the tolerance to copper ion of Lolium perenne,Dracocephalum moldavica,Sorghum sudanense and Pennisetum alopecuroides was greater than that of Medicago sativa and Trifolium repens.The copper ion mostly concentrated in the root of Dracocephalum moldavica,Pennisetum alopecuroides and Sorghum sudanense,and the content of copper ion in the root reached 57.25,52.70 and 47.50 mg/kg respectively,when the content of copper ion in soil was 100 mg/kg.The copper ion mostly concentrated in leaf and stem of Lolium perenne,and the content of copper ion in leaf and stem reached 23.29 and 12.12 mg/kg respectively,when the content of copper ion in soil was 100 mg/kg,while the content of copper ion in root was only 1.24 mg/kg.The removal rates of Lolium perenne and Sorghum sudanense on copper ion were more than 60% when the content of copper ion in soil was 25 mg/kg,which were higher than that of Pennisetum alopecuroides and Dracocephalum moldavica,however,the removal rates of Pennisetum alopecuroides and Sorghum sudanense on copper ion reached more than 55% when the contents of copper ion in soil were more than 50 mg/kg,which were higher than that of Lolium perenne and Sorghum sudanense.Therefore,Dracocephalum moldavica can be used as restoration plants in unconventional oil and gas fields in Changling-Weiyuan area when the content of copper ion in soil is high (more than 50 mg/kg).Lolium perenne and Sorghum sudanense can be selected as restoration plants when the content of copper ion in soil is lower than 25 mg/kg.

Key words: Copper ion contaminated soil, Plant remediation, Perennial ryegrass, Corn grass, Sudan grass, Pennisetum