螯合剂和泥炭对苎麻吸收土壤镉的影响  

Extraction of Cd by Ramie from Soils as Affected by Applications of Chelators and Peat

作　　者：沈莉萍[1] 宗良纲[1] 蒋培[1] 刘卫星[1] 姜博[1] 陈亚华[2] 

机构地区：[1]南京农业大学资源与环境科学学院,南京210095 [2]南京农业大学生命科学学院,南京210095

出　　处：《环境科学》2009年第9期2767-2772,共6页Environmental Science

基　　金：国家高技术研究发展计划(863)项目(2006AA102404)

摘　　要：通过生物盆栽试验研究了施用螯合剂(EDTA、柠檬酸)与泥炭对强化苎麻修复重金属镉污染土壤的作用.结果表明,施加泥炭能改善土壤的理化性质,增加苎麻的生物产量,泥炭单施、螯合剂(EDTA、柠檬酸)和泥炭的组合措施的相对产量分别为1.23、1.13和1.41,因此泥炭和柠檬酸配施处理更有利于植物生长.就植物吸收镉能力来说,螯合剂(EDTA、柠檬酸)和泥炭的配施处理能更好地促进苎麻对镉的吸收,其土壤交换态镉所占镉形态质量分数为61.6%和58.3%,具有强化植物修复的效果.螯合剂(EDTA、柠檬酸)和泥炭2种组合方式的地上部富集系数分别为1.33和1.32,大于单施(EDTA、柠檬酸和泥炭)处理1.11、1.11和1.05,具有较好的富集效应,同时螯合剂(EDTA、柠檬酸)和泥炭的组合处理对土壤镉的净化率分别达到了1.13%和1.22%,而柠檬酸和泥炭配施具有较大的生物量,使植株总镉量略高于EDTA与泥炭的组合处理,因而更有利于镉污染土壤的修复.因此,利用螯合剂和泥炭的组合修复措施对强化苎麻修复镉污染土壤能取得更佳的效果.Pot experiments were performed to study the effectiveness of chelators （EDTA, citric acid） and peat in enhancing phyremediation of heavy metal Cd by ramie. The results showed that peat increased the ramie＇s biomass by improving soil＇s physical and chemical properties, and the relative yields of peat alone, ehelators（EDTA, citric acid） combined with peat were 1.23, 1.13 and 1.41 respectively. So the combination of citric acid and peat was more useful for growth of the ramie. As far as improving Cd uptake was concerned, it seemed that the combination of chelators with peat significantly promoted Cd uptake by the plant, and the percent of changeable Cd in soil were 61.6% and 58.3 % . In addition, it had better bioaccumulation effects to combine with chelators and peat, of which Cd bioaecumulation coefficients were 1.33 and 1.32, compared to 1.11, 1.11 and 1.05 in application of peat, EDTA and citric acid respectively. What＇ s more, cadmium removal rates in soil were up to 1.13% and 1.22% respectively in applications of two kinds of chleators（EDTA, citric acid） combined with peat. Therefore, it had better effects of phytoremediation to accumulate more cadmium amounts by combining with citric acid and peat because of more biomass. In conclusion, the phytoremcdiation by ramie can be more effective when chelators and peat were combined and added to soils.

关 键 词：螯合剂 泥炭 镉 植物修复 苎麻 

分 类 号：X53[环境科学与工程—环境工程]