摘要
螯合剂可增加重金属的生物可利用性,强化植物的富集作用.以三叶草为研究对象,通过盆栽试验考察不同浓度可生物降解螯合剂谷氨酸N,N-二乙酸(GLDA)对三叶草修复重金属Cd污染土壤的影响机制.结果表明,低剂量GLDA能显著促进三叶草的生长,其中以2.5 mmol·kg^-1的处理浓度三叶草生物量最高,达到对照组的1.30倍;不同浓度GLDA均能提高三叶草各部分的Cd含量,总体而言,5 mmol·kg^-1GLDA的处理效果最为理想,根部、地上部分和整株Cd含量分别为对照组的3.57、4.69和4.67倍;GLDA能显著增加土壤有效态Cd含量,促进三叶草根部对其直接吸收,并较好地转运至地上部分;通过拟合土壤理化性质、GLDA与三叶草Cd含量的线性关系得出的预测模型,可为今后土壤-三叶草富集效果的研究提供参考.研究表明,在强化植物修复重金属Cd污染土壤方面,生物可降解螯合剂GLDA具有潜在应用前景.
Chelating agents can increase the bioavailability of heavy metals and enhance their enrichment in plants.The effects of different concentrations of biodegradable chelating agent L-glutamic acid N,N-diacetic acid(GLDA)on the remediation of heavy metal-contaminated soil by super-enriched plant Trifolium repens were investigated by pot experiments with Cd-contaminated soil.Results show that low-dose GLDA could significantly promote the growth of Trifolium repens,and the biomass of Trifolium repens was the highest at 2.5 mmol·kg^-1-GLDA,which was 1.30 times that of the control group.Different concentrations of GLDA can increase Cd content of various parts of Trifolium repens.In general,the treatment effect of 5 mmol·kg^-1 GLDA was ideal.In this scenario,the root,aerial parts,and whole Cd content were 3.57,4.69,and 4.67 times of the control group,respectively.GLDA can significantly increase the available Cd content in soil,promote direct absorption at the Trifolium repens roots,and provide better transport to the aerial parts.The prediction model obtained by fitting the linear relationship between physical and chemical properties of soil indicates that GLDA and Trifolium repens Cd content can provide references for the future research of soil-Trifolium repens enrichment.Studies have shown that the biodegradable chelating agent GLDA has potential applications for enhancing phytoremediation of heavy metal Cd contaminated soil.
作者
贺玉龙
余江
谢世前
李佩柔
周宽
何欢
HE Yu-long;YU Jiang;XIE Shi-qian;LI Pei-rou;ZHOU Kuan;HE Huan(College of Architecture and Environment,Sichuan University,Chengdu 610065,China;Institute of New Energy and Low Carbon Technology,Sichuan University,Chengdu 610065,China)
出处
《环境科学》
EI
CAS
CSCD
北大核心
2020年第2期979-985,共7页
Environmental Science
基金
国家重点研发计划项目(2018YFC1802605)
四川省科技重点攻关项目(2017GZ0383,2017SZ0181).
关键词
植物修复
重金属
镉
谷氨酸N
N-二乙酸(GLDA)
三叶草
可降解螯合剂
phytoremediation
heavy metals
cadmium
L-glutamic acid N,N-diacetic acid(GLDA)
Trifolium repens
degradable chelating agent
