【作者】 崔爽；

【导师】 周启星；

【作者基本信息】 中国科学院研究生院（沈阳应用生态研究所） ， 生态学， 2007， 博士

【摘要】 近年来,土壤重金属污染的植物修复得到世界各国的重视,将花卉植物应用于污染土壤修复方面的研究应该说是刚刚兴起,但具有巨大的修复潜力。我国的铅污染形势十分严峻,大量的铅污染土壤亟待修复。铅在土壤中生物有效态的含量很低,因此必须采用一些有效的强化手段(如施用螯合剂)来提高植物的修复效率。本研究以草本花卉为研究对象,通过室外盆栽筛选实验,分析了30种花卉植物对Pb的耐性特征和积累特性,并与螯合诱导技术相结合,强化花卉植物的修复效果,同时尽量减少可能造成的环境风险和健康危害。根据超积累植物应具备的4个基本特征,对参试的30种花卉植物进行盆栽初步筛选分析。实验结果表明,对Pb污染耐性较强且积累能力较强的花卉有9种;对Pb污染耐性较强但积累能力较弱的花卉共12种,这些植物在植物稳定修复方面可能有一定价值;其它9种花卉对Pb污染耐性较弱且积累能力较弱,是Pb的非超积累植物。盆栽浓度梯度筛选实验表明,满天星和火炬鸡冠是具有铅超积累植物特征的花卉。满天星转移系数大于1,地上部铅含量超过了铅超积累植物需要达到的临界含量标准,但对高浓度铅污染耐性较差且富集系数小于1;火炬鸡冠耐性较强且地上部铅含量超过了铅超积累植物需要达到的临界含量标准,但转移系数和富集系数均小于1。水培实验表明:EDTA、NTA强化效果较好;矮牵牛幼苗土培强化实验确定先加EDTA,一周后加入NTA,且二者的比例为2:1时修复效率最高;在7种铅积累能力较强的花卉植物成熟后,收获前按上述方法分两次施加混合螯合剂,实验结果证实此修复方法具有有效性、经济性、安全性和公众可接受性。更多还原

【Abstract】 Phytoremediation is a cost effective and environmentally friendly alternative, and applying flowers to phytoremediation is promising. Lead (Pb) contamination in different ecosystems has run to serious degree due to industrial processes,therefore, it is an urgent and challenging task to remediate Pb-contaminated sites with appropriate remediation methods. However, the bioavailability of Pb in soils is low and the plant capacity to absorb this contaminant is weak. Chelator-enhanced phytoremediation is considered as a suitable method for the extraction of Pb by plants.In order to promote the effective and economic remediation of soils contaminated with Pb, a field-screening hyperaccumulators study from 30 varieties of flower was carried out to determine characteristics of flowers enduring and accumulating Pb by field pot-culture experiments. Chelate-induced phytoextraction with high Pb-accumulative flower species provide theory and practice for the clean-up of heavy metal from polluted soils.The results showed that 9 varieties had strong Pb-endurance and high Pb-accumulative ability, 12 varieties possessed strong Pb-endurance and weak Pb-accumulative ability, and others were weak Pb-tolerance plants with weak Pb-accumulative ability.According to the concentration gradient experiment, Gypsophlia elegans and Celosia cristata pyramidalis generally prossessed basic characteristics of hyperaccumulators. The translocation factor and concentration of Pb in Gypsophlia elegans’s shoot were satisfied the characteristics of hyperaccumulators, however, it had weak endurance to severe Pb pollution and the enrichment coefficient was less than 1. Celosia cristata pyramidalis possessed strong tolerant ability and concentration of Pb in its shoot was higher than 1000 mg kg-1, while the translocation factor and enrichment coefficient were less than 1.The chelate-induced phytoextraction experiment suggested the application of two different chelating agents, i.e. EDTA and NTA, is effective. Among the tested application ratios of 1:1, 1:2 and 2:1 (EDTA: NTA), 2:1 of EDTA: NTA was the most efficient ratio for remediation, and NTA was applied one week after EDTA. The combined application of EDTA and NTA before harvest was effective, economical, safe and public acceptable.更多还原