四种盐生植物对Cd Pb复合污染提取修复效果比较研究

Remediation effects of four halophytes on Cd and Pb compound pollution

在不同浓度的盐分和Cd、Pb处理下,通过砂培盆栽实验,运用富集系数、转运系数、根净吸收能力、根净转运能力、植物提取率、提取净化时间等指标,比较草木樨、盐地碱蓬、大叶补血草、野榆钱菠菜四种盐生植物对Cd、Pb复合污染的提取修复效果,结果发现:盐地碱蓬地上部生物量达13.17 g·盆^(-1),地上部Cd含量高达97.04 mg·kg^(-1),其Cd、Pb吸收与转运能力均显著高于其他三种盐生植物。适当盐分胁迫促进四种盐生植物的生长,同时对Cd和Pb的吸收有促进作用。四种盐生植物对Cd、Pb的吸收和转运存在较大差异,较高重金属浓度下Pb的吸收速率明显高于Cd的吸收速率。盐地碱蓬对Cd最大提取率为31.80%,Cd提取量达938.20μg·盆^(-1),提取净化时间为3.14年,盐地碱蓬在盐渍化与重金属复合污染土壤修复实践中有较大应用潜力与价值。

Under the different concentrations of Cd, Pb and salinity levels, the sand culture pot experiment was conducted in the greenhouse. The remediation effects on Cd and Pb compound pollution were compared among four halophytes：Melilotus suaveolens Ledeb., Suaeda salsa, Limonium gmelinii and Atripex aucheri Moq. Indicators, such as enrichment coefficient, transfer coefficient, root net absorption capacity, root net translocation capacity, extraction rate, and extraction duration, were investigated. The results showed that the biomass of Suaeda salsa was 13.17 g·pot-1, and Cd content in shoot was 97.04 mg·kg-1. Cd and Pb uptake and translocation ability of Suaeda salsa were significantly higher than those of the other three halophytes. A certain concentration of salt could promote plant growth and absorption of Cd and Pb in four halophytes. The absorption and transport of Cd and Pb were significantly different in four halophytes. For Suaeda salsa, Cd extraction rate was 31.80%, Cd extraction amount was 938.20 μg·pot-1, and the extraction duration was 3.14 years. Suaeda salsa has great potential in remediation of heavy metal contaminated saline soils.