红树白骨壤幼苗对水中重金属的吸附性能研究

Removal of Heavy Metal Ions with Avicennia marina Seedling

【目的】针对广西近岸海域重金属污染越来越严重的问题,研究红树白骨壤幼苗对水中重金属(Cu,Pb,Zn,Cd)的吸附去除性能。【方法】红树白骨壤幼苗采用砂培法由胚轴栽培而得,配制不同浓度混合重金属培养液对红树白骨壤幼苗胁迫培养35d后采用原子吸收光谱法测定其体内的重金属含量。【结果】随着培养液中重金属浓度的升高,红树白骨壤幼苗体内的重金属含量也逐渐增加,最高含量分别达到Cu 980.78μg/g,Pb 1623.03μg/g,Zn 446.21μg/g,Cd 69.41μg/g。红树白骨壤幼苗不同部位对重金属的积累能力普遍是叶部最少,茎部次之,大部分都积累在根部。红树白骨壤幼苗的根、茎对Zn的输送能力最好,其次是Cu和Cd,对Pb的输送能力最差。【结论】红树白骨壤幼苗对4种重金属都有较好的吸附能力,尤其是对Pb和Cu的吸附去除效果更好,是一种性能良好的近岸河口重金属污染修复植物。

【Objective】The absorption capabilities of Cu,Pb,Zn and Cd by Avicennia marina seedling were investigated to reduce the severe pollution in the offshore marine areas of Guangxi.【Methods】The Avicennia marina seedlings were obtained from the hypocotyls planted in sands with hoagland＇s fluid,and then were cultured in hoagland＇s fluid with different concentrations of heavy metals.After 35day＇s cultivation,the contents of heavy metals in Avicennia marinaseedlings were determined by microwave digestion and atomic absorption spectrometry.【Results】The increase of heavy metals concentration in the culture fluids led to the increase of heavy metals in the seedlings.The highest amount of heavy metal is 980.78μg/g of Cu,1623.03μg/g of Pb,446.21μg/g of Zn and 69.41μg/g of Cd,respectively.The amounts of heavy metals in different part of seedlings is root stem leaf.This result meant that the heavy metal contents mainly were accumulated in root.The transport capability for different kind of heavy metals in the root and stem of seedlings were different.The transportation from easy to difficult in seedling is ZnCuCdPb.【Conclu-sion】The Avicennia marina seedlings showed good absorption capabilities to 4 kinds of heavy metals in aqueous solution,especially to Pb and Cu.The Avicennia marinais a prospective plant for restoring the heavy metal pollution in estuary and offshore marine areas.