污泥堆肥土地利用中重金属在几种观赏植物中富集作用的研究

采用小区试验的方法,研究了上海曲阳污水厂污泥堆肥土地利用过程中小叶黄杨、海桐、杜鹃、孔雀草、一串红等植物的根部对重金属的吸收及富集作用。结果表明:几种植物对Cu均表现出比Zn更强的富集能力,而对Cd、Pb的富集能力很弱,对Cu的富集尤以小叶黄杨须根的能力最强,最高可以达到种植土壤中Cu浓度的4倍左右;对小叶黄杨、海桐、杜鹃3种灌木而言,其须根对重金属的吸收能力显著高于主根;就不同重金属的绝对吸收量而言,几种植物对Zn的吸收总量都是最高的。几种灌木类植物的须根中的Zn含量,总体呈现随土壤中Zn含量增加而上升的趋势。

Adsorption of Heavy Metals by Some Ornamentals from Mixed Soils Containing Composted Sewage Sludge

The adsorption process and accumulation of heavy metals by ornamentals, including Buxus Microphylla Sieb et Zucc, Pittosporum Tobira, Rhododendron Simsii Planch, Tagetes Patula and Salvia Splendens, from the soils were studied in the mixed soil system containing composted sewage sludge. The results showed that all these five plants had a relatively strong enrichment effect on element Cu, but very weak for Cd and Pb. The fibres of Buxus Microphylla Sieb et Zucc exhibited the highest adsorption ability for Cu, the concentration in its fibres were four times of that in soils. For the shrubs including Buxus Microphylla Sieb et Zucc, Pittosporum Tobira and Rhododendron Simsii Planch, their fibres showed a higher adsorption ability than their taproots. Based on the total concentration of different heavy metals in these plants, the content of Zn in every plant held the first place among the detected heavy metals. In the three kinds of shrubs, the content of zinc in fibres increment gradually with the increment of zinc concentrations in the mixed soils.