典型工业区杂草对土壤中重金属吸收特性研究

以沈阳冶炼厂厂区及其附近周围分布的一些常见植物为研究对象，探明其对重金属的吸收特性。结果表明，马齿苋、龙葵、艾蒿和酸浆的地上部分对Cd的吸收能力较强，Cd含量均接近或超过20mg．kg^-1，富集系数接近或超过1，其中艾蒿对Cd和Zn的转运系数分别为173和2．09。植物中Pb的含量均未超过130mg．kg^-1，且富集系数均在0．15以下。20种植物的地上部分Cu含量都在65mg.kg^-1以下，富集系数最大值也仅为0．15。水芹地上部分Zn含量为647．57mg．kg^-1，且富集系数为0．81，转运系数大于1。研究发现的具有潜在应用前景的重金属污染土壤修复植物，均是在自然环境采样分析测试的结果，其对重金属的最大忍耐浓度还需在实验室进一步深入研究。

Characteristics of heavy metals phytoextraction by weed species in industrial area

Phytoextraction has been recognized as an alternative technique for the remediation of soils contaminated by heavy metals.The objective of this paper is to investigate the characteristics of heavy metal phytoextaction by 20 weed species distributed in an old industrial base of Shenyang city,P.R.China.The results show that Portulaca oloraua,Solanum nigrum,Gnaphalium polycaulon and Physalis alkekengi has highly potential phytoextaction ability for cadmium in soils.The cadmium concentrations in these four plants are all more than 20 mg.kg-1,and the bioaccumulation factor(BCF) of that is near to or beyond 1,respectively.Among the four species,the transportation index(Ti),which depicts the ability of the plants to translocate heavy metals from roots to the aboveground parts,of Gnaphalium polycaulon for cadmium and zinc was 1.73 and 2.09,respectively,showing that Gnaphalium polycaulon might has a high ability for translocating cadmium and zinc from soil to its stems and leaves.The concentrations of lead and copper in the aboveground parts of the 20 investigated species are less than 130 mg.kg-1and 65 mg.kg-1,respectively,and the BCF of lead and copper is less than 0.15.Concentration of zinc in aboveground parts of Ohanthe javanica is 648 mg.kg-1,with a BCF value of 0.81,and a Ti value more than 1,which indicates important significance in remediation of zinc contaminated soil.However,as all of the plants in this study are naturally collected from the old industrial area,the maximum tolerance concentrations of heavy metals for Gnaphalium polycaulon,Physalis alkekengi and Ohanthe javanica,which have high potential phytoextraction ability,need to be studied in laboratory.