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以北京7种常见经济林树种为研究对象,利用微波消解仪进行微波消解,并用ICP-MS电感耦合等离子体质谱和电感耦合等离子发射光谱仪测定了植物叶片和土壤中重金属含量。结果表明:核桃、梨、苹果、桃和枣叶片中重金属元素含量大小排序一致为Zn>Cu>Cr>Ni>Pb>As>Cd,且各树种中Zn和Cu含量较其余各元素含量明显偏高,范围值分别为12.57~23.90mg·kg~(-1)和4.52~10.25mg·kg~(-1);7种经济林吸滞重金属元素的能力差异显著,其中,桃对Cr(5.94mg·kg~(-1))、Ni(5.60mg·kg~(-1))吸滞能力较强,梨吸滞Cu(10.25mg·kg~(-1))能力较强,而樱桃和枣则吸滞Zn元素的能力较强,分别为23.80、23.90mg·kg~(-1);不同季节各树种叶片吸滞Zn、Cu、Ni、Cr季节变化趋势存在明显差异,部分树种在冬季吸滞量最高,部分树种则在夏季最高,但各树种叶片Ni含量最小值均在秋季,对Pb、As和Cd的吸滞量变化特征呈完全一致的变化规律,均在冬季吸滞量较高;林木叶片中重金属含量与土壤中重金属含量大部分相关性不显著(P>0.05)。
Seven common forest species in Beijing were selected as the research object. Microwave digestion was used to perform microwave digestion. The contents of heavy metals in plant leaves and soil were determined by inductively coupled plasma mass spectrometry (ICP-MS) and inductively coupled plasma atomic emission spectrometry (ICP-MS). The results showed that the contents of heavy metals in walnut, pear, apple, peach and jujube leaves were in the order of Zn> Cu> Cr> Ni> Pb> As> Cd, and the content of Zn and Cu in each species was significantly High and ranged from 12.57 to 23.90 mg · kg -1 and 4.52 to 10.25 mg · kg -1, respectively. There were significant differences in the ability of seven economic forest to absorb heavy metals, · Kg ~ (-1)), Ni (5.60 mg · kg ~ (-1)) had better ability of absorbing and sinking Cu (10.25 mg · kg ~ (-1)), while that of cherry and jujube The ability of absorbing Zn was stronger, which was 23.80 and 23.90 mg · kg -1, respectively. There was a significant difference in seasonal changes of Zn, Cu, Ni and Cr in the leaf sequestration in different seasons, The highest amount of stagnation and the highest percentage of some tree species in summer. However, the minimum value of Ni in leaf species of all species was in autumn, and the changes of the sorption characteristics of Pb, As and Cd were completely consistent. There was no significant correlation between heavy metal content in forest leaves and heavy metal content in soil (P> 0.05).