青岛市不同功能区常见绿化植物及土壤汞污染特征

Mercury pollution characteristics of plants and soils in different functional areas in Qingdao city

城市植物汞的污染特征,能够反映其生境特性,并能为城市汞污染防治提供科学依据。为了解青岛市植物及土壤汞污染特征,采集了青岛市不同功能区植物包括柏树(Cyparissus)、落叶松(Pinus)、法桐(Platanus)、黄杨(Euonymus)、冬青(Ilex),并同步采集相应表层土壤样品,采用冷原子吸收法测定总汞含量,研究汞的含量及分布。结果表明,不同的植物对汞的吸收累积能力不同,汞含量范围为7.2～95.7ng·g-1,其中冬青和黄杨对汞的吸收累积能力高于其他植物,分别达到59.79ng·g-1和51.85ng·g-1。植物的不同器官对汞的吸收能力不同,一般表现为树茎<树叶。不同功能区植物含汞量有很大的差异,植物在老工业区的汞含量最高,在新经济技术开发区的含量较低。道路两旁的植物中汞含量较高,说明交通是影响植物汞含量的一个重要因素。老工业区土壤汞含量最高于其它功能区,但植物中的汞含量和土壤中的汞含量没有显著的相关性。青岛市表层土壤汞含量低于中国其他城市的汞含量水平。青岛市常见绿化植物只有老工业区为中度污染,其它地区均为轻度污染。

Mercury pollution characteristics of plants in city could indicate plant environmental exposure and provide sciontifie information for Hg pollution prevention. In order to study the status of mercury contamination in Qingdao city, typical plants in different zones including Cypariss, Pinus, Platanus, Euonymus and llex, and surface layer soils were gathered. CVAAS method was used to determine the total mercury concentration. The result showed that mercury contents in plants were 7.2 - 95.7 ng·g^-1 and different species were various in mercury accumulation. The mercury contents of Euonymus and llex were 59.79 ng·g^-1 and 51.85 ng.gl, respectively, higher than the other plants. There were differences of mercury contents in organs of plant, stem〈leaf g,enerally Plant Mercury concentration in old industrial zone was highest, while lowest in the new economic development zone. Plant mercury in roadside was higher, due to the discharge by vehicles. As to the mercury pollution Of surface layer soil, the old industrial zone was higher than the other sites. There was no remarkable relevance between the concentrations in plant and in soil due to Hg in the leaf coming from the atmosphere mainly. Mercury concentration of surface layer of Qiingdao city was lower than the other cities in China. Plant mercury pollution in Qingdao city did not reach to the degree of severity. The old industrial zone was moderate-graded, and the other regions were low-graded.