植物叶片含硫量在大气SO_2污染评价中的应用

Applications of evaluation on leaf sulfur content in the atmosphere of SO_2 pollution

城市绿化植物不仅对大气SO2污染物具有净化作用,而且能够指示大气SO2污染状况.根据西安市环境空气质量报告,在7区13个采样点选取了7种具有代表性的绿化植物,利用硫酸钡比浊法分别测定其吸硫量,从中选取国槐和樱花作为环境评价的指示树种,采用单因子评价法对研究区域的污染状况进行评价.研究结果表明,植物叶片的净相对含硫量与大气SO2浓度呈正相关,其相关系数为0.870 9.国槐和樱花的吸硫量最大、抗污性最强,可作为评价的指示树种;西安市6个行政区大气SO2污染状况等级从重到轻依次为莲湖区、灞桥区、新城区、碑林区、雁塔区和未央区.其中莲湖区污染等级为Ⅳ级,而未央区污染等级为Ⅱ级.

Urban green plants not only have a purifying effect on atmospheric pollutants such as SO2,but also can indicate atmospheric SO2 pollution.Based on a recent report on the environmental air quality in Xi′an,seven typical green plants are selected from 13 sampling points in Xi′an and are measured for sulfur content of their absorption respectively by barium sulfate turbidimetric method.Meanwhile,Sophora japonica and cherrytrees are selected as an environmental indicator species and evaluated in the study areas by single-factor evaluation method.The results show that the net relative sulfur content of plant leaves are positively correlated with the concentration of atmospheric SO2 which is the correlation coefficient of 0.870 9.The largest amount of sulfur absorbed and the strongest anti-pollution of the Sophora japonica and cherry tree can be used as an indicator species according to the research.As a result,the levels of atmospheric SO2 pollution are followed by Lianhu District,Baqiao District,Xincheng District,Beilin District,Yanta District and Weiyang District in Xi′an,of which the levels of atmospheric SO2 pollution at Lianhu District is in the fourth place,while WeiYang District the second.