天津市不同土地利用类型土壤中多环芳烃的含量特征

Contents of PAH compounds in different types of soils in Tianjin area

本文分析了天津不同土地利用类型表层土壤若干多环芳烃组分的含量特征及污染水平。结果显示 ,城市绿地土壤中多环芳烃的含量最高 ,污灌农田土壤中一些组分的含量也较高 ,但多数组分与普通农田、荒地等其他土地利用类型相差不大 ;在 6种土地利用类型中 ,低环 /高环在大部分地区小于 1,说明天津地区多环芳烃污染主要以燃烧源为主。芘 /苯并 (a)芘参数值则反映出市区绿地土壤受交通污染的影响比较大 ;各种土地利用类型土壤表层均受到了一定程度的多环芳烃污染 。

Polycyclic Aromatic Hydrocarbons (PAHs) have been identified as important pollutants in the environment Researches on the pollution situation of PAHs in soils have been carried out extensively in many countries In comparison, few large scale researches have been seen in China In this paper, the contents and pollution level of sixteen PAH compounds in surface soils in different types of soil utilization in Tianjin area were studied Results show that the highest contents of PAHs could be found in soils in urban areas The contents of a few compounds in soils irrigated with wastewater were also relatively high, but most compounds show similar contents compared with other types of soils such as the general cropland and unused land The ratio of low circle PAHs / high circle PAHs and the ratio of pyrene / benzo\pyrene have been used to identify the sources of PAHs pollution Among the six kinds of soils, the ratios of low circle PAHs / high circle PAHs for five kinds of soils were lower than 1, except for urban soils This has demonstrated that the PAHs pollution in Tianjin soils were mainly caused by the burning of fossil fuels The ratio of pyrene / benzo\pyrene shows that the high contents of PAHs in urban soils were mainly caused by pollution of transportation A Dutch Soil Remediation Standard was applied for assessing the pollution situation of the soils in Tianjin area Results show that all surface soils have been polluted in a certain extent by some compounds of PAHs Among the different soil types, the urban soils suffered the most serious pollution