多环芳烃在城市湖泊气-水界面上的交换

Exchange of Polycyclic Aromatic Hydrocarbons (PAHs) Across Air Water Interface in Luhu Lake, Guangzhou

利用大流量采样器和半渗透膜装置对广州麓湖大气中气态多环芳烃和水体中溶解态多环芳烃进行了连续一年的观测,在此数据基础上,依据国内外通用的双膜理论计算了多环芳烃在广州麓湖水面上的交换通量.结果显示萘、苊、二氢苊的交换通量方向是由湖水挥发进入大气,其它主要化合物都是从大气进入水体;在单个化合物的交换通量中,以菲的通量值为最大,平均达13137.1ng/(m2·d),最高达到21211.22ng/(m2·d),其次为萘、荧蒽、蒽、芘、芴、二氢苊和苊等.各化合物交换通量的季节变化特点大部分都是在夏季达到最大值,在冬季交换通量降到最小值,但唯一例外的是芴,其交换通量却是在夏季降到最低值.

The gaseous phase PAHs in atmosphere and dissolved phase PAHs in water were sampled by high volume air sampler and semipeameiable membrane device (SPMD) in Luhu Lake, respectively. According to the stagnant two film model, the direction and magnitude of exchange fluxes of PAHs across air water interface in Luhu Lake were calculated based on above data. The result showed that most PAHs were absorbed from atmosphere to water except naphthelene, acenaphthylene, and acenaphthene, which fluxes direction, was from water to atmosphere. Phenanthrene has highest magnitude of exchange flux(21211.22ng/(m2·d)), and then naphthelene, fluoranthene, anthracene, pyrene, fluorene et al. the largest exchange flux of PAHs was calculated for summer except for fluorene, which largest exchange flux was in winter.