Adsorption of polycyclic aromatic hydrocarbons in seawater by mangrove leaf litter
- 生命科学－已发表论文 
在实验室条件下,研究了海水中多环芳烃(PAHs)(含低分子量PAHs苊、菲和屈艹以及高分子量PAHs苯并[g,h,i]芘)浓度分别为40、400和4000μg·L-1时,红树植物秋茄(Kandeliacandel)和白骨壤(Avicennia marina)不同分解状态落叶碎屑对PAHs的吸附作用。结果显示:在同等PAHs浓度下,秋茄和白骨壤落叶碎屑对4种PAHs的吸附总量相近,树种间或分解状态间的吸附差异不显著;随着PAHs浓度的增加,2种红树植物落叶碎屑对4种PAHs的吸附率均呈现逐渐增加的趋势;PAHs浓度较低时,落叶碎屑对艹屈和菲有较高的吸附率或选择性吸附,PAHs浓度较高时,落叶碎屑对苯并[g,h,i]芘吸附率提高。上述结果表明,不同分解状态下的红树植物落叶碎屑对海水中PAHs均有较强吸附能力,及时清除落叶碎屑,是去除海水中PAHs的有效途径之一。Under laboratory conditions, this paper studied the adsorption of different concentration (40, 400 and 4 000 μg·L-1) polycyclic aromatic hydrocarbons (PAHs) including low molecular weight acenaphthylene, phenathrene and chrysene and high molecular weight benzo[g,h,i]perylene in seawater by the leaf litters of Kandelia candel and Avicennia marina at different decomposition status. The results showed that at the same concentrations, the total amount of test PAHs adsorbed by the K. candel and A. marina leaf litters had no significant difference, in spite of their decomposition status. The adsorbed amount of the PAHs tended to increase with their increasing concentrations. The litters had a higher adsorption rate of or exhibited selective adsorption to phenathrene and chrysene when the PAHs concentrations were lower, and had a higher adsorption rate of benzo[g,h,i]perylene when the PAHs concentrations were higher. These results indicated that mangrove leaf litter at different decomposition status had higher adsorption rates of PAHs in seawater. It is suggested that cleaning up the mangrove leaf litter in time could be one of the most effective ways to remove PAHs from seawater.