摘要
城市化及汽车的发展导致城市大气中多环芳烃(PAHs)含量较高,强致癌作用污染物苯并(a)芘(BaP)含量也相应增高。植物是大气环境天然的过滤器,能滞留、吸附和累积空气中多种污染物。选择广州市8种常见行道树,4种乔木:红花羊蹄甲(Bauhinia blakeana)、腊肠树(Cassia fistula)、高山榕(Ficus altissima)、白兰(Michelia alha)和4种灌木:福建茶(Carmona microphylla)、灰莉(Fagraea ceilanica)、黄金榕(Ficus microcarpa)、九里香(Murraya exotica),分析植物叶片中BaP和∑PAH16在春、夏、秋三季的含量,并与大气中的浓度进行比较。结果表明:植物叶片对大气中BaP的吸收量最高为59.91 ng/g,BaP的吸收量占∑PAH16吸收的0.05%～8.29%。5环颗粒态BaP主要是通过叶片吸收进入植物体内,和植物高度、叶片质地等相关性不大,主要取决于叶茎转运等内在机制。建议以绝对吸收量(ng/g)来选择行道树种。高山榕、黄金榕和九里香可做为较好的绿化树种。
Polycyclic aromatic hydrocarbons （PAHs） in the urban air was highly caused by rapid urbanization and automobile development ,and Benzo（a） pyrene （BaP） also increased accordingly. Plants were natural air filters, could retard and absorb and accumulate all kinds of pollutants in the atmosphere. Four arbors： Bauhinia blakeana, Cassia fistula, Ficus altissima, Michelia alha and four shrubs ： Carmona microphylla, Fagraea ceilanica, Ficus microcarpa, Murraya exotica were chosen to analyze the BaP and ~ PAH16 contents in their leaves in spring, summer and autume, and compared with the corresponding concentrations in air. The results showed that the highest contents of the leaf absorption of Bap was 59.91 rig/g; the absorption percentage of BaP was 0.05% - 8.29% in total ~ PAH16; the correlative coefficient r was 0. 539 between the average contents of BaP in three seasons with the BaP concentrations in the air. Particulate BaP with 5 rings was absorbed into the plants chiefly by their leaf absoption and with no close correlation with the heights or the leaf quatity of plants, maybe depended on the transfer mechanism from their leaf to stem. Absolute absorbtion （ng/g） was suggested to be used for street tree selection. Ficus altissima, Ficus microcarpa, Murraya exotica were recognized to be good street trees in Guangzhou.
出处
《城市环境与城市生态》
CAS
CSCD
2011年第4期5-8,共4页
Urban Environment & Urban Ecology
基金
"广东省环境污染控制与修复技术重点实验室开放研究基金"资助项目(2006K0009)
