珠江虎门潮汐水道水体中多环芳烃的分布及季节变化

Distribution and seasonal changes of polycyclic aromatic hydrocarbons (PAHs) in surface water from Humen tidal channel

采用GF/F玻璃滤膜对珠江虎门潮汐水道6个表层水样进行过滤分离出多环芳烃的颗粒相和溶解相,并根据美国EPA标准对多环芳烃进行了定量分析.结果显示,洪、枯季水体中16种优先控制多环芳烃总量分别是223～614,6559～20031ng/dm3;洪、枯季多环芳烃总量分别为786～2098,11360～34338ng/dm3;广州前航道的污染较狮子洋严重.珠江虎门潮汐水道水体中多环芳烃的含量、分布具有明显的季节变化特征,枯季多环芳烃的浓度高于洪季1个数量级以上,且二环多环芳烃的含量占95%以上,主要呈溶解相形式出现;洪季高环多环芳烃的含量明显升高,主要呈颗粒相形式输运.

Six surface water samples from the Humen tidal channel were collected in 2001 and filtered by GF/F glass fiber filter. Polycyclic aromatic hydrocarbons (PAHs), including parent, alkylated and sulfur/oxygenated PAHs were identified and measured based on USEPA 8000 series methods and under quality assurance and quality control (QA/QC). The spatial and temporal distribution of particulate and dissolved PAHs during both low flow and high flow seasons was investigated. Total PAHs concentrations vary from 11 360 to 34 338 ng/dm^3 and 786～2 098 ng/dm^3 in low flow season and high flow season respectively, and the 16 PAHs concetrations vary from 6 559 to 20 031 ng/dm^3 and 223 to (614 ng/dm^3) in low flow season and high flow season respectively. The dominated compounds are 2-ring PAHs, which are up to 95% and exist mainly in dissolved phase in low flow season. PAH concentrations in low flow season are one order of magnitude higher than those in high flow season. The increase of high molecular weight PAHs and elevated concentrations of particulate phase PAHs were found in the high flow season.