洋浦湾表层海水中多环芳烃的分布特征及来源分析

Distribution and Sources of Polycyclic Aromatic Hydrocarbons(PAHs)in Surface Seawater from Coastal Areas of the Yangpu Bay

以海南洋浦湾海域的8个位点为监测对象,采用固相萃取法富集,超高效液相色谱（UPLC）测定表层海水中14种多环芳烃（PAHs）的含量,研究了PAHs的不同季节时空分布特征以及污染来源,并与国内外其他河口及海湾海水中PAHs质量浓度进行了比较。结果表明：洋浦湾海域水体中受到了一定程度的多环芳烃污染,14种PAHs总质量浓度范围为426.52~1 006.30 ng/L,平均总质量浓度为569.95 ng/L,其中萘的浓度最大,占PAHs总量的59.8%。2~5环PAHs分别占总浓度的59.8%、18.4%、20.6%、1.2%,5环在部分采样点中未有检出,6环均未检出。该海域PAHs含量具有明显的季节分布特征,冬季（均值690.70 ng/L）和春季（均值625.66 ng/L）PAHs含量明显高于秋季（均值481.94 ng/L）和夏季（均值481.51 ng/L）,其中冬季各样点平均含量最高。旱季水体中PAHs质量浓度明显高于雨季。工业码头和港口PAHs浓度低于渡口、渔港等生活区。采用同分异构体比值法进行污染来源分析,表明春、夏、秋季洋浦湾表层水中PAHs主要来源于石油污染;冬季生活区主要为高温燃烧和石油的混合源,工业区则主要来自石油源。

Temporal and spatial distributions,pollution source of PAHs in different seasons were studied in surface seawater from 8 typical sampling sites in Yangpu coastal areas. Comparison of concentrations of PAHs in the surface water from various estuary and coastal regions were made,and 14 parent PAHs were qualified by solid phase extraction and ultrahighpressure liquid chromatography（UPLC）with fluorescent detection. Results showed that total PAHs concentration in surface seawater was ranged from 426.52 to 1 006.30 ng/L with the mean value of 569.95 ng/L,and naphthalene（2 rings） was dominant among PAH compounds with percentage of 59.8%. As for PAHs composition,percentage of 2 ~5 ring PAHs was59.8%,18.4%,20.6%,1.2% respectively.5 rings was not detected in some sites,6 rings was not detected in all sites. Clearly seasonal trends were observed in this study,with average concentrations of PAHs in winter（690.70 ng/L） and spring（625.66 ng/L）higher than that of in autumn（481.94 ng/L）and summer（481.51 ng/L）.Average concentrations of PAHs were the highest in winter and lowest in summer except Site 2. In dry season average total concentration of PAHs was higher than that of in wet season. PAHs concentration in fishing port and living quarters were higher than in the industrial wharves and port. The ratios of B [a]A/（B [a]A＋Chr）and Flua/Pyr suggested that petroleum-derived contamination may be the dominant source of PAHs in the surface seawater in spring,summer and autumn;in winter,PAHs in living quarters may be derived from both pyrogenic and petrogenic sources,while petroleum input of PAHs in industrial zone.