淮河中游重化工聚集区干流水体中多环芳烃研究

Study on PAHs from the Heavy Chemical Accumulation Area in the Main Stream of the Middle Reaches of Huaihe River

淮河是中国七大河流之一,在中国国民经济发展中具有举足轻重的地位。有机物污染是淮河的主要污染形式。多环芳烃(PAHs)是一种典型持久性有机污染物(POPs),在水中的浓度较低,易于被悬浮物和沉积物吸附。为探讨淮河中游重化工聚集区干流水体中多环芳烃的含量和分布情况,2007年10月在淮南和蚌埠段采集悬浮物样品和表层沉积物样品。所采集的环境样品经自然风干后,利用二氯甲烷提取,无水硫酸钠和固相萃取柱组合净化,采用气相色谱-质谱联用法(GC-MS)同时定性和定量检测其PAHs含量,获得了美国EPA优先表中所列的16种PAHs含量数据,在此基础上探讨了淮河中游重化工聚集区干流水体悬浮物和沉积物样品中PAHs的分布特征,并初步分析了蚌埠市饮水源区蚌埠闸处PAHs的超标情况。结果表明:①淮河中游重化工聚集区干流水体环境样品中PAHs总含量变化幅度较大,其悬浮物浓度范围为1169.44～4048.86ng/g,表层沉积物中浓度范围为91.98～1292.52ng/g;②就单一组分而言,悬浮物中萘含量最高,表层沉积物中二苯并[a,h]蒽最高;③受采样点环境和PAHs本身性质影响,悬浮物中PAHs量远大于其沉积物中量,整体呈现悬浮物中以低环PAHs为主、沉积物中以高环PAHs为主的特征;④根据《国家海洋沉积物质量标准》,蚌埠闸沉积物中PAHs超标严重,对蚌埠市的饮水安全产生一定的威胁,同时,此处悬浮物中PAHs含量也很高,潜在危害性更大,应给予重视。

As one of the seven major rivers in China, Huaihe River is of great importance in the national economy, in which organic contaminations become a major issue.Polycyclic Aromatic Hydrocarbons（PAHs） are typical examples of Persistent Organic Pollutants（POPs）.PAHs are very low in water and easy to be adsorbed by suspended substances and sediments.To study the concentrations and distributions of PAHs in the heavy chemical accumulation area in the main stream of the middle reaches of Huaihe River, suspended substance and surface sediment samples from the section of Huainan and Bengbu were collected in October 2007.By naturally air-drying, the environment samples were extracted with dichloromethane.Then the samples were cleaned up by sodium sulfate coupled with the columns of solid phase extraction.Finally the samples were measured qualitatively and quantitatively by Gas Chromatography/Mass Spectrometry.The data for 16 PAHs in the prior table listed by American EPA were obtained.On its basis, the features of the PAHs distribution in the heavy chemical accumulation area in the main stream of the middle reaches of Huaihe River were studied, especially, the PAHs contents in Sluice Bengbu, which were found to be above the standard in a preliminary study.The results may be summarized as follows.（1） The levels of the studied PAHs are high, from 1 169.44 to 4 048.86 ng·g-1 in suspended substances, and 91.98 to 1 292.52 ng·g-1 in sediments.（2） As single components, Naphthalene is up in suspended substances, while Dibenzo a, h anthracene is in sediments.（3） Due to the effects of sampling sites and PAHs itself, the concentrations of PAHs in suspended substances are significantly higher than those in sediments.Meanwhile, globally, the low-ring PAHs prevail over high-ring PAHs in suspended substances, while high-ring PAHs prevail in sediments.（4） According to the quality standard of national ocean sediments, the contents of PAHs in sediments from Sluice Bengbu are seriously overweight.It poses a great danger to the safety of drinking water in Bengbu, as the more PAHs in suspended substances, the greater potential danger will be.