清水泉岩溶地下水中多环芳烃污染特征及来源

Pollution characteristics and source analysis of PAHs in the karst groundwater of Qingshui Spring

为了确定南宁市清水泉岩溶地下水中多环芳烃的组成、来源及污染特征,沿该地下河上游、中游、下游布设5个采样点。经过采样送检,检测了16种优控多环芳烃（PAHs）。结果表明,丰水期地下水中ΣPAHs（PAHs总量）浓度为163.87~209.96ng/L,平均值为183.10ng/L,以2环和3环的PAHs物质（萘、菲和荧蒽）为主,约占总量的52%。丰水期、平水期和枯水期的清水泉地下水中,PAHs浓度整体上分布规律为：上游〈中游〈下游,浓度增大的主要原因是沿途污染源的不断汇入。地下水中2环和3环PAHs、4环PAHs、5环和6环PAHs、PAHs总量的季节性浓度变化整体上呈现出相同的变化规律,即枯水期〉平水期〉丰水期,这与PAHs的物理化学性质有关。PAHs来源分析表明,研究区下游地区PAHs来源为石油,中上游地区来自燃料的高温燃烧。与其他地区比较,清水泉地下水虽然出现了PAHs污染,但污染程度较低。

To determine the components,source,and pollution characteristics of Polycyclic Aromatic Hydrocarbons（PAHs）in the karst groundwater of Qingshui Spring,five sampling points were set along the upstream,midstream,and downstream of the river,and 16 priority PAHs were detected.The results showed that（1）the total PAHs concentration in the wet season is163.87~209.96ng/L with an average value of 183.10ng/L,and 2~3ring naphthalene,fluoranthene,phenanthrene account for 52% of the total PAHs;（2）the downstream of Qingshui Spring has the highest PAHs concentration in the dry,normal,and wet seasons,followed by the midstream,and the upstream has the lowest,which,is caused by the continually increased pollution source along the river;（3）the of 2~3ring PAHs,4ring PAHs,5~6ring PAHs,and total PAHs concentrations are the highest in the dry season and lowest in the wet season,which is related to the physicochemical properties of PAHs;and（4）the PAHs source is petroleum in the downstream and fuel combustion in the upper and middle streams.Compared to other regions,the PAHs pollution level of the karst groundwater in Qingshui Spring is low.