漳卫南运河地表水中溶解态多环芳烃的污染特征、风险评价与来源辨析

研究了漳卫南运河流域地表水中USEPA16种优先控制的多环芳烃(PAHs)的分布特征和污染来源,2008年4月、10月水中PAHs总量分别在31.7～74.5ng.L-1、45.3～99.0ng.L-1之间,与国内外其他河流相比,整体处于较低污染水平.四女寺污染最严重;河口污染最轻.整体上看,10月份PAHs浓度比4月份略有增加.从16种多环芳烃单体的组成来看,漳卫南运河PAHs以2环、3环、4环为主.本研究提出了新的∑PAHs生态风险评价方法,结果表明,4、10两个月份最高风险商值(RQ∑PAHs(MPCs))均为0,最低风险商值(RQ∑PAHs(NCs))值分别在34.7～111.0、20.4～88.8之间,平均值分别为58.4、49.8.∑PAHs在7个采样点均呈现低生态风险,且4月份生态风险略高于10月份,风险最高值出现在4月份的四女寺,最低值出现在10月份的河口.源解析结果显示,漳卫南运河流域PAHs的含量和分布主要受煤炭及薪柴燃烧的影响,四女寺和河口地区受到一定的石油污染的影响.

Pollution characteristics,ecological risk assessment and sources of polycyclic aromatic hydrocarbons (PAHs) in surface water from the Zhangweinan River

The distribution and sources of 16 priority polycyelic aromatic hydrocarbons (PAHs) in surface water from the Zhangweinan River were investigated in this study. The total concentrations of PAHs ranged from 31.7 to 74.5 ng·L~(-1) in April 2008 with an average value of 56.3 ng· L~(-1), and from 45.3 to 99.0 ng·L~(-1) in October 2008 with an average value of 62.9 ng·L~(-1), which is lower than the PAH concentrations in other rivers in the world. The spatial distribution of PAHs showed that Sin si was a heavily polluted site and the estuary was slightly polluted compared to other sampling sites. The temporal distribution showed that concentrations of PAHs in October were higher than those in April. The PAHs were dominated by 2-, 3-, 4-ring components in water samples in April (25.1% ,48.7% and 19.1%) and October (29.9% ,45.5% and 22.9%). A new ecological risk assessment method was introduced in this study. The values of RQ _(∑PAHs(MPCs)) at all sites were 0 and the values of RQ_( ∑PAHs(NCs)) ranged from 34.7 to 111.0 in April with a mean value of 58.4 and from 20.4 to 88.8 in October with a mean value of 49.8. The levels of ecological risk were generally low, and the risk in April was slightly higher than that in October. The ecological risk was the highest at Sinitsi in April and was the lowest at the estuary in October. The molecular indices and isomer pair ratios were used to infer the sources of PAHs, and the results suggest that anthropogenic heavy fuel combustion is the main source. At Sinusi and the estuary, petroleum made a large contribution to PAH pollution.