嘉陵江重庆段表层水体多环芳烃的污染特征

为了确定嘉陵江重庆段表层水体中多环芳烃(PAHs)的组成、来源及污染特征,于2009年8月采集了8个表层水样,利用GC-MS仪器测定了16种优先控制PAHs的浓度.结果表明,水体中16种优先控制PAHs浓度范围为467.13～987.97ng.L-1,平均浓度值为702.91 ng.L-1,水体PAHs浓度和溶解性有机碳(DOC)含量呈现明显的线性正相关.PAHs的组成以2～3环PAHs为主,占水体ΣPAHs总量的68.90%.寸滩区域水体PAHs主要来源于木材和煤的燃烧污染,朝天门区域水体PAHs主要来源于石油源,嘉陵江重庆段其他区域水体PAHs主要来源于液体石化燃料的燃烧.虽然嘉陵江重庆段整体污染水平较低,但是5个取样点的地表水苯并(a)芘(BaP)含量超过国家地表水质量标准.

Contamination Characteristics of Polycyclic Aromatic Hydrocarbons (PAHs) in Surface Water from Jialing River in Chongqing

To understand the composition,sources and contamination characteristics of PAHs in surface water from Jialing River in Chongqing,water samples were collected from 8 different sections in August 2009 and the concentrations of the 16 priority PAHs were determined using GC-MS.The results indicated that the concentration of PAHs(the total PAHs) in the water body ranged from 467.13 to 987.97 ng·L-1,with an average concentration of 702.91 ng·L-1.PAHs concentrations in surface waters were positively correlated with the dissolved organic carbon content.The predominant PAHs in the water body were 2-3 ring PAHs,accounting for 68.90% of PAHs.The ratios of specific PAHs revealed that the main PAHs source in Cuntan was the combustion of wood and coal,the origin of PAHs in Caotianmen was mostly petrogenic;whereas the main PAHs source in other sampling sections of Jialing River in Chongqing was petroleum combustion.Compared with other areas in China,the PAHs contamination in Jialing River around Chongqing was at a relatively low level,however,the concentrations of BaP in the surface water of 5 sampling sites exceeded the environmental quality standards for surface water in China.