浑河沿岸污灌区地下水中PAHs分布特征研究

在浑河沿岸沈抚、浑蒲污灌区采集23个地下水样,采用固相萃取-气相色谱/氢火焰检测器(SPE-GC/FID)方法,对美国环境保护局(USEPA)优先控制的16种多环芳烃(PAHs)进行定量分析.结果表明,该区域地下水受到PAHs严重污染,苯并a]蒽(BaA)、苯并k]荧蒽(BkF)检出率分别为100%和82.6%.土壤剖面研究结果表明,BaA和BkF在土壤中的垂直分布比较均匀,显示其在土壤中具有很强的迁移能力.研究发现其原因在于BaA和BkF的沉积物-水分配系数(Koc)较大,其对数值lg Koc分别为5.30和5.74,在土壤-地下水粗分散系统中,容易吸附于大颗粒胶体有机质上,形成悬浮液、乳浊液或者泡沫等,并在布朗运动力推动之下发生迁移.

Study on Distribution of PAHs in Groundwater in Irrigation Area along the Hunhe River in Liaoning Province

Twenty-three groundwater samples were collected from Shenfu and Hunpu irrigation areas along the Hunhe River,and sixteen polycyclic aromatic hydrocarbons(PAHs) listed as priority pollutants by the US EPA were analyzed quantitatively by the method of solid phase extraction-GC/FID.The results indicated that the concentration of PAHs detected in the area was very high.The detectable rate of BaA and BkF reached 100% and 82.6% respectively.According to the soil profile analysis,the mobility of BaA and BkF was very strong in view of the even vertical distribution.It could been concluded that colloidal matter inherent in the subsurface might provide a favorable phase for PAHs partitioning and the coefficient(lg K_(oc)) of BaA and BkF was(5.30) and(5.74) respectively,so they were easy to form suspend liquor,emulsion and spume when they adhered to the coarse colloid in the disperse system.