石家庄市滹沱河冲洪积扇地下水中BHT和TEP的污染水平及风险评价

为了解华北平原地下水的有机污染状况,在石家庄市滹沱河冲洪积扇采集44个地下水水样,测定了被广泛应用的抗老剂BHT(2,6-二叔丁基对甲酚)和增塑剂TEP(磷酸三乙酯)的污染水平,分析了其分布受水文地质的影响及其对人体健康的风险.结果表明,ρ(BHT)在ND(低于检出限)～7.158 μg/L之间,中位值为0.010 μg/L,检出率为98%；ρ(TEP)在ND～5.081 μg/L之间,中位值为0.177 μg/L,检出率为70%.地下水的水文特性(如导水性、富水性和渗透系数)影响BHT和TEP的分布,二者在导水性、富水性较好和渗透性差的滹沱河冲洪积扇中部浅层孔隙水单元的质量浓度较高,分别为0.001～7.158和ND～3.604 μg/L.石家庄市滹沱河冲洪积扇地下水中ρ(BHT)和ρ(TEP)均低于国外报道值,但检出率高于国外报道值,其中11%的地下水水样中ρ(TEP)高于OECD(经济合作与发展组织)规定的饮用水风险特征阈值(2.4 μg/L).研究显示,石家庄市滹沱河冲洪积扇地区来自于地表的化工产品已淋溶到地下,并对该地区地下水造成了污染. 

Pollution Levels and Risk Assessment of BHT and TEP in Groundwater in Alluvial-Pluvial Fan of Hutuo River,Shijiazhuang City

Abstract:In order to investigate the contamination level of organic pollution in groundwater from the alluvial-pluvial fan of Hutuo River in Shijiazhuang City,44 groundwater samples were collected and analyzed.The results showed that butylatedhydroxytoluene(BHT),which is widely used for anti-aging,was detected in 98% of samples,with the concentrations ranging from ND to 7.158 μg/L and the median value 0.010 μg/L.Trithylphosphate(TEP),used as fire-retarding plasticizers,could be detected in 70% of samples.The concentrations of TEP ranged from ND to 5.081 μg/L,with the median value 0.177 μg/L.High hydraulic conductivity,good water-abundance and poor permeability,which were the hydrologic characteristics of groundwater in the shallow pore water unit located in the middle alluvial-pluvial fan of Hutuo River,lead to higher levels of BHT and TEP(0.001-7.158 μg/L and ND-3.604 μg/L,respectively).The concentrations of BHT and TEP were lower than those in previous foreign studies with higher detection rates.11% of groundwater samples showed higher concentrations of TEP than the threshold (2.4 μg/L) for drinking water recommended by the Organization for Economic Cooperation and Development(OECD).The current study indicated that the chemical products had leached into the ground,and caused pollution of groundwater in the region of alluvial-pluvial fan of Hutuo River.