白洋淀典型持久性有机污染物污染特征与风险评估

Occurrence and Ecological Risk Assessment of Typical Persistent Organic Pollutants in Baiyangdian Lake

对白洋淀表层水体和表层沉积物中多环芳烃(PAHs)、有机氯农药(OCPs)和多溴联苯醚(PBDEs)三类典型持久性有机污染物(POPs)的污染特征进行综合调查和分析.结果表明:(1)白洋淀水体中PAHs、OCPs和PBDEs浓度范围分别是71.32~228.27、2.62~6.13和0~6.5 ng·L^(-1);沉积物中PAHs、OCPs和PBDEs含量范围分别是163.20~861.43 ng·g^(-1)、2.25~6.07 ng·g^(-1)和230.96~1 224.13 pg·g^(-1).与历史数据相比,白洋淀沉积物PAHs和OCPs含量均有明显下降;与国内外湖泊相比,白洋淀沉积物中PBDEs含量处于较低水平.(2)水体和沉积物PAHs污染来自于油类排放和木材、煤炭燃烧的共同作用;白洋淀水体和沉积物中OCPs组成均以HCHs为主(93.76%和63.10%),水体中HCHs主要来源于工业HCHs的降解,部分地区来源于大气的远距离传输和林丹的使用,DDTs则主要来源于历史残留.沉积物中HCHs主要来源于新的林丹使用,也有少量工业HCHs的输入,DDTs则以历史残留为主,可能部分地区存在新的DDTs输入;白洋淀水体中PBDEs组成以BDE-2为主(65.80%),可能主要来源于大气远距离传输和高溴代联苯醚的降解,沉积物中PBDEs组成以BDE-209为主(63.82%),主要来源为商用的十溴联苯醚.(3)生态风险评价结果表明,白洋淀尚无明显生态风险,但部分采样点存在生态风险的可能性,应加强监控.

A comprehensive survey of the pollution characteristics of persistent organic pollutants（ POPs） in the surface water and surface sediment of Baiyangdian Lake was carried out. The survey showed that：（1） The concentrations of the polycyclic aromatic hydrocarbons（ PAHs）,organic chlorine pesticides（ OCPs）,and polybrominated diphenyl ethers（ PBDEs） in the surface water of Baiyangdian Lake were 71. 32-228. 27 ng·L^-1,2. 62-6. 13 ng·L^-1,and 0-6. 5 ng·L^-1,respectively,and those in the surface sediment were 163. 20-861. 43 ng·g^-1,2. 25-6. 07 ng·g^-1,and 230. 96-1224. 13 pg·g^-1,respectively. On comparison with historical data,the concentrations of PAHs and OCPs in both the surface water and surface sediment were found to be decreasing,while compared with the domestic and foreign lakes,the concentration of PBDEs in the surface sediment was at a low level.（2） The main source of PAHs,both in the surface water and surface sediment in Baiyangdian Lake,originated from fuel discharge and combustion sources. HCHs compose the main part of OCPs in both the surface water（ 93. 76%） and surface sediment（ 63. 10%）. In the surface water body,HCHs mainly originated from the degradation of industrial HCHs; in some sites HCHs originated from atmospheric longdistance transmission and the usage of Lindane,while DDTs originated from historical residues. In surface sediment,HCHs mainly originated from the usage of new Lindane,with little industrial HCHs,and DDTs mainly originated from historical residues,while new DDTs may have been used in some sites. BDE-2（ 65. 80%） composed the main part of PBEDs in the surface water,and it mainly originated from atmospheric long-distance transmission and degradation of high brominated diphenyl ethers; BDE-209（ 63. 82%）constituted the main part of PBDEs in the surface sediment,and it mainly originated from the commercial Deca-BDEs.（3） EcologicalRisk Assessment show that there was no obvious ecological risks in Baiyangdian Lake,but in some sites POPs may cause ecological risks; these sites should be monitored more frequently.