多溴联苯醚在电子废弃物拆卸地沉积物中的垂直分布

采用气相色谱质谱联用仪对采自清远电子废弃物拆卸地水库钻孔沉积物中的多溴联苯(polybrominated diphenyl ethers,PBDEs)进行了分析,调查其在沉积物中的垂直分布.结果表明,PBDEs在所有的样品中均检出,含量为0.43～141 ng/g,平均为9.26 ng/g.PBDEs在下层(16 cm以下)沉积物中含量较低、变化很小(0.43～2.30 ng/g),但在上层沉积物中含量明显增加(2.90～141 ng/g),反映了当地电子废弃物拆卸活动的影响;3种工业源的PBDEs,即五溴、八溴和十溴PBDEs,表现出相似的垂向分布趋势,说明其来源的一致性.其中,十溴PBDEs是最主要的PBDEs,平均占所有PBDEs的79.6%,其次是五溴PBDEs(14.7%),而八溴PBDEs所占比例最低(5.69%).3种PBDEs的组成模式显示,它们与相应的工业品PBDEs组成都有一定差异,可能因其降解行为不同所致.一些PBDE的同族体组成在沉积钻孔的垂直变化也进一步说明高溴代PBDE在沉积物的埋藏期间可能发生了降解,虽然还需要进一步研究证实.

Vertical Profile of Polybrominated Diphenyl Ethers (PBDEs) in Sediment from an E-waste Area in South China

Polybrominated diphenyl ethers (PBDEs) were determined in a sediment core collected from a reservoir in an electronic waste (e-waste) area of South China. PBDEs were detected throughout the core,with a mean value of 9.26 ng/g dry weight. 0.43 to 141 ng/g PBDEs concentrations were low (0.43-2.30 ng/g) and varied less in the lower layers (below 16 cm) of the core,whereas their concentrations increased remarkably in the upper layers (2.90-141 ng/g). The vertical distribution of PBDEs indicated the influence of local e-waste recycling activities. PBDEs originated from commercial deca-BDE mixture were the dominant congeners,accounting for 79.6% of the total PBDEs,followed by PBDEs from penta-BDEs (14.7%). PBDEs from octa-BDEs contributed only 5.69%. The difference between PBDE congener profiles in the sediment and those in the commercial penta-,octa-,and deca-BDEs suggests the possible degradation of highly brominated PBDEs in the sediment,which was further supported by the occurrence of BDE202 and the vertical variation of the fractions of nona-BDE congeners and ratios of BDE197/BDE201. However,more work is needed regarding PBDE degradation in the environment.