Institute of Applied Radiation of Shanghai, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China.
Institute of Applied Radiation of Shanghai, School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, PR China.
Chemosphere. 2014 Sep;111:304-11. doi: 10.1016/j.chemosphere.2014.04.031. Epub 2014 May 13.
The concentrations, spatial distribution, diastereoisomer-specific profiles of hexabromocyclododecanes (HBCDs) in surface sediments from three major rivers in Shanghai as well as the seasonal variation of HBCDs were investigated. The concentrations of total HBCD diastereoisomers ranged from 0.05 to 6.87ngg(-1)dw. Significant spatial distribution of total HBCDs concentrations were observed. The mean concentration of total HBCDs followed the order of Suzhou Creek (2.00ngg(-1))>Huangpu River (1.59ngg(-1))>Yunzao Creek (0.77ngg(-1)). The concentration was a relatively low HBCDs level compared to levels measured in domestic and other parts of the world. The proportions of α-HBCD in sediment samples were generally higher than that of commercial formulations. This might be due to thermal isomerization from γ-HBCD to α-HBCD and slower degradation rate of α-HBCD compared to γ-HBCD in anaerobic conditions. The concentrations of ΣHBCD in the summer were significantly higher than those in the winter (paired t test, p<0.01). This seasonal variation could probably be attributed to a combined effect of temperature and wet deposition. Moreover, a poor and no significant correlation between ΣHBCD levels and TOC content in sediments was observed, suggesting that the spatial distributions of HBCDs were not constrained by the TOC in sediments of Shanghai.
研究了上海三大河流表层沉积物中六溴环十二烷（HBCDs）的浓度、空间分布、非对映异构体特征分布以及 HBCDs 的季节性变化。总 HBCD 非对映异构体的浓度范围为 0.05 至 6.87ngg(-1)dw。观察到总 HBCDs 浓度存在显著的空间分布。总 HBCDs 的平均浓度顺序为苏州河（2.00ngg(-1))>黄浦江（1.59ngg(-1))>蕴藻浜（0.77ngg(-1))。与国内和世界其他地区测量的水平相比，该浓度属于 HBCDs 浓度较低的水平。沉积物样品中α-HBCD 的比例通常高于商业配方中的比例。这可能是由于γ-HBCD 向α-HBCD 的热异构化以及在厌氧条件下α-HBCD 比γ-HBCD 降解速度较慢所致。夏季ΣHBCD 的浓度明显高于冬季（配对 t 检验，p<0.01）。这种季节性变化可能归因于温度和湿沉降的综合影响。此外，ΣHBCD 水平与沉积物中 TOC 含量之间观察到较差且无显著相关性，表明 HBCDs 的空间分布不受上海沉积物中 TOC 的限制。
