Deng Hong-Mei, Chen Yong-Heng, Chang Xiang-Yang
School of Environmental Science and Engineering, Guangzhou University, Guangzhou 510006, China.
Huan Jing Ke Xue. 2009 Nov;30(11):3276-82.
To obtain the seasonal and vertical distribution and partition of PAHs between dissolved phase and particle phase in Xijiang River basin, water columns were collected during flood seasons (August, 2003 and July, 2004) and dry seasons (November, 2003 and Mar, 2004) from Gaoyao section of Xijiang River. The average PAHs concentrations in dissolved phase and particle phase were 21.7-138 ng x L(-1), 40.9-664.8 microg x kg(-1), respectively. Total PAHs concentrations (both particle phase and dissolved phase) were higher in flood seasons than that in dry seasons. No variation was found for dissolved PAHs in vertical distribution. However, a same trend of vertical distribution was observed for particle PAHs with the maximum concentration in middle layer and minimum in surface layer of water column. With increasing of content of suspended particle matter (SPM), both dissolved and particle PAHs concentration increased. In the dissolved phase, the predominant PAHs were 3 ring PAHs. While in the particle phase, 3-4 ring PAHs were the dominant PAHs. The partition coefficient (K(p)) had no correlation with the particle organic carbon content of SPM (R2 0.000 1-0.2), but influenced by concentrations of suspended particle matters and dissolved organic carbon, especially black carbon in dissolved phase (R2 0.15 -0.36). A majority of values of lg K(oc) in different seasons exceeded upper limit based on typical model of equilibrium distribution. Except the season of November 2003 (R2 0.000 4-0.12, p < 0.001), the organic carbon normalized distribution coefficients (K(oc)) computed for the PAHs were correlated well with their octanol-water partition coefficient (K(ow))(R2 0.29-0.91, p < 0.05). The lipophilic ability of SPM was stronger in flood seasons than that in dry seasons.
为获取西江流域多环芳烃（PAHs）在溶解相和颗粒相中的季节及垂直分布与分配情况，于2003年8月、2004年7月洪水期以及2003年11月、2004年3月枯水期，从西江高要断面采集水柱样本。溶解相和颗粒相中PAHs的平均浓度分别为21.7 - 138 ng·L⁻¹、40.9 - 664.8 μg·kg⁻¹。洪水期PAHs总浓度（颗粒相和溶解相之和）高于枯水期。溶解态PAHs的垂直分布无变化。然而，颗粒态PAHs呈现相同的垂直分布趋势，水柱中层浓度最高，表层最低。随着悬浮颗粒物（SPM）含量增加，溶解态和颗粒态PAHs浓度均升高。溶解相中，主要的PAHs为三环PAHs。而在颗粒相中，三环至四环PAHs是主要的PAHs。分配系数（Kp）与SPM的颗粒有机碳含量无相关性（R² 0.0001 - 0.2），但受悬浮颗粒物浓度和溶解有机碳影响，尤其是溶解相中的黑碳（R² 0.15 - 0.36）。不同季节多数lg Koc值超过基于典型平衡分布模型的上限。除2003年11月（R² 0.0004 - 0.12，p < 0.001）外，计算得到的PAHs有机碳归一化分配系数（Koc）与它们的正辛醇 - 水分配系数（Kow）相关性良好（R² 0.29 - 0.91，p < 0.05）。洪水期SPM的亲脂能力强于枯水期。
