Assessment on the distribution and partitioning characteristics of polycyclic aromatic hydrocarbons (PAHs) in Lake Baiyangdian, a shallow freshwater lake in China

The characteristics of polycyclic aromatic hydrocarbons (PAHs) in water, suspended particulate matter (SPM), sediments, and hydrophytes from Lake Baiyangdian, a shallow freshwater lake in China were studied. The low-molecular-weight PAHs (2-3 ring PAHs) predominated (61.2 to 84.5%) in all samples. Principal component analysis (PCA) of individual PAHs and the ratios of selected PAHs showed that the PAHs in the lake were mainly petrogenic inputs. The solid-liquid distribution coefficient (K-d) in the water phase was much higher than the bioconcentration factor (BCF), and the leaf concentration factor (LCF) was higher than the root concentration factor (RCF) and stem concentration factor (SCF) in plant-sediment phase. Good linear log/log relationships were observed between the equilibrium partitioning coefficient (K-oc) and the octanol-water partitioning coefficient (K-ow), between RCF and K-ow, and between LCF and the octanol-air partitioning coefficient (K-oa). These results indicated that PAHs accumulated more easily in SPM than in submerged aquatic plants, and some low-molecular-weight PAHs could accumulate and be translocated in the lake's media. Media characteristics, contamination sources, and physicochemical properties all affect the partitioning of PAHs among water, SPM, sediments, and hydrophytes.