Occurrence and distribution of PPCPs in water from two largest urban lakes of China: First perspective from DGT in-situ measurement.

Pharmaceutical and personal care products (PPCPs) are an important group of emerging contaminants that may threaten organisms at trace concentrations. However, research on the occurrence of PPCPs in urban lakes in China is still scarce. In this study, 15 PPCPs in the Tangxun Lake and the Donghu Lake were collected using the diffusive gradients in thin-films (DGT) technique and analyzed by high performance liquid chromatography tandem-mass spectrometry (HPLC-MS/MS). Thirteen of the 15 targeted PPCPs were detected in the Tangxun Lake, and all PPCPs were detected in the Donghu Lake, with total concentrations ranging from 160 to 730 ng/L (average: 401 ng/L) and 187 to 1933 ng/L (average: 653 ng/L), respectively. Bisphenol A (BPA) was the dominant PPCP, followed by disinfectants in both lakes. The total concentrations of PPCPs in the Donghu Lake were higher than those in the Tangxun Lake. The spatial distribution characteristics of PPCPs in the two lakes were different, with higher total concentrations in the eastern part than in the western part of the Tangxun Lake spatially and higher in the north-western part than in the south-eastern part of the Donghu Lake. The results of the risk assessment showed that BPA and estrone posed high risks to the aquatic environment (RQ ≥ 1), while triclosan and estriol presented a medium risk (0.1 ≤ RQ < 1) in some sites. This study was the first attempt to apply DGT for providing vital data on the evaluation of the ecological risk of PPCPs in the two largest lakes in China, and attention should be paid to the long-term ecological effects caused by the occurrence of PPCPs in lakes.

Distribution, sources and transport of polycyclic aromatic hydrocarbons (PAHs) in karst spring systems from Western Hubei, Central China.

Karst groundwater is an important water resource but it is vulnerable to contaminants, due to the distinctive geological features of abundant transmissive fractures and conduits in the karst area which connect the surface to the underground systems. Anthropogenic activity-derived polycyclic aromatic hydrocarbons (PAHs) on the surface environment could enter groundwater easily and rapidly and threaten water security in karst areas. Samples in the multimedia environment from 10 specific karst spring systems from Western Hubei of Central China were collected to analyze 16 priority PAHs and to investigate their transport in these karst spring systems. The total concentrations of PAHs in the soil, river water, river sediments, spring water, and spring sediments ranged between 6.04 and 67.7 ng g-1, 4.56 and 11.4 ng L-1, 29.9 and 1041 ng g-1, 4.09 and 222 ng L-1, and 5.88 and 83.0 ng g-1, respectively. Levels of PAHs in this area were relatively low when compared to other karst areas. Proportions of low-molecular-weight (LMW)-PAHs in the water, sediments and soil (average 58.2-78.8%) were much higher than those of high-molecular-weight (HMW)-PAHs. The proportion of LMW-PAHs in the sediments (especially in river sediments) was higher than that in the soil. Characteristic ratio analysis and principal component analysis showed that PAHs were from high-temperature combustion of the mixture of coal and biomass, and vehicle emission, where coal and biomass combustion were the dominant sources. Significant correlations of PAH compositions in different media of karst spring systems were observed, especially in the Yuquangdong (YQD)-Migongquan (MGQ), Jiuzhenziquan (JZZQ), Xianyudong (XYD) and Fengdong (FD) karst spring systems, indicating the rapid PAH transport from the recharge area soil to the discharge area of spring water and sediments.