[Distribution Characteristics of Per-/polyflouralkyl Substances in River Sediments Around Typical Fluorine Industrial Parks].

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are a group of manmade chemicals and are ubiquitously detected in aquatic environments. China is a major producer and consumer of PFASs. In this study, we investigated the occurrence and characteristics of PFASs in the surface sediments from three fluorine industrial parks in North China, the Xihe River in Liaoning Province (Fuxin Section), the Xiaoqing River in Shandong Province (Zibo Section), and the Yangtze River in Jiangsu Province (Changshu Section), using the UPLC/MS-MS method. The total concentration of PFASs (∑PFASs) in surface sediments of the Xihe River ranged from 15.8 to 2770 ng ·g-1, and PFTeDA and HFPO-DA were the dominant pollutants. In the surface sediments of the Xiaoqing River, ∑PFASs ranged from 12.2 to 7853 ng ·g-1, and PFOA and HFPO-DA were the dominant pollutants. In the surface sediments of the Yangtze river, ∑PFASs ranged from 9.20 to 35.9 ng ·g-1, and PFTeDA and 6：2 FTS were the main pollutants. Sewage discharge from the industrial parks (point source pollution) was the main source of PFASs in three regions in this study. The PFAS content and composition in three regions varied significantly depending on the production capacity and industry type. There was no significant correlation between the content of PFASs and its components and the particle size and TOC of the sediments. The correlations between the components of PFASs indicated that the enrichment process of PFASs in sediments was impacted by various factors.

[Distribution and Seasonal Variations of Chromophoric Dissolved Organic Matter(CDOM) in the Bohai Sea and the North Yellow Sea].

UV-Vis spectral data and a fluorescence excitation-emission matrix (EEM) was analyzed for the surface, middle, and bottom layer water samples from the Bohai Sea and North Yellow Sea in April, August, and December of 2016 and February of 2017. Distribution characteristics, influencing factors, and seasonal variation of CDOM in the study area were investigated. The results showed that the horizontal distributions of CDOM are similar in different seasons, showing a characteristic of high levels near shore and low levels in the offshore region. Strong correlations were observed between value a (355) and spectral slope S275-295, indicating that CDOM is significantly affected by land input. According to the vertical distribution, the CDOM level is the lowest in surface seawater in summer due to strong photo-degradation. In February, controlled by primary productivity, the lowest level of CDOM was found in the bottom seawater. From April 2016 to February 2017, the content of CDOM first increased and then decreased. Its concentration was highest in December. Seasonal variations are mainly controlled by land input and on-site production. According to analysis of the spectral slope S275-295, the average molecular weight of CDOM in winter was smallest in February, which was mainly related to the drastic reduction of land-based input at that time. The strong photo-degradation in summer resulted in a small average molecular weight of CDOM.

Radiocarbon-based source apportionment of carbonaceous aerosols at a regional background site on Hainan Island, South China.

To assign fossil and nonfossil contributions to carbonaceous particles, radiocarbon ((14)C) measurements were performed on organic carbon (OC), elemental carbon (EC), and water-insoluble OC (WINSOC) of aerosol samples from a regional background site in South China under different seasonal conditions. The average contributions of fossil sources to EC, OC and WINSOC were 38 ± 11%, 19 ± 10%, and 17 ± 10%, respectively, indicating generally a dominance of nonfossil emissions. A higher contribution from fossil sources to EC (∼51%) and OC (∼30%) was observed for air-masses transported from Southeast China in fall, associated with large fossil-fuel combustion and vehicle emissions in highly urbanized regions of China. In contrast, an increase of the nonfossil contribution by 5-10% was observed during the periods with enhanced open biomass-burning activities in Southeast Asia or Southeast China. A modified EC tracer method was used to estimate the secondary organic carbon from fossil emissions by determining (14)C-derived fossil WINSOC and fossil EC. This approach indicates a dominating secondary component (70 ± 7%) of fossil OC. Furthermore, contributions of biogenic and biomass-burning emissions to contemporary OC were estimated to be 56 ± 16% and 44 ± 14%, respectively.

[Concentrations and distribution of organochlorine pesticides in the surface sediments of Jiaozhou Bay, Taozi Bay and Sishili Bay].

Forty-eight surface sediment samples collected from Jiaozhou Bay, Taozi Bay and Sishili Bay were analyzed for organochlorine pesticides (OCPs) by Gas Chromatography. Results showed that average concentrations of HCHs, HCB and DDTs in marine sediments were 0.33, 0.31 and 10.33 ng x g(-1) in Jiaozhou Bay and 0.26, 0.10 and 4.56 ng x g(-1) in Taozi Bay and Sishili Bay, respectively. Contamination status of OCPs was relatively higher in Jiaozhou Bay than in other inland coastal regions, especially for the levels of DDTs; however, OCPs concentrations were relatively low in Taozi Bay and Sishili Bay. The source of HCHs could be mainly attributed to the heavy historical application in agricultural areas and late transport to coastal region through surface runoff or riverine discharge, and DDTs were primarily originated from the use of technical DDTs. Fresh input of lindane and dicofol-type DDTs were found in several sites, such as Qingdao Port. High concentrations of DDTs in Jiaozhou Bay should arouse much attention.

Impact of anthropogenic emissions and open biomass burning on regional carbonaceous aerosols in South China.

Carbonaceous aerosols were studied at three background sites in south and southwest China. Hok Tsui in Hong Kong had the highest concentrations of carbonaceous aerosols (OC=8.7±4.5µg/m(3), EC=2.5±1.9µg/m(3)) among the three sites, and Jianfeng Mountains in Hainan Island (OC=5.8±2.6µg/m(3), EC=0.8±0.4µg/m(3)) and Tengchong mountain over the east edge of the Tibetan Plateau (OC=4.8±4.0µg/m(3), EC=0.5±0.4µg/m(3)) showed similar concentration levels. Distinct seasonal patterns with higher concentrations during the winter, and lower concentrations during the summertime were observed, which may be caused by the changes of the regional emissions, and monsoon effects. The industrial and vehicular emissions in East, Southeast and South China, and the regional open biomass burning in the Indo-Myanmar region of Asia were probably the two major potential sources for carbonaceous matters in this region.