Two sampling sites representing the urban and suburban area of Chengdu, China were sampled and analyzed for selected chemicals to characterize the evolution of the chemical composition of fogwater. A trend of total organic carbon (TOC) > total nitrogen (TN) > total inorganic carbon (TIC) was observed for both sites. Variation of inorganic ions indicated that inorganic pollutants were not accumulated in the fog. Concentrations of n-alkanes (C11-C37) at the urban site ranged from 7.58 to 27.75 ng/mL while at the suburban site concentrations were 2.57-21.55 ng/mL. The highest concentration of n-alkanes was observed in the mature period of fog (393.12 ng/mL) which was more than ten times that in the fog formation period (27.83 ng/mL) and the fog dissipation period (14.87 ng/mL). Concentrations of Σ15PAHs were in the range of 7.27-38.52 ng/mL at the urban site and 2.59-22.69 ng/mL at the suburban site. Contents of PAHs in the mature period of fog (27.15 ng/mL) > fog dissipation period (11.59 ng/mL) > fog formation period (6.42 ng/mL). Concentrations of dicarboxylic acids (C5-C9) ranged from 10.92 to 40.78 ng/mL, with glutaric acid (C5) as the dominant dicarboxylic acid. These data provide strong indications of the accumulation of certain organic chemicals of environmental concern in fog and fog water, and provide additional insights about processes in urban and suburban air acting on organic chemicals with similar physical chemical properties. 相似文献
This paper discusses the effect of network infrastructure on environmental pollution reduction and the realization mechanism behind it. Based on the panel data of 285 cities in China from 2005 to 2019, this study regards the “Broadband China” pilot policy as a quasi-natural experiment to clarify the pollution emission reduction effect of network infrastructure construction through differences-in-differences method and other methods. The research results show the following: (1) The Broadband China pilot policy has reduced environmental pollution, that is, the construction of network infrastructure has the effect of environmental pollution reduction. The conclusion is still established after a series of robustness tests such as parallel trend test, placebo test, and instrumental variable method. Through the heterogeneity test, it is found that the pollution reduction effect of network infrastructure construction is more obvious in non-resource-based cities, first and second tier cities, and cities in the eastern region (2). The construction of network infrastructure plays a restraining role on local environmental pollution. Due to the insufficient level of regional linkage and the siphon effect of pilot cities, the spatial spillover characteristics of the pollution reduction effect are not obvious (3). The mechanism of action shows that green innovation is an important mediating effect mechanism for network infrastructure construction to reduce environmental pollution. Cities in regions with high degree of marketization and environmental regulation can strengthen the effect of network infrastructure construction on environmental pollution reduction. The research conclusions are conducive to accelerating the development of the digital economy represented by the construction of network infrastructure and provide a useful reference for promoting the level of environmental pollution reduction and achieving high-quality development.
