[Inventory and Distribution Characteristics of Anthropogenic Ammonia Emissions in Zhejiang Province from 2008 to 2018].

As ammonia is the main component of PM2.5, long time series of ammonia emission characteristics are an important basis for studying the historical causes of PM2.5 pollution. In this study, the activity data of various anthropogenic ammonia emissions from 11 cities were collected in Zhejiang. The anthropogenic ammonia emissions inventory in Zhejiang was established using emission factors, and then a 1 km×1 km spatial grid distribution was carried out using ArcGIS software. The results showed that from 2008 to 2018, the ammonia emissions from anthropogenic sources in Zhejiang exhibited a downward trend, with an average annual decline rate of approximately 3.97%. The ammonia emissions were 108.52 kt in 2018, and the emission intensity was 1.03 t·km-2, in which there was 90.02 kt from agricultural sources and 18.50 kt from non-agricultural sources. The ammonia emissions of Hangzhou, Jiaxing, and Wenzhou were higher than those of the other cities, accounting for 14.72%, 11.86%, and 11.80% of the total ammonia emissions, respectively. The spatial distribution characteristics showed that ammonia emissions were mainly distributed in the northern part of Zhejiang, showing an emission trend of "high in the north and low in the south." Uncertainty analysis showed that the simulated average value of ammonia emissions was 108.37 kt, and the uncertainty range in the 95% confidence interval was -5.40%-5.60%.

[Long-range transport potential of typical organic pollutants in Nanjing].

In this study, the long-range transport potentials (LRTP) of typical organic pollutants including p,p'-DDT, gamma-HCH, BaP and HCB in air and water of Nanjing were estimated using the TaPL3 model. The research results showed that the characteristic travel distances (CTD) of BaP and p,p'-DDT through air were relatively low, 198 km and 255 km, respectively, indicating relatively low LRTP and difficulty in pollution dispersion. In contrast, gamma-HCH and HCB tended to transport over longer distances through water and air, with CTD values of 91 558 km and 19 056 km in water and 1 858 km and 21 104 km in air, respectively, indicating that the dispersion of pollution in air and water of the studied area was relatively easy. Furthermore, the stickiness of gamma-HCH and HCB in water was negative, and the values were -2.1 and -54.86, respectively, indicating that gamma-HCH and HCB tended to remain in the atmosphere. The mass fractions in air after they passed air and achieved the steady state were 0.551% and 2.2%, respectively, whereas the mass fractions in air after they passed water and achieved the steady state were 0. 149% and 1.05% , respectively, which were higher than those of p,p'-DDT and BaP.