[Uncertainty analysis of ecological risk assessment caused by heavy-metals deposition from MSWI emission].

The CALPUFF model was applied to simulate the ground-level atmospheric concentrations of Pb and Cd from municipal solid waste incineration (MSWI) plants, and the soil concentration model was used to estimate soil concentration increments after atmospheric deposition based on Monte Carlo simulation, then ecological risk assessment was conducted by the potential ecological risk index method. The results showed that the largest atmospheric concentrations of Pb and Cd were 5.59 x 109-3) microg x m(-3) and 5.57 x 10(-4) microg x m(-3), respectively, while the maxima of soil concentration incremental medium of Pb and Cd were 2.26 mg x kg(-1) and 0.21 mg x kg(-1), respectively; High risk areas were located next to the incinerators, Cd contributed the most to the ecological risk, and Pb was basically free of pollution risk; Higher ecological hazard level was predicted at the most polluted point in urban areas with a 55.30% probability, while in rural areas, the most polluted point was assessed to moderate ecological hazard level with a 72.92% probability. In addition, sensitivity analysis of calculation parameters in the soil concentration model was conducted, which showed the simulated results of urban and rural area were most sensitive to soil mix depth and dry deposition rate, respectively.

[Characteristic analysis of a multi-day pollution event in Chang-Zhu-Tan Metropolitan Area during October 2013].

Chang-Zhu-Tan Metropolitan Area experienced a typical multi-day pollution event in October 2013. Based on the air pollution index, conventional pollutants observations, surface meteorological observations and sounding data, the relationships of air pollution, large-scale circumfluence and boundary layer meteorology of this event were comprehensively analyzed. Additionally, the sources and transport paths of pollutions were investigated by application of satellite remote sensing data and HYSPLIT4 model. The results showed that pollutants gradually accumulated in the earlier stage of the event (October 21th to 26th) , while in the later stage (October 27th to 31th) the characteristic pollutants of crop residue burning (PM2.5, CO, NO2) sharply increased. The deterioration of air quality in the later stage was mainly related to the remote transport of pollutants caused by straw burning. Analysis of simulations of HYSPLIT4 model and fire spots showed that the currents mainly came from Anhui and Hubei Province in the earlier stage, while in the later stage they were mainly from Jiangxi Province where fire spots were intensively located. Stable atmospheric stratification caused by steady uniform high-pressure field and slight wind due to the confrontation of cold and warm currents greatly contributed to the development, maintainability and reinforcement of the pollution event. The remote transport of pollutants had a significant impact on ambient air quality of Chang-Zhu-Tan Metropolitan Area.