| National 12th Five-year Plan has determined regional economic integration of the Beijing-Tianjin-Hebei region as one of the national development strategy. In recent years, air pollution problem has already caused extensive concern of experts and scholars, due to the heavily populated and intensive industrial district. "Smog" weather happened frequent in autumn and winter Beijing-Tianjin-Hebei region; PM2.5 levels have exceeded the criteria many times, caused a lot of inconvenience to people’s life. Air quality index is high and the air is getting lower visibility constantly, while the PM25 is becoming important research objects of experts and scholars. SO2, NOX, and PM10 have been confirmed as a precursor of PM25 that made by sulfates and nitrates which are the main factors affecting the visibility. To research the cause of the atmospheric pollution in the Beijing-Tianjin-Hebei region and improve the regional air pollution status quality, this paper establishes a dynamic multi-media fugacity model to simulate the different forms of sulfur (SO2 and SO42-) in the transition and transform in multi-medium environment, selecting the sulfur as the research object. At the same time through interval arithmetic of the uncertainty analysis method combined with dynamic level IV dynamic fugacity model, building the uncertain interval dynamic medium fugacity model, and by solving the model to explore the different sulfur forms in the research area of environmental behavior and fate.In this study, it has made full analysis of sulfur in the environment in the process of the study area, conceded the morphological changes of sulfur in the same medium and cross media transmission occurs, and puts forward the assumption conditions according to the actual environment, constructs the multi-medium equal fugacity model. The specific data of sulfur in the ambient medium is obtained by the Euler algorithm to solve the model. The results showed that, quality change of sulfur in the multi-media environment from 1998 to 2005 has been increasing, showing predicted values and measured values coincide well, the logarithmic residual of SO2 in the atmosphere and SO42- in the atmosphere, water, soil, sediment medium were 0.14 and 0.15,0.92,0.02,0.02 respectively. At the beginning of the 2005, the quality of sulfur in soils and sediments gradually stable, but has declining trend in the atmospheric and water medium. The predicted results are in good agreement with the measured results, but the results in general larger. In the study area, sulfur mainly in the atmosphere and water source emission form into the multi-media environment, in the atmospheric phase advection and degradation. Distribution of sulfate is relatively uniform, in the four phases are stable existence environment. Migration of sulfur in the medium of the transformation between the trends is obvious, especially between the atmosphere and soil behaved significantly quality exchange, however, in atmosphere with water junction phase, the former make more delivery quality to the latter.The interval algorithm is introduced with the reaction module of multimedia fugacity model, to solve the simulation uncertainty arises, can eliminate parameter generation volatility influence on the results. At the same time, through the interval logarithm average residual simulation results show deviations, the obtained log residual range between forecast value were less than 0.2 and the actual value, it illustrate the uncertainty of simulation process while eliminating the interval dynamic fugacity model in multimedia environmental behavior of simulated pollutants. Through the sensitivity analysis of parameters such as temperature, depth, area of concentration has a significant effect on soil, sediments of medium sulfur, including the impact of different forms of sulfur octanol-water partition coefficient of the simulated results showed most significant, which descripted these parameters has the prominent function on the sulfur activity of fate in the environment. |
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