Sources Apportionment Of Air Dustfull Near Ground In Chengdu Urban

Air dust about 1.5～2.0 meters away from ground is a mixture of dustfall andflying dust, which has great influence upon people's health. It is significant forsynthetical prevention and cure the dustfall pollution in air enviroment of Chengduurban area, by applying source-analysis to do a qualitative and quantitative study onsources and contribution ratio to the air dust near ground.At present, a mathematics model is generally used as the receptor model to finishsource-analysis. There are over ten methods for receptor model, the chemical massbalance and factor analysis were commonly used.The results of fator analysis revealed that there were seven main sources of airdustfall near ground in Chengdu urban area: (1) construction dust, (2) smelt metal dust,(3)plant burning soot, (4)coal dust (containing soil dust), (5)traffic dust, (6) dyestuffand paint dust, (7)garbage dust.By using chemical mass balance method, the pollution sources of air dustfallnear ground are analyzed with 5 discharge sources. The average contribution ratio ofthe five pollution sources were as follows: 11.4% for soil dust, 12.4% for constructiondust, 5.8% for coal dust, 11.2% for smelt metal dust, 59.3% for city dust.When regarding people's daily life as the processes of producing toxic elements,we can use the theory of statistics process control to investigate the toxic elements inair dustfall near ground. Then, it could be used with the quality control model on thisproduce process. Therefore, the distributions and transformations of toxic elementscould be characterized and controlled for the synthetically air pollution provention inthe urban area. Actually, it was also a process of source-analysis to analyseconcentration variations of toxic elements and trace their sources using this model.This thesis illustrated in detail of the constrution of the quality-control model ofmercury. Additionally, it was confirmed that the theory of statistics process control onrestrain the toxic elements was feasible in air dustfall near ground.