Research On Predictive Control Method Of Indoor Particulate Pollution Based On Source Apportionment

There are significant correlations between particulate matter and human respiratory system,cardiovascular and cerebrovascular diseases,premature death,etc.according to the a large number of epidemiology and toxicology research.The particulate matter is regarded by the international organizations like World Health Organization(WHO),the US Environmental Protection Agency(USEPA)and European Union(EU)as the representative of atmospheric pollutant in the health hazard assessments of air pollution.According to the practical experience of air pollution treatment in developed countries,the treatment of atmospheric particulate pollution has lots of difficulties,long cycle and slow effect due to the particulate matter of wide source and complex ingredients,and it is difficult to achieve remarkable results soon.People spend more than 80% of time indoors,it has important scientific research and practical value to strengthen the prediction and control of indoor particulate pollution.The prediction and control of indoor particulate pollution involves many subjects such as aerodynamic,atmospheric science,engineering and technology,civil engineering and medicine,etc.The domestic research started late,and mainly focuses on the control target of PM10 or PM2.5 mass or number concentration,lacking of systematic research in indoor prediction and control theory and method.The control mechanism and its influencing factors were comprehensively analyzed from the particulate matter concentration,size,physical and chemical characteristics,and a predictive control method of indoor particulate pollution based on source apportionment was put forwarded.Through the theoretical and the experimental study,the dynamic behavior regularity into the indoor process was studied,the mechanism of the penetrating and deposition at different stages of transportation was revealed,the the control processes effects on the microstructure and chemical composition of the particles were also analyzed.A dynamic predictive control model of indoor particulate matter pollution based on source analysis was established,and its applicability was analyzed by practical engineering application.The main research contents in this paper included:(1)Actuality investigation and influencing factors analysis of indoor particle pollution.The factors that affect the concentration of indoor and outdoor particulate pollution were analyzed through sampling investigation on the characteristics of indoor and outdoor particulate pollution.The results showed that there were significant differences in the particulate pollution between indoor and outdoor.Moreover,the outdoor particulate pollution in Beijing had obvious seasonal characteristics,the diameter of the main particulate pollution was more than 5.0?m in heating season,however,it was between 2.5 ~ 5.0?m in summer.The diameter of the indoor particle was less than 0.5?m in the whole year.The results indicated that the characteristics of the indoor particle pollution could be influenced by several factors,such as,the structure of the building envelope,outdoor weather conditions,ventilation systems and air conditioning systems and indoor personnel activities.The analysis of the synchronous detection data of revealed that there was a significant correlation between indoor and outdoor particle pollution,and the correlation coefficient decreased with the increase of the particle size.The correlation analysis of segmented particles,which reflects the characteristics of indoor particle pollution,was better than that of cumulative particles.(2)Physicochemical characteristics analysis based on source apportionmentThe physical and chemical characteristics and the influence factors of indoor and outdoor particles were analyzed through High Electron Microscopy and Energy Dispersive Spectroscopy.The results showed that the particle size of the irregular mineral particles were easy to deposit in the ventilation ducts or be trapped,while small spherical particles,oval or spherical particles and soot aggregates were more easy to penetrate into the room through building structure crack and result in indoor pollution.There was a big difference in microstructure of indoor and the outdoor particles,the indoor particle sphericity was closer to 1.The mass percentage of mineral particles in which were rich in C,Al and O elements decreased in the building.However,mass percentage of particles i.e.sodium salt,potassium salt,and particles which were rich in Ti,Zn,Ba,increased.Compared with outdoor particles,indoor particles specific surface area was larger,therefore,indoor particles were more harmful to human health.(3)Indoor particulate matter predictive control method and model based on the source appointment.A predictive control method of indoor particulate pollution based on particle source apportionment was proposed,through indoor and outdoor particle pollution characteristics analysis,physical and chemical characteristics and dynamic behavior study,the mechanism of the influence of control process on mass concentration,particle size distribution and physical and chemical characteristics of indoor and outdoor particles was revealed.According to the theoretical analysis of aerodynamics,multiphase hydrodynamics,physical and mechanical properties of particles,and the experimental study of envelope gap and filters penetration,it was found that there was a specific law in coefficient of particle penetrating coefficient and the velocity,therefore,the predictive control model of indoor particle was established based on source appointment.According to the data analysis of indoor and outdoor the particulate pollution in a natural ventilation building,the model had a good prediction on indoor PM<0.5?PM0.5~1.0?PM1.0~2.5 mass concentration,compared with the measured values,the errors were 12.17%,13% and 6.19%,respectively.The model is applicable for practical engineering.