Thesis (M. Sc.)--University of Hong Kong, 200.

No description available.

No description available.

The measurement of ambient particulate concentration (PM10 and PM2.5) using active monitors requires expensive or labour-intensive apparatus or both. Although PM is a priority pollutant, this has precluded widespread or intensive ambient particulate monitoring networks to be set up in South Africa, except in some priority areas. In this study, locally manufactured passive PM monitoring devices (samplers), based on a design initially published by researchers at the University of North Carolina (UNC), were calibrated for the measurement of PM10-2.5. Duplicate samplers of each type (local and UNC) were co-located at eight reference stations equipped with TEOM (Tapered element oscillating microbalance) or BAM (Beta radiation attenuation monitor) particulate monitors in three networks. Imaging of the substrate was carried out using an optical microscope to limit the cost of analysis. The images (10 to 49 per sample) were analysed using both proprietary (Zeiss AxioVision®) and open-source (ImageJ) software at 100X and 200X magnification. Considerable variation exists between the four co-located local and UNC samplers at all stations, although the latter show lesser discrepancies when analysed using the AxioVision software. Greater agreement of the local samplers and the continuous monitors is noted at a 200X and 100X magnification using the AxioVision software with R2 = 0.81 and R2 = 0.79 respectively. The precision of PM10-2.5 measured with the passive samplers was highly variable with calculated CVs ranging from 10.4% to 73.3%. 82% of the CVs were less than 40%. The average CV for all samplers was 34.6%. Passive samplers analysed using the AxioVision software recorded smaller average discrepancies of 45.3% at 100X and 37.3% at 200X magnification. Samplers analysed using ImageJ at 100X magnification exhibited the highest percentage difference from the reference values (81.2%). Using a two factor ANOVA we can show that (at 95% confidence) the analysis software and the imaging magnification have the most significant effect on the calculated sampler concentration results. A disadvantage of passive samplers is large number of days (2-7) required to produce statistically significant values hence disqualifying it for use as a reference method. The device is, therefore, more suitable for screening-level, high spatial density sampling, but some non-regulatory applications are pointed out. / Dissertation (MEng)--University of Pretoria, 2019. / Chemical Engineering / MEng (Environmental Engineering) / Unrestricted

No description available.

No description available.

No description available.

No description available.

Urban air quality management is a system for governments to lead cities towards achieving good air quality standards in an efficient way. Good air quality can avoid many environmental issues which are regarding air problems. At least, reduce environmental impacts efficiently in some extent. Carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2), volatile organic compounds (VOC) and particulate matter (PM) are the common elements of air pollution. Topography, weather, the physical and chemical properties of pollutants and emission sources are also accomplices of air pollution. Östersund was a case study in this thesis because it has satisfactory air quality and won the European Mobility Week Award in 2014. Weather, winds, transportation and heating systems are the factors that influence urban air quality in Östersund. Green Traffic, Green Energy, and Green Highway are efficient projects in connection with air quality improvement in Östersund. Through successful technical application and institutional management, Östersund became one of the best climate cities in Sweden. This study is main focus on how Östersund municipality manages the local urban air quality then tries to find the suitable parts for China to learn. Here learn means find the suitable ways to improve urban air quality in China. It doesn’t mean copy all these projects. Emissions from vehicles, dust and the old style structures of energy are the main factors to reduce urban air quality in China. China did similar projects like Östersund did to improve urban air quality but the results were not so distinct so far. Vast land and large population are significant characteristics in China which make China’s ability slow to solve the air problem. Controlling the dust and emission from vehicles, using renewable resources and clean energy, optimizing industrial structure and complete legislations are beneficial projects to improve urban air quality in China. The projects of Green Traffic and Green Highway, and public participations are significant parts in Östersund which worth to learn for Chinese cities.

Thesis (Ph.D.) -- McMaster University, 1999. / Includes bibliographical references (p. 144-149). Also available via World Wide Web.