Main findings Although the data did not allow the inclusion of non-identified or “unknown” sources, allocation of the impact at the receptor point to the identified sources proved possible and useful in comparing individual tailings dams contributions. The No. 4 tailings dam has been identified as one of the major contributors to PM10 concentration at West Village. The average PM10 gravimetric concentration recorded at West Village was 18.4 μg/m3 and the concentration with the light scatter method was 15.4 μg/m3. Black carbon has been identified as significant contributor to overall PM10 mass concentrations with up to 34% in the winter season. Source appointment from receptor-based measurements has not been previously conducted at Driefontein Gold Mine. Source apportionment can make a valuable contribution in attempts to reduce air pollution. At a site where particulate matter is the predominant pollutant from a variety of potential sources, the contributions from the individual sources may be difficult to distinguish especially if the sources fall within a single category type with similar pollutant profiles. It would be useful to ascertain the individual contributions so that the effectiveness of existing control measures can be determined and areas where additional controls may be required can be identified. Too this effect, potential dust sources at and around a gold mine were identified. Samples of the dust sources were collected and analysed for their elemental compositions and abundances. A receptor point in a mine village was selected and equipped with an ESampler PM10 dust monitor as well as an aethalometer, the MicroAeth AE51 (MicroAeth). Monthly receptor samples were collected and analysed for their elemental concentrations. The elemental compositions of the potential sources and the concentrations at the receptor were statistically analysed for 12 periods of a month each to determine the possible contributions to the PM10 concentration at a mine village (West Village, Driefontein Mine, near Carletonville). Main conclusions Operational tailings dams can under, certain conditions contribute the major portion of fallout dust and PM10, even more than dormant tailings dams. / Dissertation (MSc)--University of Pretoria, 2013. / gm2014 / Chemical Engineering / Unrestricted

The aim of the project was to study the mineral, chemical and morphological characteristics of the fallout dust samples. The dust fallout samples were collected at five different sites following the internationally accepted standard procedure for collection and analysis, South African National Standard and American Standard for Testing Methods (ASTM) D1739-98 (2010). Passive single buckets containing ¾ of distilled water and 10.0 ml of sodium hypochlorite (NaOCl) solution, hoisted at a height of about 2.5 m were exposed from March – June 2013 and were collected every month, taken to the laboratory for characterization. First, the samples were filtered and mass concentrations per month were gravimetrically measured. The samples were then prepared for further characterization by the MicroScan Particle Analyser (MSPA)(Microscope UOP UB 100j) which measured the mineral content and the Scanning Electron Microscope - Energy Dispersive X- ray (SEM - EDX) measured the images of different particles (size, shape) and their elemental content. The results from the MicroScan analysis showed the prevalence of sandy rounded-shaped quartz (SiO2) particles across all sites. Minerals detected within the crustal material at all sites were quartz (SiO2), haematite (Fe; Fe2O3; Al2O3), feldspar (Na, K, Mg, Ca: AI2Si2O8), garnet (SiO4), aluminium silicates (AI2Si2O8) and calcium hydroxide [Ca (OH)2]. Evidently, sites A, B and C dominated the abundance of these minerals. On the other hand, sites D and E showed fine and rounded quartz and quartzite with various trace metal oxides. Measured elements in decreasing concentrations were Si, Ca, P, Al, K, S, Fe, Cu, Ti and Mg. Both coarse particle (2.5 - 10.0 μm) and fine particle sizes ranges (< 1.0 to 2.5 μm) were detected. Large irregular shaped particles sizes were common and were linked to crustal material. The results provide good baseline information which requires further characterization of samples by different analytical techniques and validation of possible sources. The ICP-MS was used to determine the elemental composition of dust fallout and the mean concentration of the elements of concern ranged from 1.1 - 2.6 for As, 0.2 - 0.6 for Cd, 17.0 - 21.9 for Ni, 449.8 - 751.1 for Pb, 9.9 - 22.3 for V and 101.7 - 293.0 μg/m3 for Zn. The elements such as Cd exceeded the set limit 0.005 μg/m3 by OSHA (2015) and NIOSH (2007); Pb exceeded the set standard of 0.5 μg/m3 set by OSHA (2015), NIOSH (2007), WHO (2000), USEPA (2012) and DEA (2013). The rest of the elements fell within the set guidelines by various regulatory national and international bodies. The study concludes that, although, all the sampling sites recorded the dust fallout rates within the SANS 1929 (2011) and DEA (2013) average RESIDENTIAL limit of 600 mg/m2/day, the future accumulation and exceedances cannot be ruled out owing to the increasing developments in urban areas / Environmental Sciences / M. Sc. (Environmental Science)