Characterisation of Airborne Particulate Matter in a City Environment

Abstract

<p class="MsoNormal" style="margin: 0cm 0cm 4pt; line-height: 12pt; mso-line-height-rule: exactly;"><span style="font-size: 10pt; mso-bidi-font-size: 11.0pt; mso-ansi-language: EN-GB; mso-bidi-font-weight: bold;" lang="EN-GB"><span style="font-family: Times New Roman;">Airborne particulate matter contains a mixture of pollutants.<span style="mso-spacerun: yes;"> </span>Identifying the source of these particles, their composition and physical/chemical properties would help to provide a clear connection between their impacts on the environment and the human health.<span style="mso-spacerun: yes;"> </span>Individual particles have a different chemical morphology and this data could provide information on the formation and reaction mechanism of these particles. It also helps to identify the source they originate from as well as their atmospheric history.<span style="mso-spacerun: yes;"> </span>Over the years, numerous studies have been conducted to characterise PM_10­ and little work has been carried out on PM_2.5.<span style="mso-spacerun: yes;"> </span>However, there is an emerging interest in identifying the effects of very fine particles such as nano-particles.<span style="mso-spacerun: yes;"> </span></span></span></p><p class="MsoNormal" style="margin: 0cm 0cm 4pt; line-height: 12pt; mso-line-height-rule: exactly;"><span style="font-size: 10pt; mso-bidi-font-size: 11.0pt; mso-ansi-language: EN-GB; mso-bidi-font-weight: bold;" lang="EN-GB"><span style="font-family: Times New Roman;">The main objective of this research project was to carry out a comprehensive characterisation study of nano-particles collected from a city environment.<span style="mso-spacerun: yes;"> </span>Environmental monitoring samples from a local authority monitoring site were collected over a period of 7 months using a tapered element oscillating microbalance technique (TEOM). T<span style="mso-bidi-font-style: italic;">he sample filters were then analysed for their morphology and elemental compositions using SEM/EDS and LA-ICP-MS.<span style="mso-spacerun: yes;"> </span></span>SEM/EDS analysis was able to detect several heavy metal particulate matter while the LA-ICP-MS showed that there were more heavy metals present in the filter samples especially the heavier metals.<span style="mso-spacerun: yes;"> </span>Some of these heavier elements could have been inhibited by organic or higher amounts of the more common metals found in the EDS such as Fe, Zn, Si and Al.<span style="mso-spacerun: yes;"> </span>Nano-particles originated from high temperature sources, biological, carbonaceous and road transport were also detected in the samples.<span style="mso-spacerun: yes;"> </span>It was also found that particles containing more metallic elements tended to have a more defined shape while carbonaceous materials typically had amorphous structures. Tests showed that p<span style="mso-bidi-font-style: italic;">articles with environmental dust compositions of Ca, Al and Si were abundant.<span style="mso-spacerun: yes;"> ...

Experimental Investigation of Indoor Air Pollutants in Residential Buildings

“…This commonly arises from cooking activities. The EDS results obtained in this study are similar to those reported by other researchers [15]. Figure 9 presents the real-time concentrations of indoor CO in the kitchens of the city-centre flat (Case 2) and the urban flat on a main road (Case 3).…”

Characterisation of particulate matter on the receptor level in a city environment

“…In the early 1900s, coal burning for steel production and domestic heating was a major contributor to poor air quality which was associated with adverse health effects on the population (Daly and Elleker 2004). The introduction of the Clean Air Act in 1956 resulted in enforcement of a smokeless zone and improved air quality for residential as well as industrial areas (Chung et al 2008). Within the city boundary, the motorway was also a major concern for air pollution generation.…”

“…The particle from GH3 in Fig. 3i is an example of a bacterium or an environmental microorganism known as biofilm (Chung et al 2008). The surface texture of the particle displays similarities to the biofilm particles shown by Little et al (1991) The effect of EDS analysis on the particle surface can be seen in the middle of the particle, where it is smoother than the surrounding dotted surface.…”

“…The particle featured in the middle of Fig. 3b is a cenosphere (Chung et al 2008). These morphologies suggest that the particles could have been formed during high-temperature processes (Vallack and Chadwick 1993;Vassilev and Vassileva 1996) or coal-fired power stations about 60 km northeast of the city.…”

A Study of the Porosity of Activated Carbons Using the Scanning Electron Microscope

“…It thus offers enormous possibilities of shedding light on the pore development processes than hitherto known . Already, in areas such as materials engineering, biology and medical sciences, the SEM has been extensively used to study and characterize the microstructure of substances [Chira et al, 2009;Vaishali et al, 2008;Chung, et al, 2008;Kamran, 1997]. The purpose of this chapter is to discuss the potential use of the SEM in understanding porosity development in activated carbon and pore structure characterization using micrographs of coconut shells at different stages during the manufacture of coconut shell-based activated carbons.…”