Mass Concentration Of Suspended Particulate Matter Research Articles

Patterns of suspended particulate matter across the continental margin in the Canadian Beaufort Sea during summer

Abstract. The particulate beam attenuation coefficient at 660 nm, cp(660), was measured in conjunction with properties of suspended particle assemblages in August 2009 within the Canadian Beaufort Sea continental margin, a region heavily influenced by freshwater and sediment discharge from the Mackenzie River, but also by sea ice melt. The mass concentration of suspended particulate matter (SPM) ranged from 0.04 to 140 g m−3, its composition varied from mineral to organic dominated, and the median particle diameter determined over the range 0.7–120 µm varied from 0.78 to 9.45 µm, with the fraction of particles <1 µm in surface waters reflecting the degree influenced by river water. Despite this range in particle characteristics, a strong relationship between SPM and cp(660) was found and used to determine SPM distributions across the shelf based on measurements of cp(660) taken during summer seasons of 2004, 2008, and 2009. SPM spatial patterns on the stratified shelf reflected the vertically sheared two-layer estuarine circulation and SPM sources (i.e., fluvial inputs, bottom resuspension, and biological productivity). Along-shelf winds generated lateral Ekman flows, isopycnal movements, and upwelling or downwelling at the shelf break. Cross-shelf transects measured during three summers illustrate how sea ice meltwater affects river plume extent, while the presence of meltwater on the shelf was associated with enhanced near-bottom SPM during return flow of upwelled Pacific-origin water. SPM decreased sharply past the shelf break with further transport of particulate matter occurring near the bottom and in interleaving nepheloid layers. These findings expand our knowledge of particle distributions in the Beaufort Sea controlled by river discharge, sea ice, and wind, each of which is sensitive to weather and climate variations.

Correlation between inorganic pollutants in the suspended particulate matter (SPM) and fine particulate matter (PM2.5) collected from industrial and residential areas in Greater Cairo, Egypt

Simultaneous sampling collection of suspended particulate matter (SPM) and fine aerosol particles with an aerodynamic diameter equal or less than 2.5 μm (PM2.5) from industrial and residential areas of Greater Cairo, Egypt, has been carried out during two different seasons namely autumn 2014 and winter 2014/2015. The average mass concentrations of both SPM and PM2.5 samples are higher than the annual mean levels, especially for the samples collected from the industrial area. In addition, the mass concentrations of SPM are much higher than the PM2.5 mass concentrations during the whole sampling period. The ratios of the mass concentration between the SPM and PM2.5 were determined to be equal to 20 ± 6 and 17 ± 4 for the residential and industrial areas, respectively, and these ratios seem to be constant during the two mentioned seasons. Based on our previous elemental analysis results using multiple secondary target energy dispersive X-ray fluorescence (EDXRF), 18 elements in both SPM and PM2.5 samples have been quantified. Remarkable variations in the elemental concentrations between the SPM and PM2.5 samples were obtained. Comparison and statistical analysis of the elemental composition of both SPM and PM2.5 have been investigated. The PMF model EPA 5.0 was utilized for source identification on both PM fractions. Seven sources were identified and their relative contributions in the two areas of the study were investigated.

Distribution and cross-front transport of suspended particulate matter over the inner shelf of the East China Sea

An obvious shear front between the Taiwan Warm Current and the Zhe–Min (Zhejiang–Fujian) Coastal Current exists over the inner shelf of the East China Sea (ECS) in winter. Although the cross-front spread of surface water in the ECS has been reported based on satellite images, the cross-front transport of suspended particulate matter (SPM) has not been well studied. To reveal the detailed characteristics of SPM in vertical direction, in terms of different fractions, and to study its cross-front transport and mechanism, high-vertical resolution profiles of SPM concentrations observed by Laser In-Situ Scattering and Transmissometry (LISST) and derived from water samples at various levels, together with salinity and temperature, were measured in February 2007, from 34 stations in the ECS. Results showed that volume concentration (VC) of SPM finer than 280.07µm has a good correlation with mass concentration (MC), because coarser factions were thought to be biological components. The VC was then converted to the MC of different fractions at high resolution, by reducing the influence of biological sources. Both temperature and salinity data showed an obvious front along 50m-isobath in the bottom layer, tilting seaward toward the surface layer. Within 50m-isobath, the MC was higher than 2mg/L in the surface layer and 10mg/L in the bottom layer. The SPM could be transported across the front to the sea in the bottom layer, even to the east of 100m-isobath, where the MC of SPM was less than 1mg/L in the surface layer and 2mg/L in the bottom layer. The SPM across the front was mainly silt fraction with some fraction of clay. An idealized numerical model was established. Numerical experiment results showed that bottom Ekman transport produced by the northerly wind in winter is the key factor controlling cross-front transport, and strong northerly wind is responsible for its expansion. This study helps our understanding of material exchange in the coastal and shelf seas.

SEASONAL VARIATION AND THEIR CHARACTERIZATION OF SUSPENDED PARTICULATE MATTER IN THE AIR OF SUBWAY STATIONS

In order to accumulate fundamental data on the atmospheric environments in subway, the mass concentration, particle size distribution and elemental constitution of suspended particulate matter (SPM), and the concentration and constitution of polycyclic aromatic hydrocarbon (PAH), were measured and analyzed at three subway stations with different air supply systems on the same line. The mass concentration of SPM in the subway stations showed seasonal variations, and was higher in December and October than in March and June. It was also higher at the subway stations than in the aboveground throughout the seasons. The concentrations of SPM in the size range of 0.5–5.0 μm were higher in the subway stations than aboveground, suggesting this size of SPM was generated by the operation of trains. The elements that were observed at high concentrations in the subway SPM were Fe, Ba, Cu and Ca. On the other hand, the elements of which concentrations were relatively higher in the aboveground air were Cl, Na and K. Polycylic aromatic hydrocarbons collected at the subway stations showed similar concentrations and characteristics to those observed in the urban atmosphere.