Search results for "particulate"
showing 10 items of 295 documents
CFD modelling of flue gas particulates in a biomass fired stove with electrostatic precipitation
2013
Abstract The biomass fired stoves have been used in medium and large scales applications from several years and are utilizing electrostatic precipitator technology. Biomass based technologies are considered as renewable energy source and less harmful to the environment. The combustion of biomass generates a high concentration of flue gas particulates. The most of the flue gas particulates in the exhaust gas can be filtered through an electrostatic precipitator. In this work, a computational fluid dynamic (CFD) model has been developed for analysing the trajectory of particulates in a small scale domestic stove using biomass material. It is considered that electrostatic precipitator is based…
Analysis of a severe pollution episode in Valencia (Spain) and its effect on ground level particulate matter
2013
Abstract This study analyzes the atmospheric particles concentration at ground level during a severe pollution event that took place in Valencia (Spain) from 7 to 12 February 2011. The episode was related to a subtropical anticyclone system that affected the Iberian Peninsula and western Europe. The dominant anticyclone imposed an extended low gradient pressure system and a low mixing layer height in the region that caused the accumulation of pollutants over the western Mediterranean. Moreover, the stagnant conditions led to the formation of the local sea breeze, accompanied by an increase of relative humidity and the decrease of ambient temperature. Our study is mainly focused on the analy…
Global simulation of semivolatile organic compounds – development and evaluation of the MESSy submodel SVOC (v1.0)
2019
Abstract. The new submodel SVOC for the Modular Earth Submodel System (MESSy) was developed and applied within the ECHAM5/MESSy Atmospheric Chemistry (EMAC) model to simulate the atmospheric cycling and air–surface exchange processes of semivolatile organic pollutants. Our focus is on four polycyclic aromatic hydrocarbons (PAHs) of largely varying properties. Some new features in input and physics parameterizations of tracers were tested: emission seasonality, the size discretization of particulate-phase tracers, the application of poly-parameter linear free-energy relationships in gas–particle partitioning, and re-volatilization from land and sea surfaces. The results indicate that the pre…
Passive sampling of PAHs in indoor air in Nepal
1999
PAHs were sampled in ten homes in the Makwanpur region, Nepal. SPMDs and moss bags (Sphagnum girgensohnii) were used as passive samplers. Soot particles on the SPMD surfaces were also analyzed for PAHs. The overall PAH concentrations in SPMDs were significantly higher than those in moss bags. Total PAH mean concentrations of ten houses were 535μg/g lipid for SPMDs and 7.2 μg/g moss (dw) for moss bags. Ratios of phenanthrene/anthracene in indoor SPMDs and particulate matter varied from 2.9 to 3.5 and ratios of fluoranthene/pyrene varied from 1.1 to 1.4. The values for moss bags were respectively 1.7–3.6 and 0.8–2.4. These ratios indicate that the PAHs are from combustion origin. The PAH conc…
FTIR spectral analysis of PM10 and PM2.5 particulate matter over the urban area of Palermo (Italy) during normal days and Saharan events
2010
The principal sources of particulate matter in Palermo urban area are gasoline and diesel-powered vehicles, domestic heating, resuspension of soil dust and a geogenic source which includes soil erosion, marine aerosol and sporadic Saharan events. Annual average PM10 and PM2.5 concentrations result 27.8±9.8 and 21.3±5.1g/m3. The highest mass levels, 246 and 65 g/m3 respectively for PM10 and PM2.5, were observed during Saharan events. For the present study, which uses the ATR-FTIR spectroscopy to provide insights on the chemical composition of airborne particulate matter, a total of 89 filters were collected: 13 PM10 filters from a sub-urban background station, 36 PM10 and 40 PM2.5 filters …
Alteration effects of volcanic ash in seawater: Anomalous Y/Ho ratios in coastal waters of the Central Mediterranean sea
2007
This paper presents the results of a study based on data collected during the oceanographic cruise ANSIC 2001 carried out in the Ionian Sea during the explosive activity of Mount Etna in the summer of 2001. Anomalous low values of Y/Ho ratios in seawater suggest extensive scavenging processes on the surfaces of smectitic alteration products, with Y and Ho fractionation controlled by the differences in their electronic configurations and behaviour during solution/surface complexation equilibria. These processes can also be traced through the presence of significant tetrad effects recorded in the chondrite-normalised Rare Earth Elements and Yttrium (YREEs) patterns of suspended particulate ma…
Air pollution perception in ten countries during the COVID-19 pandemic.
2021
As largely documented in the literature, the stark restrictions enforced worldwide in 2020 to curb the COVID-19 pandemic also curtailed the production of air pollutants to some extent. This study investigates the perception of the air pollution as assessed by individuals located in ten countries: Australia, Brazil, China, Ghana, India, Iran, Italy, Norway, South Africa and the USA. The perceptions towards air quality were evaluated by employing an online survey administered in May 2020. Participants (N = 9394) in the ten countries expressed their opinions according to a Likert-scale response. A reduction in pollutant concentration was clearly perceived, albeit to a different extent, by all …
Heavy metals in coastal water systems. A case study from the northwestern Gulf of Thailand.
2005
A geochemical survey of the northwestern part of the Thailand Gulf (Inner Gulf) was carried out in order to define concentrations and distribution patterns of selected heavy metals (V, Cr, Co, Ni, Cu, Zn, and U) in the coastal system and estuarine area of the Mae Klong river. The results indicate the presence of two different sources of heavy metals in the studied environment and allowed us to identify a lithogenic component that significantly influences the composition of coastal waters and suspended particulate matter (SPM). Comparison of the normalized heavy metals concentrations both in the studied samples and in those reported for the Sn–W ores present in the surrounding areas suggests…
Pharmaceuticals in settleable particulate material in urban and non-urban waters
2011
Abstract Wastewater treatment plants (WWTP) are important sources of settleable particulate material (SPM), heading to sediments with natural suspended solids. To date, there is little information about the fate of pharmaceuticals in sediment systems. In this study, the objective was to determine if pharmaceuticals are detected in SPM at locations near WWTPs or even in rural areas, thus being susceptible for sedimentation. SPM samples were collected from 10 sites in Finland, grouped as reference, rural and wastewater effluent sites. SPM collectors were placed about 35 cm above bottom for about 2 months during summer. After extraction, a set of 17 pharmaceuticals was analyzed. Several pharma…
The effect of particulate air pollution on life expectancy.
1998
Two recent US cohort studies suggest that current levels of particulate pollution in urban air are associated not only with short-term, but also with long-term increases in cardiorespiratory morbidity and mortality. The aim of the present analyses was to evaluate the change in life expectancy assuming the long-term increase in mortality rates as suggested by these studies. The method of competing causes of death was used and the effect of particulate air pollution on life expectancy was found to be notable in countries with high cardiovascular mortality like the US.