The Krakow Receptor Modelling Inter-Comparison Exercise

Second to oil, coal is globally the biggest energy source. Coal combustion is utilized mainly for power generation in industry, but in many metropolitan areas in East Europe and Asia also for residential heating in small stoves and boilers. The present investigation, carried out as a case study in a typical major city situated in a European coal combustion region (Krakow, Poland), aims at quantifying the impact on the urban air quality of residential heating by coal combustion in comparison with other potential pollution sources such as power plants, industry and traffic. For that purpose, gaseous emissions (NOx, SO2) were measured for 20 major sources, including small stoves and boilers, and the emissions of particulate matter (PM) was chemically analyzed for 52 individual compounds together with outdoor and indoor PM10 collected during typical winter pollution episodes. The data was analyzed using multivariate receptor modeling yielding source apportionments for PM10, B(a)P and other regulated air pollutants associated with PM10, namely Cd, Ni, As, and Pb. The source apportionment was accomplished using the chemical mass balance modeling (CMB) and constrained positive matrix factorization (CMF) and compared to five other multivariate receptor models (PMF, PCA-MLRA, UNMIX, SOM, CA). The results are potentially very useful for planning abatement strategies in all areas of the world, where coal combustion in small appliances is significant. During the pollution episodes under investigation the PM10 and B(a)P concentrations were up to 8-200times higher than the European limit values. The major culprit for these extreme pollution levels was shown to be residential heating by coal combustion in small stoves and boilers (>50% for PM10 and >90% B(a)P), whereas road transport (<10% for PM10 and <3% for B(a)P), and industry (4-15% for PM10 and <6% for B(a)P) played a lesser role. The indoor PM10 and B(a)P concentrations were not much lower than the outdoor concentrations and were found to have the same sources as outdoor PM10 and B(a)P The inorganic secondary aerosol component of PM10 amounted to around 30%, which may be attributed for a large part to the industrial emission of the precursors SO2 and NOX.JRC.H.4-Transport and air qualit

Physically Constrained Receptor Modelling of PM10 from Winter Time Krakow

Krakow is Poland¿s second largest city and one of the most polluted cities in Europe with regards to particulate matter (PM) and associated compounds, such as benzo(a)pyrene (B(a)P). The study was designed to apportion coal combustion sources in comparison with other main sources for these pollutants PM10 samples were collected in Krakow during typical winter pollution events from 5 sampling sites, all with little different source profiles, industry, traffic, residential, urban background and rural background areas. The receptor samples were chemically analyzed together with PM emissions samples from 20 major sources and the obtained data was subjected to multivariate receptor modeling. 46 individual compounds were included comprising elementary and organic carbon (EC/OC), major anions and cations, trace elements, polyaromatic hydrocarbons and azaarenes. The source apportionment was accomplished by physically constrained positive matrix factorization (CMF). The hybrid receptor model between chemical mass balance and factor analysis with physically meaningful constraints was developed in the early 90ties by Wåhlin (Wåhlin, 1993). Subject for constraints was to gain reduced rotational ambiguity and physically more interpretable factors. In this study, these ideas are developed further by not only constraining ratios of specific elements, but allowing the constraint to be variable within uncertainty limits. The limits for constraints can be obtained from experimental uncertainties of source profiles or expert knowledge about specific elemental ratios, e.g. evaporation or chemical transformation that changes the original source fingerprint from one form to an other. Furthermore, the uncertainties for semivolatile PACs were scaled using temperature corrected subcooled liquid vapor pressures (Fernández et al., 2002). CMF takes advantage of the multi-linear engine ME-2 model tool developed by Paatero,(1999), which facilitate the running of PMF in various constrained modes. The highest primary contributions to the PM10 pollution in the city of Krakow and in particularbackground site Zakopane was from Home heating. In Krakow this source covers 30-50% andin Zakopane to 80-90% of total PM10, which is in agreement with high number of small stoves in Krakow and Zakopane. The second highest primary contribution of PM10 was estimated to come from industrial power generation (coal), 30-40% in Krakow and 5-10% in Zakopane to 80-90%. Traffic and re-suspension was estimated by to be lowest primary source explains to 8-10% in Krakow and less than 2% in Zakopane. The contribution from secondary aerosols was estimated to contribute with 20-21% in Krakow and less than 8-10% in Zakopane.JRC.H.4-Transport and air qualit