This study examines platinum group element concentrations (PGE) (i.e. platinum (Pt), palladium (Pd) and rhodium (Rh)) and their spatial distribution in airborne particulate matter fractions (PM) of ...human health concern in urban and rural areas of Germany. Fractionated airborne dust and PM10, PM2.5 and PM1 samples were collected along a busy road in Frankfurt am Main from July 2008 to April 2010. PM10 was also sampled in Deuselbach and Neuglobsow between January 2008 and July 2009 to examine their concentrations at rural locations and potential for long-range transport.
Pt, Pd and Rh were isolated and pre-enriched in samples using a combination of Te and Hg co-precipitation methods. Concentrations were determined using isotope dilution ICP-Q-MS (in collision mode with He).
The highest airborne PGE concentrations were measured in PM10 from Frankfurt (e.g. 12.4pg Pt/m3 (mean)), while the rural locations of Deuselbach and Neuglobsow exhibited the lowest levels (e.g. 2pg Pt/m3 (mean)). PGE concentrations were observed to decline with increasingly smaller PM size fractions from PM10 to PM1. All size fractions generally contained higher levels of Pd compared to Pt and Rh, an element of greater concern due to its solubility. PM2.5 collected in Frankfurt had a mean of 16.1pg Pd/m3, compared to 9.4pg/m3 for Pt. PGE concentrations also demonstrated a distinct seasonal relationship, with the greatest levels occurring in winter. Compared to a previous study in 2002, PGE concentrations in fractionated airborne dust have significantly increased over time. Elevated PGE levels were also measured for PM10 sampled in Neuglobsow and Deuselbach, which could not be attributed to local emission sources. Using the diagnostic meteorological model, CALMET, trajectory analyses confirmed our hypothesis that PGE are being transported over longer distances from other areas of Europe.
► Platinum group element (PGE) levels in airborne PM of human health concern have increased with time. ► Data on platinum (Pt), rhodium (Rh) and palladium (Pd) levels in PM1 reported for first time. ► PGE concentrations in rural areas of Germany do not reflect local emission sources. ► PGE are likely transported long-distances from urban to rural locations. ► PGE concentrations in airborne PM are higher in winter compared to summer.
Mercury (Hg) is still a focus of environmental research, since its levels in fish frequently exceed the Environmental Quality Standard (EQS) of 20 µg/kg for biota defined by the European Water ...Framework Directive (Directive 2008/105/EC). Current Hg levels in Abramis brama from German rivers are in the range of 73–346 µg/kg wet weight (2009) and exceed the EQS by a factor of 3.7–17.3. Therefore, it is important to identify the sources of Hg pollution in the aquatic environment and to develop effective strategies for reducing the input into associated river systems. The aim of the present study was to analyze Hg in the urban water cycle of the city of Frankfurt am Main, Germany. Samples were taken from the river Main crosscutting the city and its tributaries. In addition, precipitation, stormwater runoff, effluents of two municipal WWTPs, and stormwater management structures such as combined sewer overflows and stormwater retention basins have been analyzed. Loads of Hg have been determined based on the measured concentrations and a Hg mass balance for the aquatic system was created. A total of 160 water samples were analyzed by cold vapor atomic fluorescence spectroscopy (CVAFS) according to US EPA Method 1631. Results from the mass balance have shown that approximately 5 kg Hg/a enter and 15 kg Hg/a leave the study area of Frankfurt am Main via the river Main. The largest amount of Hg (24.58 kg/a) throughout the urban water cycle of Frankfurt am Main is transported via wastewater. However, municipal WWTPs in Frankfurt am Main have been identified as the largest Hg sink, since 99.7% (24.5 kg/a) of the Hg is shifted from the sewage water and stormwater during treatment into the sewage sludge. Thus, the increase of the Hg load in the river Main from 5 to 15 kg/a has to be attributed to other sources such as 3 industrial WWTPs, groundwater and non-treated stormwater runoff during heavy rain events.
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