Source apportionment of highly time resolved trace elements during a firework episode from a rural freeway site in Switzerland

Abstract

<p><strong>Abstract.</strong> Trace element measurements in PM<sub>10</sub> were performed with 1 h time resolution at a rural freeway site during summer 2015 in Switzerland using the Xact multi-metals monitor. On average the Xact 625 elements (without accounting for oxygen and other associated elements) make up about 20 % of the total PM<sub>10</sub> mass (14.6 µg m<sup>−3</sup>). Subsequently, a source apportionment by positive matrix factorization (PMF) implemented via the Source Finder software (SoFi Pro) was applied. Eight different sources were identified (notable elements in brackets) for PM<sub>10</sub>: fireworks-I (K, S, Ba, Cl), fireworks-II (K), sea salt (Cl), secondary sulfate (S), background dust (Si, Ti), road dust (Ca), traffic-related (Fe) and industrial (Zn, Pb). The major components were secondary sulfate and traffic-related followed by background dust and road dust factors, explaining 21 %, 20 %, 18 % and 16 % of the analysed PM<sub>10</sub> elemental mass, respectively, with the factor mass not corrected for oxygen content. Further, there are minor contributions (on the order of a few percent) of sea salt and industrial sources. The regionally influenced secondary sulfate factor experiences negligible resuspension, and concentrations are similar throughout the day. The significant loads of the traffic-related and road dust factors with strong diurnal variations highlight the continuing importance of vehicle-related air pollutants at this site. Enhanced control of PMF using SoFi Pro allowed for a successful apportionment of transient sources such as the two firework factors and sea salt, which remained mixed when analysed by unconstrained PMF.</p>

Extrapolation of anthropogenic disturbances on hazard elements in PM2.5 in a typical heavy industrial city in northwest China

“…The abundance of elements K, Ba, and Br increased at the lockdown period. As known, K and Ba could be emitted by household fireworks for the traditional celebration during the Chinese Spring Festival) (Rai et al 2020 ; Yao et al 2019 ). Except for K, Ba, and Br, the mass concentrations of other elements showed declines in the lockdown period.…”

Sources and processes of iron aerosols in a megacity of Eastern China

“…Se and As are tracers for the coal burning sources (Cui et al, 2019). Rai et al (2020), Cai et al (2017), and Chang et al (2018) reported that Pb and Fe are mainly derived from steel industry or smelter. Liu et al (2019) suggested that Co originate from the metal industry sources, and Cr is widely used in electroplating and leather industries.…”

Supplementary material to "Sources and processes of iron aerosols in a megacity of Eastern China"

“…Factor 5 was characterized by high loads of Cr, Co, Ni, Cu, Sr, Ba, and Pb, indicating non-combustion related industrial emission (Cai et al, 2017;Chang et al, 2018;Liu et al, 2019;Rai et al, 2020). High loads of Cr, Mn, Cu, Zn, Se, Pb in factor 6 suggested traffic emission (Alias et al, 2020;Lin et al, 2015).…”