Using stable isotopes to trace sources and formation processes of sulfate aerosols from Beijing, China

Abstract

Particulate pollution from anthropogenic and natural sources is a severe problem in China. Sulfur and oxygen isotopes of aerosol sulfate (δ34Ssulfate and δ18Osulfate) and water-soluble ions in aerosols collected from 2012 to 2014 in Beijing are being utilized to identify their sources and assess seasonal trends. The mean δ34S value of aerosol sulfate is similar to that of coal from North China, indicating that coal combustion is a significant contributor to atmospheric sulfate. The δ34Ssulfate and δ18Osulfate values are positively correlated and display an obvious seasonality (high in winter and low in summer). Although an influence of meteorological conditions to this seasonality in isotopic composition cannot be ruled out, the isotopic evidence suggests that the observed seasonality reflects temporal variations in the two main contributions to Beijing aerosol sulfate, notably biogenic sulfur emissions in the summer and the increasing coal consumption in winter. Our results clearly reveal that a reduction in the use of fossil fuels and the application of desulfurization technology will be important for effectively reducing sulfur emissions to the Beijing atmosphere.

Characteristics and Sources of Hourly Trace Elements in Airborne Fine Particles in Urban Beijing, China

“…SOR also increased with the increase of As, Se, Pb, and Hg. Considering that As, Se, Pb, Hg, and SO 2 or sulfate from SO 2 conversion mainly originated from coal combustion (Guo et al, ; Han et al, ; Tian et al, ), they may correlate well with each other. However, As, Se, Pb, Hg, and sulfate may also correlate well with each other under the same meteorology.…”

Assessing Contamination Sources by Using Sulfur and Oxygen Isotopes of Sulfate Ions in Xijiang River Basin, Southwest China

“…After 48 h, the mixture was filtered through ∼0.22‐μm membrane filters. The BaSO 4 sediment of filter will be carefully rinsed with Milli‐Q water to remove Cl − and then transferred to crucibles, under the temperature of 800°C in air combustion for 40 min (Han et al, 2016). The δ 34 S SO4 of BaSO 4 was determined on a Finnigan Delta‐C isotope ratio mass spectrometer coupled with an elemental analyzer in a continuous‐flow mode.…”

“…Investigations of river water chemistry and isotopic composition allow us to understand chemical erosion processes and viable carbon dioxide (CO 2 ) consumption reservoirs, and to provide clues about the long-term climatic evolution (Negrel et al, 1993;Gaillardet et al, 1999;Millot et al, 2003;Xu and Liu, 2007;Han et al, 2010;Li and Ji, 2016). Previous studies suggested that silicate weathering regulates the greenhouse effect on a geological timescale (Walker et al, 1981;Gaillardet et al, 1999;Galy and France-Lanord, 1999;Han et al, 2016;Li and Ji, 2016). Moreover, the acidic solution produced during oxidation of sulfide to soluble sulfate (SO 4 2− ) also plays an important role in weathering carbonate (Calmels et al, 2007;Li et al, 2008Li et al, , 2013.…”

First Assessment of NOx Sources at a Regional Background Site in North China Using Isotopic Analysis Linked with Modeling

“…38 The use of K + as a tracer of biomass burning has been established, 39 while SO 4 2− results from the transformation of SO 2 , which is mostly produced from industrial or domestic coal combustion in China. 40 There was a relatively strong correlation between SO 4 2− and NO 3 − in winter and spring when large amounts of coal were consumed for heating, further implying that NO 3 − in the two seasons originated from coal combustion. In addition to the combustion signals, "fuel NH 4 + " (Text S7) displayed a significant relationship with NO 3 − , also indicating that it had a combustion source (e.g., vehicle exhaust and power plants).…”