Regional and temporal (1992–2004) evolution of air-borne sulphur isotope composition in Saxony, southeastern Germany, central Europe†

Abstract

The isotopic composition of air-borne sulphur was investigated in Saxony, Southeast Germany--a region with formerly very high atmospheric SO(2) concentrations. In addition, data from various authors were compiled for different Saxonian locations, spanning from 1992 to 2004, i.e., a time of decreasing SO(2) concentrations in the atmosphere. There were no obvious temporal changes in the mean delta(34)S value of bulk precipitation. However, the variability of monthly mean delta(34)S values decreased. The mean sulphur isotope composition of sulphate from bulk precipitation after the year 2000 converges in Saxony towards 4-5 per thousand, with similar values for different locations. Mean values of different forms of sulphur show the following enrichment order: delta(34)S of SO(2) < delta(34)S of weathering crusts < or =delta(34)S of sulphate from bulk precipitation < or =delta(34)S of dust. Judging from local differences on sulphate crusts and corresponding isotope values of sources, the delta(34)S value of SO(2) as well as for crusts mainly reflects local point sources. The mean delta(34)S value of bulk precipitation represents more regionally well-mixed SO(2) sources and is therefore an ideal tool for monitoring regional atmospheric change.

Sulfur isotope fractionation during oxidation of sulfur dioxide: gas-phase oxidation by OH radicals and aqueous oxidation by H&lt;sub&gt;2&lt;/sub&gt;O&lt;sub&gt;2&lt;/sub&gt;, O&lt;sub&gt;3&lt;/sub&gt; and iron catalysis

“…However, for field studies measuring the isotopic composition of both ambient SO 2 and sulfate, the major limitation to interpreting atmospheric isotope measurements is the lack of laboratory studies of the isotopic fractionation factors involved in the most common atmospheric reactions of sulfur (Tanaka et al, 1994;Novak et al, 2001;Tichomirowa et al, 2007). For heterogeneous oxidation, equilibrium fractionation of 34 S/ 32 S during the uptake of SO 2 into solution and the subsequent acid-base equilibria has been measured in several studies.…”

Regional and temporal variability of the isotope composition (O, S) of atmospheric sulphate in the region of Freiberg, Germany, and consequences for dissolved sulphate in groundwater and river water

“…Mean annual sulphate concentrations in atmospheric deposition of the Freiberg region from 2009-2010 (Table 1: 1.7-3.5 mg l −1 ) did not change significantly since 1997 [21,23]. Sulphate concentrations from additional sampling locations pr3, pr4, pr5 also remained constant.…”

“…The low concentrations of zinc reflected the low impact of the oxidation of residual sulphide ores [21,23,25]. The sulphate concentration did not vary markedly ( Table 2) and was the same as in 2006 [22].…”

“…Bulk precipitation sampled over periods of 1 month or longer is a good representative for long-term changes in the atmospheric sulphur cycle [21]. Up to the year 1990, the highest atmospheric sulphur deposition loads in Central about 30 km north of Freiberg, (ii) Oberbärenburg close to the border to the Czech Republic and to the summit of the Erzgebirge mountains (735 m a.s.l.…”

δ 34 S values and S concentrations in native and transplanted Pleurozium schreberi in a heavily industrialised area

“…The sulphur isotope was established as À 1 to þ8‰ (most data are from þ 3.5 to þ7‰) in coal and from þ2 toþ15‰ in lignite of Polish origin (Chmielewski et al, 2002;Derda et al, 2006). Additionally δ 34 S in rainfall deposition being a source of sulphur for mosses was from 2.5‰ to 3.0‰ (southwest Poland), 6‰ (south-central Poland), from 4 to 5‰ (southeast Germany) and from 7 to 8‰ (north Czech Republic) (Jędrysek, 2000;Tichomirowa et al, 2007;Górka et al, 2008;Migaszewski et al, 2010;Górka et al, 2011). The δ 34 S values reported for gasoline and diesel in Canada varied from þ5 to þ9‰ for fuel sulphur and exhaust products of its combustion (Norman et al, 2004).…”