Sulfur isotopic fractionation between sulfur and sulfuric acid in the hydrothermal solution of sulfur dioxide

Abstract

Sulfur and sulfur compounds involved in the chemical reaction, 3H2SO3= 2H2SO4+S+H2O in the temperature range from 150 to 300°C have been quantitatively determined. After the disproportionation reaction of sulfurous acid is completed, sulfur decreases according to the chemical reaction, 4S+4H2O = 3H2S+H2SO4. These two reactions may be responsible for the production of sulfuric acid in hot spring water. 34S is enriched in sulfuric acid and depleted in sulfur revealing 16.1 to 21.1‰ fractionation between them. This would account for the enrichment of 34S in sulfuric acid encountered in hot spring water.