Speciation of Sulfur in Peat in Four Locations in the Northwestern Netherlands

Abstract

The peat areas in the Netherlands demonstrate a high amount of sulfur of up to 8-9 wt%. In order to investigate the S speciation in Dutch peat, peat samples from four locations in the northwestern Netherlands were analyzed. The three main objectives of this study are: to determine the relative abundance of elemental S in comparison to the other inorganic S species; to examine whether the availability of reactive iron is associated with the presence of elemental sulfur in peat; and to search for, if any, differences in S speciation between peat from a marine and that from a fluvial paleoenvironment. Sequential wet chemical extraction of S was performed to fractionate the total S into different inorganic sulfur species, such as acid volatile sulfur (AVS), elemental sulfur, and chromium-reducible sulfur (CRS). In all samples, pyritic S was the dominant inorganic S species, followed by AVS, SO42-, and S0. The concentrations of S0 were consistently low in all samples, revealing no significant correlation with reactive Fe availability. The S content in marine and fluvial paleoenvironment differed with respect to the balance between total inorganic and organic S fraction, where the riverine peat demonstrated a higher total S and total inorganic S fraction than the marine peat. Future researchers of Dutch peat may benefit from these findings, as they reveal the relative abundance of different inorganic S species with the addition of elemental S to the inorganic S species.