Speciation of Polysulfides and Zerovalent Sulfur in Sulfide-rich Water Wells in Southern and Central Israel

Abstract

Zerovalent sulfur and inorganic polysulfides were determined in nine sulfiderich water wells in central and southern Israel. Although the two locations belong to the same aquifer, they are characterized by different pH and hydrogen sulfide levels. Hydrogen sulfide in the central Israel wells ranged between 19 and 32 lM, and the pH was 7.26 ± 0.07. The southern basin is characterized by lower water circulation, lower pH (around 6.8), and higher hydrogen sulfide levels ([470 lM). Polysulfides were determined by a rapid single-phase methylation using methyl trifluoromethanesulfonate (methyl triflate) reagent. The summary polysulfide concentration for S 4 2--S 7 2-species was found to be around 0.14-0.75 lM in the central region of Israel and substantially higher, 2.3-4.6 lM in the southern region. The sum of polysulfide zerovalent sulfur and colloidal sulfur was quantitatively detected by cyanide derivatization and compared to polysulfide sulfur determined by methyl triflate derivatization and to the chloroform extraction of zerovalent sulfur. A method for the determination of sulfur undersaturation level-the ratio between dissolved elemental sulfur and its equilibrium concentration in the presence of solid sulfur-based on the observed levels of the major polysulfide species is described. The observed polysulfide speciation was compared with the predicted speciation under sulfur saturation conditions taking into account the water temperature, its ionic strength, and pH. Criteria for sulfur saturation versus unsaturated conditions were established based on (1) the chain length dependence of the ratio between the observed polysulfide concentrations and their predicted value under sulfur saturated conditions, and (2) the difference between the concentration of zerovalent sulfur, as determined by cyanolysis, and the total polysulfide sulfur. According to this dual criterion five of the water wells were classified as being undersaturated with respect to sulfur, though for all the examined water wells the majority of the zerovalent sulfur was in the form of polysulfide sulfur.

Sulfur Cycling in an Iron Oxide-Dominated, Dynamic Marine Depositional System: The Argentine Continental Margin

“…The ferrous iron can result from iron (oxyhydr) oxide reduction coupled to in situ sulfide oxidation, but it can also diffuse to the sulfidic zone-originating from the upper sediment layers and associated organoclastic iron reduction and the lowermost sediments via iron-reduction coupled to AOM as discussed by Riedinger et al (2014) for Site GeoB 13863. In absence of free sulfide, or at low pH (Kamyshny et al, 2004(Kamyshny et al, , 2007(Kamyshny et al, , 2008Kamyshny and Ferdelman, 2010), elemental sulfur is the stable zero-valent sulfur phase. At the investigated sites, the pH is high (7.66-8.14 in the sulfidic zone at Site GeoB 13863).…”

Hydrogen Sulfide in Biochemistry and Medicine

“…5) (88,89,225). From a structural viewpoint, a sulfane sulfur atom in an electrically neutral molecule is always attached to another sulfur atom and is either in an oxidation state of zero, or in an oxidation state of -1, and is attached to a hydrogen atom or to an ''activating group'' such as allyl, benzyl, phenacyl, etc.…”

“…Hydrogen peroxide is the physiological oxidant of choice because it is constitutively produced inside most cells at various loci such as mitochondria, peroxisomes, and the cytosol mainly via enzymatic processes mediated by SOD, NADPH oxidases, xanthine oxidases, sulfhydryl oxidases, thiol oxidases, and monoamine oxidases (27,83), and the reactivity of hydrogen peroxide toward thiols and H 2 S is high (140). Hydrogen peroxide generation in mammals is probably in the vicinity of 50 lmol kg (224) as sulfur that reacts, at pH 8.5-10, with cyanide to yield thiocyanate (88,89,225). From a structural viewpoint, a sulfane sulfur atom in an electrically neutral molecule is always attached to another sulfur atom and is either in an oxidation state of zero or in an oxidation state of -1 and is attached to a hydrogen atom or to an ''activating group'' such as allyl, benzyl, phenacyl, etc.…”

Reduced sulfur species in a stratified seawater lake (Rogoznica Lake, Croatia); seasonal variations and argument for organic carriers of reactive sulfur

“…Together with dissolved molecular S 0 , polysulfides are believed to be the most important carriers of zero-valent sulfur in natural waters. Until recently, efforts to quantify them in natural waters have been few in number and in many cases incomplete, although the situation has been continually improving (Boulègue et al, 1982;Luther et al, 1986;Gagnon et al, 1996;Overmann et al, 1996;Miller et al, 1998;Wang et al, 1998;Gun et al, 2000;Kamyshny et al, 2008;Wang and Tessier, 2009).…”