Effect Of Thiosulfate Research Articles

Microscopic behavior of single corrosion pits: the effect of thiosulfate on corrosion of stainless steel in NaCl

Pitting corrosion of Type 304 and 316 stainless steels was investigated in neutral chloride solutions containing various concentrations of thiosulfate (0.01 to 500 mM) and chloride (1 to 1000 mM). The effect of thiosulfate on pitting corrosion of stainless steel 304 was quantitatively studied at the microscopic level by initiating single pits on small wires in neutral chloride solutions containing thiosulfate. Analysis of single pit data indicated that thiosulfate may promote stability through either a cathodic side-reaction or through the existence of a salt film. In galvanostatic experiments, the potential response exhibited six types of behavior that depended on the concentrations of chloride and thiosulfate. Thiosulfate was found to promote the sustained growth, or stability, of pits within a concentration range that depended upon the concentration of chloride ion. An excess of thiosulfate prevented pit formation. Type 316 stainless steel required higher concentrations of thiosulfate to produce stable pits, as compared to Type 304. The effect of surface adsorption of thiosulfate on pitting of 316 stainless steel was investigated by an in situ radiotracer method. It was found that the extent of thiosulfate surface adsorption differed for the three levels of chloride in 0.1 mM Na 2S 2O 3, and that an increase in the surface concentration of thiosulfate from the small pit region caused formation of large pits.

Effects of thiosulfate and tetrathionate on urease activity and seedling growth

Abstract Interest in use of ammonium thiosulfate (ATS) in conjunction with urea as a fertilizer has been stimulated by reports that ATS retards hydrolysis of urea by soil urease. We recently found, however, that ATS significantly retarded urea hydrolysis in soil only when applied at very high rates (>2,500 (μg/g soil) that adversely affected seedling development. Because ATS is rapidly oxidized in soil, we compared the effects of thiosulfate and its oxidation products (tetrathionate, sulfite, and sulfate) on urea hydrolysis and seedling development in soil and hydrolysis of urea by jackbean urease. We found that the inhibitory effect of thiosulfate on urea hydrolysis in soil is due to tetrathionate formed by oxidation of thiosulfate and that both thiosulfate and tetrathionate have an adverse effect on seedling growth of wheat and corn in soil. Tetrathionate at concentrations of 2,500 and 5,000 μ.g/mL inhibited hydrolysis of urea by jackbean urease, whereas thiosulfate had no inhibitory effect at these con...

Effect of thiosulfate and of sulfide on biochemical oxidation of surface-active substances

The degree of inhibition of the wastewater clean-up process from surface-active substances is increased with increase in thiosulfate ion concentration. On increase in thiosulfate ion concentration to 400 mg/liter, the SAS in the aeration tanks are essentially not oxidized. At a thiosulfate ion concentration in wastewater of 50–100 mg/liter, the efficiency of clean-up from SAS by the two-stage scheme is higher than that by the one-stage scheme at an identical overall duration of aeration. Sulfide ion begins to exert a marked inhibiting effect on the biochemical process of purifying wastewater from SAS at concentrations above 40 mg/liter.

The effect of thiosulfate on phosphorus availability and uptake by plants

Abstract A growth chamber experiment was conducted to examine the effect that banding urea or a thiosulfate source with monoammonium phosphate had upon fertilizer phosphorus uptake and dry matter yield of barley and rapeseed. For barley, fertilizer phosphorus uptake and dry matter yield were significantly increased when a thiosulfate source was banded with monoammonium phosphate, but not when urea was banded with monoammonium phosphate. Fertilizer phosphorus uptake and dry matter yield of rapeseed were not significantly affected by banding either a thiosulfate source or urea with monoammonium phosphate.

Thiosulfate as an Oxidation Inhibitor in Flue Gas Desulfurization Processes: A Review of R&D Results

Sodium thiosulfate (Na2S2O3) has been tested in a pilot plant as an oxidation inhibitor in flue gas desulfurization by lime and limestone slurry scrubbing with and without MgO and adiplc acid additives. The effectiveness of thiosulfate is proportional to the inhibitor product, defined as the product of thiosulfate concentration (M), calcium concentration (M), and the moles of SO2 absorbed per hour per liter of hold tank volume. Gypsum saturation was less than 100 percent and scaling was eliminated when the inhibitor product exceeded 0.3 × 10−6(gmol/L)3/h. Thiosulfate was relatively more effective in systems with chlorides and less effective in systems promoted by MgO. An inhibitor product greater than 10−6(gmol/L)3/h significantly enhanced dewatering of solids from limestone scrubbing. SO2 removal and/or limestone utilization were increased in systems that started with less than 10 mM dissolved calcium.

Effect of Thiosulfate on Crevice Corrosion of Stainless Steels

Abstract Crevice corrosion studies were conducted on AISI 304, AISI 316L, and UHB 904L stainless steels using Teflon/metal crevices exposed to aqueous solutions of 1M NaCl and 1M NaCl + 0.01 M Na2S...

Effects of thiosulfate on cyanide pharmacokinetics in dogs

One method to treat cyanide poisoning involves the administration of a combination of sodium thiosulfate and sodium nitrite. Sodium thiosulfate is believed to exert its antidotal effect by serving as a sulfur donor, thereby increasing the rate of rhodanese catalyzed biotransformation of cyanide to thiocyanate. To gain insight into the mechanism of action of thiosulfate on cyanide toxicity, a pharmacokinetic analysis of cyanide distribution and metabolism with and without sodium thiosulfate was conducted in mongrel dogs. A compartmental model for thiocyanate, the major metabolite of cyanide, was developed from plasma concentrations determined at various times after iv administration of thiocyanate; sodium thiosulfate did not alter thiocyanate-model parameters. The model for thiocyanate was coupled to a model for cyanide, and model based equations were fitted to the blood levels of both cyanide and thiocyanate that were measured after iv administration of cyanide. This kinetic analysis showed that thiosulfate increased the rate of conversion of cyanide to thiocyanate over 30-fold. The mechanism of thiosulfate protection appeared to be due to extremely rapid formation of thiocyanate in the central compartment, which thereby limited the amount of cyanide distribution to sites of toxicity.

Biochemical characterization of neonatal multiple sulfatase deficient (MSD) disorder cultured skin fibroblasts

Cultured skin fibroblasts of a patient with a neonatal onset of MSD can be distinguished from usual type of MSD cells by enzyme assays of arylsulfatases A, B and C activities, effect of thiosulfate on arylsulfatase A activity and 35SO 4-acid mucopolysaccharide accumulation and degradation. These data suggest that neonatal onset of MSD is a distinct disorder from usual type of MSD in term of genetic occurence.

Thiosulfate stimulation of microbial dark assimilation of carbon dioxide in shallow marine waters

The effect of thiosulfate on dark assimilation of carbon dioxide in shallow marine environments was investigated in order to explain the recent discovery of bacterial thiosulfate oxidation in aerobic, open ocean seawater. The results demonstrate that the potential exists for microbial thiosulfate oxidation to increase both dark assimilation of carbon dioxide and the utilization of organic compounds in the sea. Thiosulfate-stimulated microbial activity may be caused not only by chemoautotrophic sulfur bacteria, but also by heterotrophic species which oxidize thiosulfate to tetrathionate. Measurements of dark assimilation of carbon dioxide made at different incubation times indicate that great care must be taken both in experimental procedure and in interpretation of results obtained with the dark assimilation technique.