Sulfides water

Iron levels of 1 to 10 ppm Fe often are found in subsurface waters. This may rise to perhaps 25 ppm Fe in seriously anaerobic water sulfides usually are also present. 

Mau AWH, Huang CB, Kakuta N, Bard AJ, Campion A, Eox MA, White JM, Webber SE (1984) Hydrogen photoproduction by Nafion/cadmium sulfide/platinum films in water/sulfide ion solutions. J Am Chem Soc 106 6537-6542... 

Zheng Y, Anderson RF, van Geen A, Kuwabara J (2000a) Authigenic molybdenum formation in marine sediments A link to pore water sulfide in the Santa Barbara Basin. Geochim Cosmochim Acta 64 4165-4178... 

The other metals exhibit different vertical profiles. The dissolved concentrations of Pb and Cu do not exhibit subsurface concentration maxima and, hence, do not appear to undergo any redox reactions. Their dissolved concentrations decline with increasing depth and are likely controlled by precipitation into sulfide minerals as the particulate concentrations increase rapidly with depth in the anoxic zone. In the anoxic waters, sulfide is supplied by in situ sulfate reduction. 

ITiJ TKOPr-iU. h Molar ratio water/sulfide. 

The corrosion behavior tends to follow much the same pattern in clean sea water the world over. If there is pollution, it may cause an unbalance of the pH, change the marine organism concentration, decrease the dissolved oxygen, or alter the ionic balance of sea water. Pollution normally results in saline waters becoming considerably more aggressive to one or more metals. Specific tests must be made to determine the applicability of a metal in each type of polluted water. Sulfides, which are often found m such waters, tend to promote corrosion of both ferrous and nonferrous metals. 

Unsymmetrical sulfides 39 need the same disconnection we have just used for ethers. The anion 41 of a thiol 42 will combine with an alkyl halide 40 to make a new C-S bond. The reaction is much easier with sulfur. Thiols are more acidic than alcohols, just as H2S is more acidic than water. Sulfide anions 41 are more nucleophilic towards saturated carbon than are alkoxides and the risk of elimination is much less. 

McKee, K.L., Mendelssohn, I.A., and Hester, M.W. (1988) Reexamination of pore water sulfide concentrations and redox potentials near the aerial roots of Rhizophora mangle and Avicenna germinans. Am. J. Bot. 75 1352-1359. 

Nearly all alkali metal compounds are soluble in water. Sulfide and phosphate compounds are usually insoluble. How, then, do you account for the fact that sodium sulfide and potassium phosphate are soluble, while iron sulfide and calcium phosphate are insoluble Why do some ions form soluble compounds, while other ions form insoluble compounds ... 

Effect of pH on the solubility of acidic and basic substances. Solubility of calcium carbonate in water. Sulfide precipitation. Values of solubility products. 

S content of total solid-phase sulfur. Spy pyrite sulfur content. 6Spy isotopic composition of pyiite. Sorg organic sulfur. S elemental sulfur. SO4 pore-water sulfate concentration. 5SO4 isotopic composition of pore-water sulfate. H2S pore-water sulfide concentration. 5SH2S isotopic composition of pore-water sulfide. SRR sulfate reduction rate. 

The source of the oxidant in the severely impacted wells is most likely the borehole. The strong correlation between high arsenic and the interface of the SCH with the static water level in the well, in both confined and unconfined areas if the St. Peter aquifer, indicates that this interaction exerts significant control on arsenic release. Under confined conditions, the air-water-sulfide interface only occurs within the well. Field data also show that in the confined portion of the aquifer, the DO concentration in borehole water is significantly higher than in formation water. The borehole appears to promote oxidation of sulfides in the SCH in wells where the static water level is approximately coincident with the SCH. 

Nickerson, N.H. and Thibodeau, F.R. (1985) Association between pore water sulfide concentrations and the distribution of mangroves. Biogeochemistry, 1, 183—192. 

In conclusion, several alternative mechanisms for the thiolsulfinate hydroperoxide reaction have been suggested. The results indicate that nucleophilic displacement on tert-butyl ferf-butanethiolsulfinate by water, sulfides, and disulfide does not play a significant role under the conditions cited. The possibility of a homolytic process has been considered, and evidence indicates that radicals play an essential role in formation of the active peroxide decomposing species, that then function primarily via a... 

The sulfide melts have unique chemical properties. Chemical reactions which occur in water do not always occur in sulfide melts. The author was surprised to find evidence of strong oxidizing ions, such as peroxides, dissolved in sulfide melts. In water, sulfide ion will reduce iodine to iodide and potassium peroxide, and superoxide will oxidize aqueous iodide solutions to iodine, or further to periodate ion. It is not surprising that much of the literature about pyrotechnically produced sulfide melt sparks is filled with reports of chemical species which do not exist at 800°C, such as the thiosulfate ion. These ions are quickly formed when the melts are dissolved in water prior to analysis. The author found radically different chemistry occurring at room temperature for spark droplets only seconds after collection by freezing. Some of the sulfide melts studied were not stable for more than one half second after capture. Special handling techniques were, and are, being developed. As techniques evolve the future may yield better data. Chemistry is an effort to be better informed tomorrow than is possible today. 

Some specific corrosion environments, in the presence of applied tensile stress on the metal siuface (above some threshold vtilue), can cause stress-corrosion cracking (SCC). The somce of stresses can be extemtil, but residual stresses can tilso cause SCC failures. Specific corrosive pollutants, which may contribute to the SCC of carbon steels, are for example, the carbonates in water. Sulfide stress cracking (SSC) commonly occms on the outside of a pipe where sulfate-reducing bacteria me present at a soil pH of 3-7. Because of the produced iron sulfide (FeS), which adsorbs readily on the steel surface, hydrogen atoms generated... 

Black water Sulfide corrosion of copper and iron... 

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