Showing papers on "Sodium sulfide published in 2006"

Development of cost-effective noncarbon sorbents for Hg(0) removal from coal-fired power plants.

Abstract: Noncarbonaceous materials or mineral oxides (silica gel, alumina, molecular sieves, zeolites, and montmorillonite) were modified with various functional groups such as amine, amide, thiol, urea, and active additives such as elemental sulfur, sodium sulfide, and sodium polysulfide to examine their potential as sorbents for the removal of elemental mercury (Hg(0)) vapor at coal-fired utility power plants. A number of sorbent candidates such as amine- silica gel, urea- silica gel, thiol- silica gel, amide-silica gel, sulfur-alumina, sulfur-molecular sieve, sulfur-montmorillonite, sodium sulfide-montmorillonite, and sodium polysulfide-montmorillonite, were synthesized and tested in a lab-scale fixed-bed system under an argon flow for screening purposes at 70 degrees C and/or 140 degrees C. Several functionalized silica materials reported in previous studies to effectively control heavy metals in the aqueous phase showed insignificant adsorption capacities for Hg(0) control in the gas phase, suggesting that mercury removal mechanisms in both phases are different. Among elemental sulfur-, sodium sulfide-, and sodium polysulfide-impregnated inorganic samples, sodium polysulfide-impregnated montmorillonite K 10 showed a moderate adsorption capacity at 70 degrees C, which can be used for sorbent injection prior to the wet FGD system.

Adsorption studies of smithsonite flotation using dodecylamine and oleic acid

Abstract: The interaction of various concentrations of sodium sulfide, dodecylamine (DDA) and oleic acid (OA) on smithsonite were investigated at different pH levels using zeta potential, contact angle, microflotation and diffuse-reflectance FT-IR studies. Flotation results show that the recovery and contact angle are enhanced to 94% and 115°, respectively, with a dodecylamine concentration of 1.6 × 10t−3 M and a pH of 11.5. The optimum sodium sulfide consumption was found to be 2.6 × 10−2 M. Zeta potential measurements showed less negative charge after DDA treatment on the surface of pure crystalline smithsonite. The recovery and contact angle for oleic acid flotation rises to 93% and 105°, respectively, with an oleic acid concentration of 1.1 × 10−3 M and a pH of 10. The zeta potential in the case of using oleic acid showed a more negative charge after oleic acid treatment on the smithsonite surface. The FT-IR spectra studies of smithsonite conditioned with DDA confirmed the adsorption of DDA on the smithsonite surface. The spectra show that the mineral surface is changed partially to a ZnS layer after sodium sulfide treatment. The spectra confirmed the formation of zinc oleate on the smithsonite surface after oleic acid treatment. A comparison of the results using cationic and anionic collectors showed that the different adsorption densities of the reagents in two cases conferred different degrees of hydrophobicity on the smithsonite surface.

A novel electrochemical preparation of PbS nanoparticles

Abstract: A simple one-step anodic sonoelectrochemical method to synthesize PbS nanoparticles has been developed. With the lead foil as the sacrificing anode, Pb(II) was anodically dissolved from the lead electrode into the aqueous solution of sodium sulfide, supporting electrolyte (potassium nitrate) and capping agent (PVA) at a constant potential, and then the produced Pb(II) reacted with the sulfide anion to form PbS nanoparticles under ultrasonic irradiation. The effects of the applied potential, capping agent and ultrasound in the formation of PbS nanoparticles are discussed, and the results suggest that the anodic sonoelectrochemical method may be a general and convenient way to prepare metal sulfide nanoparticles.

Short Communication Removal of insoluble heavy metal sulfides from water

Abstract: The necessity of heavy metal removal from wastewater has led to increasing interest in absorbents. We have developed a new approach to obtain high metal adsorption capacity by precipitating metal sulfides with sodium sulfide on the surface of bentonite and adhere them to the absorbent. This method allowed to remove approximately 90% of cadmium as CdS from 10 � 4 –10 � 6 M CdCl2 solutions. Additional reactions are related to the removal of excess sodium sulfide by the release of hydrogen sulfide and oxidation to sulfur using carbogen gas (5% CO2, 95% O2) followed by aeration.

Chromium Redox Chemistry in Drinking Water Systems

Abstract: In order to understand the redox chemistry of chromium at low concentrations (100 μg∕L) under conditions typically found in drinking water systems, three reductants and four oxidants were tested in three different waters at pH 5, 7, and 9. In the absence of any oxidant or reductant, Cr(VI) was stable at all three pHs, while Cr(III) precipitated out of solution at pH 9 and greatly impacted the reduction reactions. Stannous chloride was more effective than sodium sulfite or sodium sulfide for reducing Cr(VI) to Cr(III). Sulfide is not likely to be used as a reductant due to the long reaction time (120 h) to achieve the same reduction as Sn Cl2 , while sulfite may be effective at higher doses. The oxidation of Cr(III) by dissolved oxygen and chloramine was very slow, while Cl2 and KMn O4 were effective oxidants under many conditions. A Cl2 residual in a drinking water distribution system may oxidize any soluble Cr(III) to Cr(VI) because of the long contact time, so Cr treatment strategies will need to remove...

A Fast and Large-Scale Synthesis of 3-Formyl-2-mercaptoquinolines

Abstract: A convenient, efficient, and inexpensive procedure for the synthesis of 3-formyl-2-mercaptoquinolines 2a–l has been developed by a simple one-pot reaction of 3-formyl-2-chloroquinolines 1a–l with sodium sulfide and hydrochloric acid in ethanol. The structures of all the synthesized compounds were elucidated on the basis of elemental analyses and IR, 1 H NMR, and mass spectral data.

Spectral Monitoring of the Formation and Degradation of Polysulfide Ions in Alkaline Conditions

Abstract: The recently developed protocol for the absolute determination of the various polysulfide species based by 1H NMR was applied to monitor the amount of such ions in alkaline media produced at different conditions. The thermal stability of each individual polysulfide species was also evaluated in temperature ranges representative of a typical alkaline pulping process. Overall, the species, S12-, S22-, S32-, S42-, S52-, and S62- were detected and quantified in all alkaline conditions evaluated. The concentration of sodium sulfide and the temperature were found to have a significant effect on the total amount of polysulfides detected. In summary, the di- and trisulfide anions were found to predominate over the other polysulfide species in all examined experimental conditions. Additionally, the experimental values of Ea for the thermal degradation of polysulfide species correlate with the observed stability of the individual species; i.e., S22- has the highest Ea, followed by S32-.

A kinetic study of thioether synthesis under influence of ultrasound assisted phase-transfer catalysis conditions

Abstract: Alkyl bromides afford the corresponding sulfide derivatives upon treatment with aqueous sodium sulfide under phase-transfer catalysts (PTC) and ultrasound irradiation conditions. The use of phase-transfer catalysis and sonochemistry has been compared and demonstrated in these nucleophilic substitution reactions. The kinetics of the reaction depends on the effect of amount of catalyst, agitation speed, quaternary ammonium salts, amount of sodium sulfide, amount of sodium hydroxide, organic solvents, temperature and the frequency of the ultrasound waves on the conversion of alkyl bromides were investigated in detail. A kinetic model was built from which a pseudo-first order rate law is sufficient to describe the behavior of the reaction. The observed peculiar phenomena were also explained satisfactorily.

Syntheses of Novel Hexahomotrithiacalix[3]arenes

Abstract: The first synthesis of the C 3 -symmetrical p-tert-butylhexahomotrithiacalix[3]arene 7d via one-pot procedure by the reaction of 2,6-bis(chloromethyl)-p-tert-butylphenol 8d with sodium sulfide nanohydrate under high-dilution conditions is reported. Also, hexahomotrithiacalix[3]arenes 7d-f (where d-f designate the type of the substituents R at the p-positions of the phenolic rings: d, R=t-Bu; e, R=CH3; f, R=Cl) were synthesized via a convergent approach in good yield by the [2+1] cyclization reaction of 2,6-bis(chloromethyl)phenol monomers 8d-f and bis(chloromethyl)phenol dimers 15d-f in presence of sodium sulfide nanohydrate under high-dilution conditions. The structures of 7d-f were determined by 1H, 13C NMR, MS and elemental analysis. A preliminary study of the binding properties of 7d with alkali- and heavy metal cations using biphasic picrate extraction method showed only weak abilities to bind the cations examined.

Process for making desvenlafaxine

Abstract: Desvenlafaxine is formed from venlafaxine by the use of a demethylating agent comprising a metal sulfide, such as sodium sulfide, and optionally selenium

A simple synthesis of SnS nanoflakes at ambient conditions

Abstract: The present work reports a simple route to prepare tin monosulfide semiconductor nanocrystals at ambient conditions. In the presence of complexant L-tartaric acid, SnCl2·2H2O was dissolved in ethylene glycol (EG) solution. After adjusting the solution pH value, sodium sulfide dissolved in EG was added into the solution. The solution changed from colorless into brown immediately and phase-pure SnS, which was confirmed by powder X-ray diffraction (XRD) was produced. The transmission electron microscopic (TEM) investigation shows very thin rectangular flake like SnS crystals of 10∼20 nm in size.

Leaching of Celestite with Sodium Sulfide

Abstract: Leaching of celestite mineral, SrSO4, with sodium sulfide, Na2S, was investigated from the point of strontium carbonate, SrCO3, production. Experiments were carried out to explain the conversion mechanism of celestite to strontium disulfide, SrS2, in Na2S solution. Effects of stirring speed, particle size, and concentration of Na2S on conversion were studied at constant temperature and solid‐to‐liquid ratio. The results showed that the rate of conversion mainly depends on Na2S concentration. It was concluded that leaching of celestite in Na2S solution for conversion to SrS2 is possible but slow.

Method for treating copper-containing waste acid water

Abstract: The treatment method for copper-containing acid sewage comprises: treating the sewage with barium sulphide or sodium sulfide to prepare a plurality of chemical products, such as barium sulfate, and can recycle acid liquid with H+ content more than 16% as iron rust remover This invention has no pollution and well social and economic benefits

Method for obtaining nickel sulfide from pickled liquor of laterite nickel ore

Abstract: The invention provides a method to obtain nickel sulfide from pickle liquor of laterite nickel mine. Wherein, the leachate has pH value not less than 1.7 with nickel and sodium sulfide added for the mass ratio 1:3-8; mixing evenly, controlling the nickel ion concentration less than 0.02g/L and filtering; adding water into the residue with ratio for solid and liquid of 1:2, clearing, filtering and obtaining the product; then, neutralizing the filtrate to pH value as 2-4 for recycle or release. This method can obtain high-grade product and the nickel deposition rate can reach 99.5% or more.

The Zn- and Cd-Clusters of Recombinant Mammalian MT1 and MT4 Metallothionein Domains Include Sulfide Ligands

Abstract: Recombinant (E. coll) synthesis of mammalian MT1 and MT4 domains as separate peptides in Zn(II) and Cd(II) enriched growth media has rendered metal complexes containing sulfide anions as additional ligands. The Cd preparations show higher sulfide content than the Zn preparations. Also, the βMT1 and βMT4 fragments exhibit higher sulfide/peptide ratios than the respective α fragments. Titration of Zn3-βMT1 with Cd(II) followed by addition of several sodium sulfide equivalents shows that the Cd(II)-βMT1 species can incorporate sulfide ligands in vitro, with a concomitant evolution of their UV-vis and CD fingerprints to those characteristic of the Cd-S2- chromophores. Current results have also provided full understanding of previous data collected by this group in the characterization of the Cd-βMT1 preparations obtained from large-scale fermentor synthesis by allowing identification of at least 2S2- ligands per Cd-βMT1 species. Furthermore, the results here presented have revealed that synthesis of βMT4 in C...

Effects of sodium sulfide on burrowing activity of Capitella sp. I and bacterial respiratory activity in seawater soft-agar microcosms

Abstract: We applied the seawater soft-agar microcosm approach in order to reveal the effects of sodium sulfide on burrowing activity of Capitella sp. I and on bacterial respiratory activity on mucus-lined burrow. The presence of sodium sulfide up to 7 mM in the soft-agar was not detrimental to the burrowing activity and the survival of the worms, but seemed to enhance the secretion of mucus from the worms. Addition of INT into overlying water (0.01% v/v) of the soft-agar microcosms containing the same concentrations of sodium sulfide caused intensive deposition of INT-formazan in the water, on the mucus over soft-agar surface and on the burrow lining. Both image analyses and spectrophotometric determination of the red-color INT-formazan showed a marked increase in the presence of 3.5 mM sulfide. From these results, we concluded that sulfide can promote burrowing activity of Capitella sp. I and thus enhance the bacterial respiratory activity on the burrow lining. These findings will help clarify the possible interaction between Capitella worms and sulfur-oxidizing bacteria in organically-enriched, sulfide rich sediment in natural environments.

Combined Desulphurization and Denitrification Using Dielectric Barrier Discharge and Wet Reduction Technique

Abstract: Nitrogen oxides (NO + NO2) in most practical exhaust gases is mainly composed of NO. The injection of ozone, produced by dielectric barrier discharge, into the exhaust gas gives rise to rapid oxidation of NO into NO2. Once NO is converted into NO2, it can readily be reduced to N2 by a reducing agent in the next step. Sodium sulfide (Na2S) used as the reducing agent can also remove SO2 effectively, which makes it possible to treat NOx and SO2 simultaneously. The present two-step process through an ozonizing chamber and an absorber containing a reducing agent solution was able to remove about 95% of the NOx and 100% of the SO2, initially contained in the simulated exhaust gas. The formation of H2S from sodium sulfide was able to be suppressed by a basic reagent. The use of NaOH and CaCO3, together with the reducing agent not only prevented H2S from forming, but also cut down on the consumption of the reducing agent.

Method for separating copper, arsenic and zinc from copper-smelting high-arsenic flue dust sulphuric acid leach liquor

Abstract: The invention relates the method of separating copper, arsenic and zinc from copper smelting high arsenic fog sulfuric acid leachate, comprising the following steps: adding vulcanized agent (zine sulfide and arsenic sulfide) into the leachate to make copper precipitate, separating and getting the copper scale and copper liquid; concentrating the liquid and cooling, getting the zinc sulphate heptahydrate and crystallization mother liquid; adding sulfur dioxide into the crystallization mother liquid and getting arsenious oxide and the arsenic liquid; adding sodium sulfide aqueous solution into the arsenic liquid and getting the zine sulfide and arsenic sulfide which can be used as vulcanized agent to precipitate copper The core technology of the invention is copper precipitation by sulfidization At the process of the copper precipitation there is not other impurity substances and the vulcanized agent is made by the flow process The invention realizes the segregation of copper, arsenic and zinc and effectively harnesses the arsenic contamination

Method for preparing nanometer sulfides powder

Abstract: A process for preparing sulfide nano-particles includes such steps as preparing the solution of metal salt, adding quaternary ammonium salt, dripping the solution of sodium sulfide in it to generate deposit, filter, water washing, removing the ions of impurities, drying and calcining.

Fabrication of Magnetic Luminescent Nanocomposites via Adsorption-Precipitation of Metal Ions on Sulfonated Iron Oxide Nanoparticles

Abstract: A novel magnetic luminescent nanocomposite has been fabricated by the adsorption of CdII ions on the sulfonated Fe3O4 nanoparticles and the subsequent precipitation with sodium sulfide. The adsorpt...

Method of producing toltrazuril

Abstract: A preparation method of the Toltrazuril is provided. The Toltrazuril is the 1-[3-methyl-4-(4- Trifluoromethylthiobenzoxy) benzyl]-3-methyl-1, 3, 5, -triazine-2, 4, 6(1H, 3H, 5H)-trione. The methyl sulfide chloro compounds, fluoro-compounds, amides, phenol, methyl nitrate chlorobenzene, benzene aether, ammonia benzene aether, isonitrile acid ester and methyl urea from the reactions of 4-nitrochlorobenzene, sulfur, sodium sulfide and dimethyl sulfate. The detailed preparation is that reaction 1: the methanol of 410g and 4-nitrochlorobenzene of 158g are mixed and heated until soluble and are added with sulfur, sodium sulfide and methanol mixed liquor by drops, and kept for 2h under temperature of 60 DEG C. to 65DEG C.; reduce the temperature, add water of 880g and add dimethyl sulfate of 192g; during the period, the pH value of the sodium hydroxide is adjusted over 9, and the methyl sulfide of 153.6 is gained by filtering after reaction with yield of 91.1 per cent.

Production of pulp using a gaseous organic agent as heating and reaction-accelerating media

Abstract: The invention relates to an improved process to break down lignin macromolecules and liberating cellulose fibers in lignocellulosic material using delignifying reactants with a gaseous organic agent as a heating and reaction-accelerating media. Lignocellulosic material is first impregnated with reactant chemicals, e.g. commonly used agents such as sodium hydroxide and sodium sulfide. Subsequently, the energy required for the delignification reactions is provided through heating with a gaseous organic agent such as methanol or ethanol, condensing and releasing energy to the solid lignocellulosic material. The temperature during the heating step with a gaseous organic agent is higher than the temperature during the impregnation step.

Preparation method of inorganic fullerene molybdenum disulfide and its application

Abstract: An inorganic fullerene MoS2 nanoparticle with enclosed nested luminar structure used as the additive of lubricating oil is prepared through proportionally dissolving sodium sulfide and ammonium molybdate in water, reaction while adding the aqueous solution of polyethanediol, dripping hydrochloric acid to obtain MoS3 deposit, centrifugal separation, vacuum drying, hydrodesulfurizing at 500-1000 deg.C in quartz-pipe furnace under protection of Ar gas, and holding the temp for 5-10 hr.