Bisulfite Ion Research Articles

Kinetics of oxygen exchange between the two isomers of bisulfite ion, disulfite Ion (S(2)O(5)(2-)), and water as studied by oxygen-17 nuclear magnetic resonance spectroscopy.

The nuclear magnetic transverse relaxation time of oxygen-17 in aqueous sodium bisulfite solutions in the pH range from 2.5 to 5 was measured over a range of temperatures, pH, and S(IV) concentrations at an ionic strength of 1.0 m. From these data the rate law for oxygen exchange between bisulfite ion and water was determined and found to be consistent with oxygen exchange occurring via the reactions SHO(3)(-) + H(+) SO(2) + H(2)O, SO(3)H(-) + SHO(3-) SO(3)(2-) + SO(2) + H(2)O, and SO(3)H(-) + SHO(3-) S(2)O(5)(2-) + H(2)O, where the symbol SHO(3-) refers to both isomeric forms of bisulfite ion, one in which the hydrogen is bonded to the sulfur (denoted HSO(3-)) and another in which the hydrogen is bonded to an oxygen atom (denoted SO(3)H(-)). The SO(3)H(-) isomer exchanges oxygen atoms with water much more rapidly than does the HSO(3-) isomer. The value of k(-1) was determined and is in essential agreement with the results of a previous determination by relaxation measurements. The value of k(16a) + k(16b) was also found, and k(16b) is at least as large as k(16a). The rate and mechanism of oxygen exchange between the two bisulfite ion environments were studied by analyzing the broadening of the HSO(3-) resonance. Oxygen exchange occurs through isomerization caused by proton transfers.

Infrared spectroscopy of SO 2 aqueous solutions

The chemistry of SO 2 solutions was studied with infrared transmission and total internal reflection (ATR) spectroscopy. The cross-sections of the SO 2 stretching vibrations ν 1, ν 3 and the combination band of ν 1+ ν 3 were obtained and found to be slightly different from their gas phase values. Six features we associate with sulfur-containing ions were observed. We present the first infrared evidence for the bisulfite ion HOSO 2 − through detection of its OH stretching vibration. Other features may be associated with HSO 3 −, another isomer of the bisulfite ion, and a new compound we propose to be H 2S 2O 6 2−. We found no evidence for sulfurous acid H 2SO 3.

Glycerol production by microbial fermentation: A review

Microbial production of glycerol has been known for 150 years, and glycerol was produced commercially during World War I. Glycerol production by microbial synthesis subsequently declined since it was unable to compete with chemical synthesis from petrochemical feedstocks due to the low glycerol yields and the difficulty with extraction and purification of glycerol from broth. As the cost of propylene has increased and its availability has decreased especially in developing countries and as glycerol has become an attractive feedstock for production of various chemicals, glycerol production by fermentation has become more attractive as an alternative route. Substantial overproduction of glycerol by yeast from monosaccharides can be obtained by: (1) forming a complex between acetaldehyde and bisulfite ions thereby retarding ethanol production and restoring the redox balance through glycerol synthesis; (2) growing yeast cultures at pH values near 7 or above; or (3) using osmotolerant yeasts. In recent years, significant improvements have been made in the glycerol production using osmotolerant yeasts on a commercial scale in China. The most outstanding achievements include: (1) isolation of novel osmotolerant yeast strains producing up to 130 g/L glycerol with yields up to 63% and the productivities up to 32 g/(L day); (2) glycerol yields, productivities and concentrations in broth up to 58%, 30 g/(L day) and 110–120 g/L, respectively, in an optimized aerobic fermentation process have been attained on a commercial scale; and (3) a carrier distillation technique with a glycerol distillation efficiency greater than 90% has been developed. As glycerol metabolism has become better understood in yeasts, opportunities will arise to construct novel glycerol overproducing microorganisms by metabolic engineering.

Dominant factors of major and minor components and formation of hydroxyalkanesulfonate in urban dew-water

Dew-water was collected from January 1999 to February 2000 in Yokohama, Japan and analyzed for not only soluble major components but also insoluble or trace components. The pH of dew-water ranged from 5.36 to 6.71 and volume-weighted average pH was 5.81. In dew-water, Si, Al, Fe, Cl, and Na were abundant and they were confirmed to be transported from natural sources, sea and soil dust. The concentrations of Si, Al, Fe, and Ti contained in coarse mode aerosol were several times higher in dew-water than those in rain-water, while the concentrations of V and Pb contained in fine mode aerosol were about the same level to each other. Besides these elements derived from aerosol, the elements derived from gaseous species are also major components in dew-water. The high concentration of weak acid is one of the significant characteristics of dew-water. Bisulfite ion in dew-water is the important species as the precursor of the sulfate ion but it is stable by forming hydroxyalkanesulfonate (HASA). The HASA concentrations were evaluated by using concentrations of total S(IV) and aldehydes and hydroxymethanesulfonate (HMSA) was shown to be the dominant species in S(IV).

Elimination of the interferences by keto-opiates in the GC-MS analysis of 6-monoacetylmorphine.

A simple procedure to eliminate the interference from keto-opiates in the analysis of 6-monoacetylmorphine (6-MAM) by gas chromatography-mass spectrometry is described. The pretreatment of urine samples with sodium bisulfite followed by solid-phase extraction results in the elimination of the bisulfite addition products formed from the reaction of the bisulfite ions with the carbonyl carbon of the keto-opiates. This simple procedure results in the accurate quantitation of 6-MAM at a concentration of 4 ng/mL in the presence of keto-opiates up to 10,000 ng/mL.

Calcium Bisulfite Oxidation Rate in the Wet Limestone−Gypsum Flue Gas Desulfurization Process

In this paper oxidation of calcium bisulfite in aqueous solutions was studied, in connection with the limestone−gypsum flue gas desulfurization process. Experimental measurements of the oxidation rate were carried out in a laboratory scale stirred reactor with continuous feeding of both gas and liquid phase. A calcium bisulfite clear solution was used as liquid phase, and pure oxygen or mixtures of oxygen and nitrogen were used as gas phase. Experiments were carried out at T = 45 °C varying the composition of the liquid phase and the oxygen partial pressure. Manganous sulfate was used as catalyst. The analysis of the experimental results showed that the kinetics of bisulfite oxidation in the presence of MnSO4 follow a parallel reaction mechanism, in which the overall reaction rate can be calculated as the sum between the uncatalyzed rate (3/2 order in bisulfite ion) and the catalyzed reaction rate (first order in manganous ion).

The Influence of Air Pollution on the Concentration of Airborne Elements and on the Production of Stress-Ethylene in the Lichen Usnea hirta (L.) Weber em. Mot. Transplanted in Urban Sites in Oulu, N. Finland

The purpose of the present study was to examine theresponse, as indicated by the production of stress-ethylene, of the lichenUsnea hirta, to a buffered acidic solution and to a solutioncontaining bisulfite ion, both at pH 4.0. In addition, the study investigatedthe accumulation capacity of U. hirta transplanted either to thevicinity of two streets with slow traffic, or to the vicinity of a highway inthe city of Oulu, N. Finland for a short period (45 d), and to analyze thecomparative production of stress-ethylene and the amounts of airborneelements accumulated in the thallus. Thalli of U. hirta manifested ahigh accumulation capacity for K, Ca, Na, Mg, Fe, Zn, and Mn in samplesexposed in one of the two streets with slow traffic in Oulu, in comparisonwith thalli left at the control site in the forest outside of the city. Twoof the observed elements, Pb and Ca, exhibited a positive correlation withthe concentration of ethylene detected consecutive to the treatment of lichenthalli with H2O (pH 6.8). The concentrations of stress-ethylene inlichen thalli retrieved from the streets with slow traffic and less cars(14,000 per day), soaked in solutions of NaHSO3 (pH 4.0), werehigher than those produced by thalli retrieved from a site near the highway(with 25,000 cars per day) and by thalli left in the forest. It is suggestedthat the streets with slow traffic and less cars are more polluted than thehighway as a result of bad ventilation conditions and a slow rate ofdispersion of airborne pollutants.

An ab initio study of the structure and energetics of the bisulfite ion in the gas phase and in aqueous solution

Ab initio molecular orbital methods, employing large basis sets and the MP2, B3LYP and BD(T) correlation approaches, have been used to study the two low energy isomers of bisulfite (HSO 3 −) in the gas phase and in aqueous solution. Explicit solvation is found to be essential to predict the correct order of isomer stability and yields an excellent prediction of the relative energies of the C 1 and C 3 v forms. The effect of explicit solvent on molecular geometry must be included to allow accurate prediction of the observed NMR shifts, which are calculated using the GIAO method. The vibrational frequencies are also calculated. The results of our study are discussed in terms of the role of bisulfite in the atmospheric oxidation of SO 2.

In-situ radiotracer studies of sorption processes in solutions containing (bi)sulfite ions—II. Low carbon steel

In this paper, time, potential and pH dependence of SO 4 2− and HSO 3 − accumulations measured by an in-situ radiotracer method on surface oxide layers of low carbon steel are presented and discussed. This work is a continuation of a research program[1–5] and deals with the characterization of the sorption behaviour of low carbon steel in solutions containing sulfate and bisulfite ions (as a possible model of acid rain). From the experimental results it can be stated that 1. (i) the presence of bisulfite ions in the solution phase accelerates the corrosion of low carbon steel; 2. (ii) at E > 0.40 V the electrooxidation of HSO 3 − ions presumably proceeds to yield a steel surface covered with oxidation products ( eg sulfate, dithionate[1]); 3. (iii) surface excess values of SO 4 2− and HSO 3 − ions (as well as the oxidized and reduced adspecies of bisulfite) are very high (up to Γ = 6 × 10 −8 and Γ = 1 × 10 −8 mol cm −2, respectively) ie, a significant incorporation of aggressive ions into the surface oxide layers occurs; 4. (iv) the strong embedding of anions studied is probably the result of some selective chemical interactions (chemisorption) of the above species with active sites involved in the steel surface undergoing structural transformation.

Oxidation of Aqueous Sulfur Dioxide Catalyzed by Poly-4-vinylpyridine-Cu(II) Complex. Part 1: Homogeneous Phase Oxidation

The oxidation of aqueous sulfur dioxide in the presence of polymer-supported copper(II) catalyst is also accompanied by homogeneous oxidation of aqueous sulfur dioxide catalyzed by leached copper(II) ions. Aqueous phase oxidation of sulfur dioxide of low concentrations by oxygen in the presence of dissolved copper(II) has therefore been studied. The solubility of SO2 in aqueous solutions is not affected by the concentration of copper(II) in the solution. In the oxidation reaction, only HSO is the reactive S(IV) species. Based on this observation a rate model which also incorporates the effect of sulfuric acid on the solubility of SO2 is developed. The rate model includes a power-law type term for the rate of homogeneous phase reaction obtained from a proposed free-radical chain mechanism for the oxidation. Experiments are conducted at various levels of concentrations of SO2 and O2 in the gas phase and Cu(II) in the liquid phase. The observed orders are one in each of O2, Cu(II) and HSO. This suggests a first-order termination of the free radicals of bisulfite ions.

Oxidation of Aqueous Sulfur Dioxide Catalyzed by Poly-4-vinylpyridineCuII Complex. Part 1: Homogeneous Phase Oxidation

The oxidation of aqueous sulfur dioxide in the presence of polymer-supported copper(II) catalyst is also accompanied by homogeneous oxidation of aqueous sulfur dioxide catalyzed by leached copper(II) ions. Aqueous phase oxidation of sulfur dioxide of low concentrations by oxygen in the presence of dissolved copper(II) has therefore been studied. The solubility of SO2 in aqueous solutions is not affected by the concentration of copper(II) in the solution. In the oxidation reaction, only HSO is the reactive S(IV) species. Based on this observation a rate model which also incorporates the effect of sulfuric acid on the solubility of SO2 is developed. The rate model includes a power-law type term for the rate of homogeneous phase reaction obtained from a proposed free-radical chain mechanism for the oxidation. Experiments are conducted at various levels of concentrations of SO2 and O2 in the gas phase and Cu(II) in the liquid phase. The observed orders are one in each of O2, Cu(II) and HSO. This suggests a first-order termination of the free radicals of bisulfite ions.

Uncatalyzed heterogeneous oxidation of calcium bisulfite

Wet limestone scrubbing is the most common flue gas desulfurization process for control of sulfur dioxide emissions from combustion of fossil fuels. Forced oxidation in the scrubber loop improves the dewatering properties of the sludge, leading to the formation of gypsum (CaSO 4·2H 2O). A literature analysis revealed that uncertainties on the mechanisms of the oxidation reaction and on the values of the kinetic parameters still remain. In the present work the oxidation rate was experimentally studied by contacting pure oxygen or mixtures of oxygen and nitrogen with a calcium bisulfite solution. The experiments were carried out in a well-mixed bubbling reactor varying temperature, oxygen partial pressure and sulfite concentration, in the absence of solid calcium sulfite and of catalytic species. It was shown that the rate of the process is controlled by reaction kinetics, and that the reaction rate is zero order in dissolved oxygen and 3 2- order in bisulfite ion.

Kinetics and Mechanism of the Oxidation of HSO3- by O2. 2. The Manganese(II)-Catalyzed Reaction

The Mn2+-catalyzed oxidation of HSO3- by O2 has been studied in the pH region 4.5 and at bisulfite ion concentrations from 1.5 × 10-3 to 1.2 × 10-2 M. The reaction was found to obey a three-term rate law: −d[O2]/dt = kα[HSO3-]2 + kβ[HSO3-][Mn2+] + kγ[Mn2+]2 with kα = 3.6 × 10-3 M-1 s-1, kβ = 1.23 M-1 s-1, and kγ = 98.6 M-1 s-1 at pH 4.50, 25 °C, and ionic strength 0.050 M. The kinetic behavior of the reaction resembles markedly that of the uncatalyzed reaction. The rate of the reaction is independent of oxygen concentration, S2O72- and HSO5- are intermediates in the reaction, and the reaction is catalyzed by S2O82- and strongly inhibited by methanol. The experimental results can be quantitatively explained by the addition to the uncatalyzed reaction mechanism of a chain propagation reaction involving Mn2+ and SO5•-. Among several alternatives, the manganese propagation may be represented as follows: (I) Mn2+ + SO5•- → Mn(III) + HSO5-; (II) Mn(III) + HSO3- → Mn2+ + SO3•-. The resulting mechanism leads to the three-term rate law where the first term is the uncatalyzed rate and the second term can be predicted quantitatively from the uncatalyzed rate and the last term. It was inferred from the yield of S2O72- that, unlike the reaction between SO5•- and HSO3-, there is little or no branching of the first reaction to form the SO4•- radical. The ratio of the rate constant of (I) to that of the reaction of SO5•- with HSO3- in the uncatalyzed reaction mechanism has been determined to be 124. The quantitative agreement between the experimental data and predictions for the effect of S2O82- has substantiated the validity of the proposed mechanism. The pH dependence of the reaction rate can be almost entirely accounted for by the pH dependence of the reaction between HSO5- and HSO3-, indicating that reaction I is independent of the hydrogen ion concentration in the pH region studied. While methanol inhibits the reaction, the quantitative discrepancy between predictions and experiments suggests that the reactions with alcohols are more complex than previously thought. Further work in this area is needed to understand fully the reaction mechanism when alcohol is present.

Initial Interaction of Sulfur Dioxide with Water Covered Metal Surfaces: An In Situ IRAS Study

In situ infrared reflection absorption spectroscopy (IRAS) has been used to study the initial interaction of sulfur dioxide with water adlayer covered copper, nickel, and zinc surfaces. Each metal was exposed to 0.21 ppm in flowing air at 80% relative humidity and the formation of sulfite was followed from submonolayer thickness to layers of corrosion products of a few nanometers thickness. From the positions of sulfite bands in the experimentally obtained IRAS spectra and from considerations of optically induced bandshifts in calculated IRAS spectra, it is suggested that the sulfite ions are coordinated with sulfur or sulfur and oxygen to the copper surface and with oxygen to the nickel and zinc surfaces. A fast initial growth rate was observed for the sulfite layer, which was followed by a slower growth rate after a few hours of exposure. A reaction sequence is suggested where bisulfite ions, formed by hydrolysis of sulfur dioxide in the water adlayer, generate surface metal‐sulfito complexes at the oxide covered metal surface which subsequently detach from the surface and precipitate as thin layers of corrosion products.

Keto–enol tautomerism and hydration of 9-acylfluorenes

Keto-enol tautomeric constants and ionisation constants have been measured for the keto and enol tautomers of 9-formyl-, 9-acetyl- and 9-benzoyl-fluorene in aqueous solution at 25 °C. Values of pKE(KE=[enol]/[ketone] and pKE=–log KE) are –1.22, 2.28 and 1.91, respectively, and the corresponding pKas for enolate anion formation are 6.19, 9.94 and 9.44 for the keto tautomers and 7.41, 7.66 and 7.53 for the enols. The measurements demonstrate the effectiveness of the fluorenyl group in increasing enol stability and ketone acidity. For 9-formylfluorene, for which the enol is the stable tautomer, KE is increased by a factor of more than 107 and the acidity of the keto tautomer by more than 109 relative to acetaldehyde (pKE= 6.17, pKa= 16.73). For 9-acetyl- and 9-benzoyl-fluorenes tautomeric constants were determined kinetically by combining rate constants for ketonisation measured spectrophotometrically following quenching of their enolate anions in carboxylic acid buffers with rate constants for enolisation measured by halogen trapping under the same conditions. For 9-formylfluorene rate constants for enolisation were measured by generating its unstable aldehyde tautomer from an ethanethiol hemithioacetal by reaction with iodine. Combining these rate constants with rate constants for ketonisation from trapping the aldehyde with bisulfite ion gave the tautomeric constant. In aqueous solution the aldehyde tautomer of 9-formylfluorene is appreciably hydrated and an equilibrium constant Kh=[hydrate]/[aldehyde]= 5.6 was derived from measurements of the (slower) equilibration of enol and hydrate following enolisation in acetic acid buffers. In aqueous solution therefore the enol (71%) and hydrate (24%) are the principal species. log k-pH profiles for enolisation, ketonisation and hydration reactions are reported. Intrinsic reactivities of the three enolate anions towards protonation by H3O+ and carboxylic acids are compared within an extended Bronsted plot of log k versusΔpK with measurements by Kresge for the corresponding enolate anions derived from fluorene-9-carboxylic acid and its methyl, methylthio and methylthione esters. Surprisingly, not only are the thin and thione esters less acidic than the oxygen ester, but intrinsically less reactive.

Free-radical aqueous slurry polymerizations of acrylonitrile: 2. End-groups and other minor structures in polyacrylonitriles initiated by potassium persulfate/sodium bisulfite

Polyacrylonitriles prepared by aqueous free-radical slurry polymerization using the potassium persulfate/sodium bisulfite redox initiation system have been examined by FT i.r. and high-field 13C and 1H n.m.r. spectroscopy. They have been shown to contain predominantly sulfonate and non-sulfur containing end-groups derived principally from initiation by bisulfite radicals and transfer to the bisulfite ion. Some sulfate end-groups are present also, although in much smaller amounts than the sulfonate end-groups, and are believed to arise from initiation by sulfate radical anions. In these respects, the polymers resemble closely those made by using ammonium persulfate/sodium metabisulfite as the initiator system.

Sensitivity of Iron-Oxidizing Bacteria, Thiobacillus ferrooxidans and Leptospirillum ferrooxidans , to Bisulfite Ion

When grown on iron-salt medium supplemented with the bisulfite ion, Leptospirillum ferrooxidans was much more sensitive to the ion than was Thiobacillus ferrooxidans. The causes of the sensitivity of L. ferrooxidans to the bisulfite ion were studied. The bisulfite ion completely inhibited the iron-oxidizing activities of L. ferrooxidans and T. ferrooxidans at 0.02 and 0.2 mM, respectively. A trapping reagent for the bisulfite ion, formaldehyde, completely reversed the inhibition. The treatment of intact cells with 1.0 mM bisulfite ion for 1 h and washing the bisulfite ion from the cells had no harmful effects on the iron-oxidizing activity of T. ferrooxidans. However, the treatment of L. ferrooxidans with 0.1 mM bisulfite ion for 1 h completely destroyed the iron-oxidizing activity. T. ferrooxidans had sulfite:ferric ion oxidoreductase activity. In contrast, a quite low level of sulfite:ferric ion oxidoreductase activity was found in L. ferrooxidans, suggesting that it is much more difficult for L. ferrooxidans to oxidize the bisulfite ion to the less harmful sulfate than it is for T. ferrooxidans. These results suggest that the sensitivity of L. ferrooxidans to the bisulfite ion is due to a lack of an active sulfite:ferric ion oxidoreductase and the sensitivity of its iron oxidase to bisulfite ion.

Inhibition of Iron-oxidizing Activity by Bisulfite Ion inThiobacillus ferrooxidans

Growth of Thiobacillus ferrooxidans on iron- and sulfur-salts media and iron oxidizing activity of this bacterium were strongly inhibited by bisulfite ion. The mechanism of inhibition by bisulfite ion of iron-oxidizing activity was studied with the plasma membrane of T. ferrooxidans AP19-3. The c-type cytochrome in the plasma membrane was reduced by ferrous ion and the cytochrome reduced by Fe2+ was oxidized by cytochrome c oxidase in the plasma membrane. In contrast, c-type cytochrome was reduced by bisulfite ion, but it was not oxidized by cytochrome c oxidase in the membrane. Cytochrome c-oxidizing activity was also inhibited by the ion when mammalian cytochrome c was used as an electron donor, suggesting that cytochrome c oxidase, one of the component of iron oxidase, is the site of inhibition by bisulfite ion.

Structures and relative stabilities of bisulfite ion isomers

The structure and equilibria of the bisulfite ion in the gas phase are investigated using ab initio electronic structure methodology. The structures analysed were the C 3v structure and the syn and anti tautomers of the C s structure. Optimized geometries and total energies were determined for a variety of basis sets and levels of theory. Polarization functions had profound effects on both geometries and relative energies. Addition of diffuse functions was found to affect significantly both relative stabilities and geometries at the MP2/3–21 + G ∗ level. However, diffuse functions had minor effects at the MP2/6–31 + G ∗ level. Inclusion of electron correlation via second-order (MP2) and full fourth-order (MP4SDTQ) Møller-Plesset perturbation treatments was found to have moderate effects on geometries and relative stabilities. Normal mode vibrational frequencies were calculated for all isomers studied. The lowest energy structure was found to be an asymmetric form of the syn conformation of the C s tautomer.

Free-radical aqueous slurry polymerizations of acrylonitrile: 1. End-groups and other minor structures in polyacrylonitriles initiated by ammonium persulfate/sodium metabisulfite

Polyacrylonitriles prepared by aqueous free-radical slurry polymerization at 40°C using ammonium persulfate and sodium metabisulfite as redox initiator have been examined by FTi.r. and by high-field 13C and 1H n.m.r. They have been shown to contain small quantities of acrylamide and acrylic acid units and to possess predominantly sulfonate and non-sulfur containing end-groups derived principally from transfer to bisulfite ion during the polymerization. Other end-groups present in low concentration are sulfate and hydroxyl; the former probably arises from initiation by sulfate radical anions and the latter either from transfer to water or by adventitious hydrolysis of some of the sulfate end-groups. Because they contain few groups capable of initiating intramolecular cyclization, the polyacrylonitriles are white with no sign of discoloration.