Oxidation Of Bisulfite Research Articles

Bisulfite activated permanganate for oxidative water decontamination

Recently, bisulfite-activated permanganate (MnO4−; Mn(VII)) process has attracted considerable attention as a novel class of advanced oxidation technology for destruction of organic contaminants in water. However, disputes over the underlying activation mechanism as well as reactive species generated in the Mn(VII)/bisulfite system remain for a long period due to the fairly complex chemistry involved in this system. This article aims to present a critical review on scientific development of the Mn(VII)/bisulfite system, with particular focus on the generation and contribution of various reactive intermediates. Both reactive manganese species (RMnS) (i.e., soluble Mn(III), Mn(V), and Mn(VI)) and radical species (primarily SO4•−) are identified as the oxidizing components responsible for enhanced degradation of organic contaminants by the Mn(VII)/bisulfite system. Bisulfite plays a dual role of being an activating agent for reactive intermediates generation and acting as a complexing agent to stabilize RMnS. Solution chemistry (e.g., the [Mn(VII)]/[bisulfite] molar ratio, solution pH, the type of contaminants, ligands, and water matrix components) greatly impacts the generation and consumption of RMnS and radicals, thus influencing the degradation kinetics and pathways of organics. Particularly, dissolved oxygen (DO) is a vital factor for driving the oxidation of organics since the absence of DO can block the generation of SO4•− and meantime causes the consumption of RMnS by excess SO3•− as a strong reductant. Interestingly, ferrate (FeO42−, Fe(VI)) and hexavalent chromium (CrO42−/HCrO4−, Cr(VI)) that are high-valent metal oxyanions analogous to Mn(VII) can be activated by bisulfite via a similar pathway (i.e. both high-valent metal-oxo intermediates and reactive radicals are involved). Furthermore, key knowledge gaps are identified and future research needs are proposed to address the potential challenges encountered in practical application of the Mn(VII)/bisulfite oxidation technology.

Microbial sulfite oxidation coupled to nitrate reduction in makeup water for oil production

Bisulfite is used as an oxygen scavenger in waters used for oil production to prevent oxygen-mediated pipeline corrosion. Analysis of nitrate-containing water injected with ammonium bisulfite indicated increased concentrations of ammonium, sulfate and nitrite. To understand the microbial process causing these changes, water samples were used in enrichments with bisulfite and nitrate. Oxidation of bisulfite, reduction of nitrate, change in microbial community composition and corrosivity of bisulfite were determined. The results indicated that the microbial community was dominated by Sulfuricurvum, a sulfite-oxidizing nitrate-reducing bacterium (StONRB). Plating of the enriched StONRB culture yielded the bacterial isolate Sulfuricurvum sp. TK005, which coupled bisulfite oxidation with nitrate reduction to form sulfate and nitrite. Bisulfite also induced chemical corrosion of carbon steel at a rate of 0.28 ± 0.18 mm yr−1. Bisulfite and the generated sulfate could serve as electron acceptors for sulfate-reducing microorganisms (SRM), which reduce sulfate and bisulfite to sulfide. Nitrate is frequently injected to injection waters to contain the activity of SRM in oil reservoirs. This study suggests an alternative bisulfite injection procedure: Injection of nitrate after the chemical reaction of bisulfite with oxygen is completed. This could maintain the oxygen scavenger function of bisulfite and SRM inhibitory activity of nitrate.

Aqueous phase oxidation of bisulfite influenced by nitrate and its photolysis

Nitrate aerosol is ubiquitous in the atmosphere. Nitrate in the particulate and aqueous phase can affect various atmospheric chemical processes through its hygroscopicity and photolysis. The impacts of nitrate photolysis on the heterogeneous oxidation of SO2 have been attracting attention. However, the influence of nitrate on heterogeneous aqueous phase formation of atmospheric sulfate aerosol is still not very clear. In this study, the effects of nitrate on aqueous phase oxidation of bisulfite under different conditions were investigated. Results show that nitrate photolysis can promote the oxidation of bisulfite to sulfate, especially in the presence of O2. It is found that pH plays a significant role in the reaction, and ammonium sulfate has significant impacts on the enhancement of aqueous phase sulfate production through regulating the pH of solution. An apparent synergism is found among halogen chemistry, nitrate and its photochemistry and S (IV) aqueous oxidation, especially the oxidation of halide ions by nitrate and its photolysis and by the intermediate products produced by the free radical chain oxidation of S (IV) in acidic solution, leading to the coupling of the redox cycle of halogen with the oxidation of bisulfite, which promotes the continuous aqueous oxidation of bisulfite and the formation of sulfate. In addition, the role of nitrate itself in the aqueous phase oxidation of bisulfite is revealed. These results provide a new insight into the heterogeneous aqueous phase oxidation pathways and mechanisms of SO2 in cloud and fog droplets and haze particles.

Preparation of cellulose nanocrystals via successive periodate and bisulfite oxidation and mechanical and hydrophilic properties of the films

Microcrystalline cellulose was oxidized via periodate followed by sulfonation. The sulfonated cellulose nanocrystals were obtained through centrifugation, dialysis, and sonication. The sulfonated cellulose nanocrystals were rod-like and had an average length of 140 nm to 153 nm and an average width of 8 to 10 nm. The Fourier transform infrared profiles and polyelectrate titration demonstrated successful introduction of the sulfonated groups into the cellulose nanocrystals. The sulfonated cellulose nanocrystals had a higher crystallinity index than dialdehyde cellulose. The thin films fabricated via the casting of the sulfonated cellulose nanocrystals suspensions were highly hydrophilic.

Bifurcations induced by the electrode surface area during the electrochemical oxidation of bisulfite

Abstract Electro-oxidation behavior of bisulfite was found to depend qualitatively on the surface area of a glassy carbon electrode, where a transition from stable to oscillatory behavior took place as the surface area of the working electrode was increased to above a critical value. The size-dependent nonlinear behavior was observed at both potentiostatic and galvanostatic conditions. Preliminary characterization with electrochemical impedance spectroscopy illustrates the emergence of a hidden-negative differential resistance at the above threshold surface area. The conclusion that the studied system belongs to the class of HN-NDR type electrochemical oscillator is consistent with the result that oscillations also take place under a galvanostatic control.

Strong Enhancement of the Chemiluminescence of Hydrogen Sulfite-Oxidant Systems in the Presence of N,S-Doped Graphene Quantum Dots, and Its Application to the Determination of Folic Acid in Spinach and Kiwifruit Samples

The oxidation of bisulfite by classical oxidants such as hypochlorite, hydrogen peroxide, and permanganate is accompanied by weak chemiluminescence (CL). It is reported here that the CL is strongly enhanced in the presence of nitrogen/sulfur co-doped graphene quantum dots (N,S-GQD), nitrogen-doped graphene quantum dots (N-GQD), or graphene quantum dots (GQD). The weak CL of the NaHSO3-NaClO system and the NaHSO3-H2O2 system in the neutral medium and of the NaHSO3-KMnO4 system in acidic solution is more than 1000-fold enhanced in the presence of N,S-GQD, about sixfold in the presence of N-GQD, and twofold in the presence of GQD. Fluorescence spectra and CL spectra indicate that the N,S-GQD-sensitized enhancement originates from energy transfer and electron transfer annihilation effects on the CL system. It is also reported that folic acid (FA; vitamin B9) causes a notable diminution in the N,S-GQD-NaHSO3-NaClO system. Based on this finding, a sensitive CL method is developed for the determination of FA in food samples. The method works in the 0.5 to 70.0 μmol/L FA concentration range and the limit of detection is 78.0 nmol/L.

Qualitative dependence of the electro-oxidation behavior of sulfite on solution pH

Electrochemical oxidation of sulfite at a platinum electrode was investigated, in which changing the pH of supporting electrolytes caused qualitative changes in the oxidation behavior. In an acidic environment, oscillations in current were found to occur; however, only transient behavior was observed without the incorporation of an external resistor. Electrochemical impedance spectroscopic measurements indicate that the system possesses a region of negative differential resistance (NDR) at acidic conditions. To gain insights into the influence of pH, electrochemical oxidation of bisulfite was also studied, in which NDR was found, suggesting that changes in the dominant species induced by pH is responsible for the observed phenomena. Perturbation experiments illustrate the presence of bistability under galvanostatic conditions, lending support that the observed instabilities belong to the N-NDR class of electrochemical oscillators. Mass spectroscopic analysis and precipitation with barium ion suggest that SO42− is a major product of the electro-oxidation of sulfite.

Effects of oxygen and weak magnetic field on Fe(0)/bisulfite system: performance and mechanisms.

The performance and mechanisms of 4-nitrophenol (4-NP) degradation by the Fe(0)/bisulfite system were systematically investigated for the first time. The evidences presented in this study verified that O2 was a crucial factor that affected the mechanism of Fe(0)/bisulfite-driven 4-NP degradation. In the Fe(0)/bisulfite/O2 system, Fe(0) acted as a supplier of Fe(2+) to catalyze bisulfite oxidation that induced a chain reaction to produce reactive radicals for 4-NP degradation. While under N2 purging condition, bisulfite worked as a specified reductant that facilitated the transformation of Fe(3+) to nascent Fe(2+) ions, which principally accounted for the reductive removal of 4-NP. The application of a weak magnetic field (WMF) efficiently improved the removal rate of 4-NP and did not alter the mechanisms in both Fe(0)/bisulfite/O2 and Fe(0)/bisulfite/N2 processes. The secondary radicals, HO(·), SO4 (·-), and SO5 (·-), were considered as the most possible active oxidants contributing to the oxidative removal of 4-NP and even partial mineralization under an oxic condition. Compared with anoxic conditions, the performance removal of 4-NP by the WMF-Fe(0)/bisulfite/O2 system showed less pHini dependence. To facilitate the application of WMF-Fe(0)/bisulfite/O2 technology in real practice, premagnetization of Fe(0) was employed to combine with bisulfite/O2 and proved to be an effective and applicable method for 4-NP removal.

Influence of operating parameters on performance of SO2 absorption in fulvic acid solution

A novel process of flue gas desulfurization by aqueous fulvic acid (FA) solution with acid-base buffering capacity was developed. Experiments were carried out to investigate the influence of operating parameters such as the FA concentration, pH, temperature, gas flow rate, fly ash, O2, SO2 inlet concentration, CO2 and NO2 on SO2 absorption efficiency and Duration Time of High Efficiency (DTHE, the time of the SO2 absorption efficiency above 95%) in a lab-scale bubbling reactor. The results show high FA concentration has more absorption capacity for SO2, and the optimum concentration of FA solution is 0.08gmL−1, at which point the absorption efficiency is above 98%. The inlet SO2 concentration has little influence on absorption efficiency, but DTHE reduces with increasing inlet SO2 concentration. O2 has a little effect on absorption efficiency. The SO2 absorption efficiency is not affected by pH change in the range from 5.5 to 3.3, and maintained above 97.4%. Fly ash can improve SO2 absorption efficiency and DTHE. NO2 can accelerate the oxidation of bisulfite to sulfate and promote SO2 absorption. CO2 hardly influences on SO2 absorption efficiency, but the SO2 absorption capacity decreases with the increasing of CO2 partial pressure. Furthermore, the thermal stability and regenerability of FA were also evaluated by TG-DTG and XRD, respectively. The results demonstrate that FA with stable performances is a promising regenerative absorbent for the removal of SO2.

The Oxidation of Hydroxylamine on Gold Electrodes in Mildly Acidic Aqueous Electrolytes: Electrochemical and In Situ Differential Reflectance Studies

The oxidation of hydroxylamine (HAM) on polycrystalline Au electrodes has been examined in aqueous acetate buffer using electrochemical and in situ reflectance spectroscopic techniques. Cyclic voltammograms recorded under quiescent conditions in the potential region negative to the onset of Au oxidation were characterized by two clearly defined peaks centered at ca. and ca. versus SCE. Corresponding polarization curves obtained with a Au rotating disk electrode (RDE) as a function of rotation rate, ω, yielded two rather well defined plateaus. However, plots of the limiting currents, , versus √ω, and particularly of versus the concentration of HAM at fixed ω, were found to be non-linear pointing to complexities in the reaction mechanism. Experiments involving dual electrode techniques, including rotating ring-disk electrodes, afforded evidence that the two sequential redox waves are associated primarily with the oxidation of HAM to nitrite and nitrate, respectively. Normal incidence differential reflectance spectroscopy measurements, , on a Au RDE performed either at high ω or large [HAM] failed to detect the presence of Au oxide during HAM oxidation in the potential region in which Au is known to undergo oxidation. This behavior is analogous with that found earlier in our laboratories for the oxidation of bisulfite on Au.

Protein Radical Formation Resulting from Eosinophil Peroxidase-catalyzed Oxidation of Sulfite

Eosinophil peroxidase (EPO) is an abundant heme protein in eosinophils that catalyzes the formation of cytotoxic oxidants implicated in asthma, allergic inflammatory disorders, and cancer. It is known that some proteins with peroxidase activity (horseradish peroxidase and prostaglandin hydroperoxidase) can catalyze oxidation of bisulfite (hydrated sulfur dioxide), leading to the formation of sulfur trioxide anion radical ((.)SO(3)(-)). This free radical further reacts with oxygen to form peroxymonosulfate anion radical ((-)O(3)SOO(.)) and the very reactive sulfate anion radical (SO(4)()), which is nearly as strong an oxidant as the hydroxyl radical. However, the ability of EPO to generate reactive sulfur radicals has not yet been reported. Here we demonstrate that eosinophil peroxidase/H(2)O(2) is able to oxidize bisulfite, ultimately forming the sulfate anion radical (SO(4)()), and that these reactive intermediates can oxidize target proteins to protein radicals, thereby initiating protein oxidation. We used immuno-spin trapping and confocal microscopy to study protein oxidation by EPO/H(2)O(2) in the presence of bisulfite in a pure enzymatic system and in human promyelocytic leukemia HL-60 clone 15 cells, maturated to eosinophils. Polyclonal antiserum raised against the spin trap 5,5-dimethyl-1-pyrroline N-oxide (DMPO) detected the presence of DMPO covalently attached to the proteins resulting from the DMPO trapping of protein free radicals. We found that sulfite oxidation mediated by EPO/H(2)O(2) induced the formation of radical-derived DMPO spin-trapped human serum albumin and, to a lesser extent, of DMPO-EPO. These studies suggest that EPO-dependent oxidative damage may play a role in tissue injury in bisulfite-exacerbated eosinophilic inflammatory disorders.

Sulfite Oxidation Catalyzed by Cobalt Ions in Flue Gas Desulfurization Processes

This paper presents an experimental study of calcium bisulfite oxidation, a key step in the wet limestone-gypsum flue gas desulfurization (FGD) process, in the presence of catalysts (e.g., cobalt ions and a mixture of ferrous and cobalt ions). A fundamental approach is followed, by reproducing a simplified synthetic FGD liquor in which both catalyst ions, alone or mixed together, are present. A laboratory-scale apparatus is used, in which sulfurous solution is contacted with a gas phase at a fixed oxygen partial pressure (21.3 kPa) and at different temperature levels (25, 45, and 55 °C). The experimental results are analyzed using the theory of gas-liquid mass transfer with chemical reaction, showing that the slow reaction regime is explored and the transition from the kinetic to the diffusional subregime is identified. The experimental results are compared with those obtained in the presence of other catalytic species (manganese and ferrous ions), showing that cobalt is effective in catalyzing the oxidation of calcium bisulfite to sulfate, but to a minor extent with respect to iron and manganese.

Reactivities of NaOH Enhanced Iron Blast Furnace Slag/Hydrated Lime Sorbents toward SO2 at Low Temperatures: Effects of the Presence of CO2, O2, and NOx

The effects of the addition of NaOH on the reactivities toward SO2 of iron blast furnace slag/hydrated lime (BFS/HL) sorbents were studied without and with the presence of flue gas components, CO2, O2, and NOx, under the conditions prevailing in the bag filters of dry and semidry flue gas desulfurization processes. The reactivities of sorbents were markedly enhanced by the addition of NaOH when CO2, O2, and NOx were not present in the gas mixture. The enhancement effect mainly resulted from the deliquescent property of NaOH. With the presence of CO2, O2, and NOx at their typical concentrations in the flue gas, the sorbent reactivity was greatly increased due to the oxidation of bisulfite and sulfite ions to sulfate ions as well as the formation of deliquescent salts, calcium nitrite and nitrate, being enhanced by the presence of NO2 during the sulfation of a BFS/HL sorbent. The addition of NaOH in this case promoted the formation of sulfates but became less important in raising the sorbent reactivities for sorbents except BFS. Without the presence of CO2/O2/NOx, the BFS/HL sorbents with ratios ≤70/30 had higher reactivities than HL, but with the presence of CO2/O2/NOx, HL had the highest value of SO2 capture among the BFS/HL and BFS/HL/NaOH sorbents tested. Placing the SO2 removal unit before the NOx removal unit in practical operations can take advantage of the enhancement effect of CO2/O2/NOx on increasing the Ca utilization and SO2 capture of the sorbent.

Reaction rate of sulfite oxidation catalyzed by cuprous ions

Wet limestone scrubbing is one of the most widely used flue gas desulfurization processes for control of sulfur dioxide emissions from combustion of fossil fuels. A key step in the process is forced oxidation in the scrubber loop, which substantially improves the dewatering properties of the sludge, leading to the formation of gypsum (CaSO4·2H2O). This paper deals with the experimental study of calcium bisulfite oxidation in the presence of catalysts (ferrous and cuprous ions) added to the reaction vessel. A laboratory-scale apparatus was used; the experiments were performed at a fixed oxygen partial pressure (21.3 kPa) and at a temperature of 45 °C. In particular, the effect of the simultaneous addition of both catalysts has been studied. The analysis of the experimental results, carried out by using the theory of mass transfer with a chemical reaction, indicates that the slow reaction regime has been explored, and the transition from the kinetic to the diffusional sub-regime has been reached. Experimental results have been compared with those obtained in the presence of the single catalytic species (Cu+ alone and Fe2+ alone), showing that copper is less effective than iron as a catalyst; no synergy between the two catalysts added simultaneously has been observed.

Kinetic and reaction mechanisms of calcium bisulfite catalytic oxidation

In this paper, the oxidation of calcium bisulfite in the presence of ferrous ions as a catalyst is studied in a laboratory scale apparatus at a fixed oxygen partial pressure (21.3 kPa) and at a temperature of 45 °C. The analysis of the experimental results, carried out by using the theory of mass transfer with chemical reaction, indicates that the slow reaction regime has been explored, and the transition from the kinetic to the diffusional subregime identified. A kinetic analysis allows to develop a reaction rate equation, assuming that the bisulfite oxidation in the presence of ferrous ions follows a parallel reaction mechanism; the resulting overall reaction rate has been found to be of first order with respect to ferrous ion concentration and of three halves with respect to bisulfite concentration. Moreover, the catalytic effect of ferrous ions has been compared with that of manganese ions previously studied, showing that ferrous is a catalyst more active than manganese.

Calcium Bisulfite Oxidation in the Flue Gas Desulfurization Process Catalyzed by Iron and Manganese Ions

Among different flue gas desulfurization processes for control of sulfur dioxide emissions from combustion of fossil fuels, wet limestone scrubbing is the most widely used. Forced oxidation in the scrubber loop substantially improves the dewatering properties of the sludge, leading to the formation of gypsum (CaSO4·2H2O). In view of this, the present paper reports the experimental study of calcium bisulfite oxidation in the presence of catalysts (ferrous and manganese ions) both separately and simultaneously added in the reaction vessel. A laboratory-scale apparatus was used; the experiments were performed at a fixed oxygen partial pressure (21.3 kPa) and at a temperature of 45 °C. In particular, the effect of the simultaneous addition of both catalysts has been studied. The analysis of the experimental results, carried out by using the theory of mass transfer with chemical reaction, indicated that the slow reaction regime has been explored and the transition from the kinetic to the diffusional subregime ...

Bisulfite Oxidation Reaction Rate in a Bubbling Tank

In wet limestone gypsum Flue Gas Desulfurizers, flue gas is washed with CaCO 3 -water slurry on the wet walls of a vertical absorption tower, where SO 2 and O 2 are absorbed to form CaSO 3 and CaSO 4 . Though it is required to capture sulfur into calcium sulfate, which is neutral to the environment as deposited, CaSO 3 is not always oxidized completely there to CaSO 4 due to insufficient residence time of slurry on the wet walls and the low absorption rate of oxygen. The rest CaSO 3 should be oxidized in a bubbling tank just under the tower. Therefore appropriate air bubble injectors are required to supply oxygen, just as much as necessary and enough, into the slurry in the tank. Here is proposed an Air Rotary Sparger (ARS) for the vertically and horizontally uniform distribution of small air bubbles in the tank and its performance is investigated with a small-sized conventional paddle type model with a central air injection hole on the bottom and two ARS models.

Enhancement of the growth of Helicobacter pylori in Brucella broth by hydrogen peroxide.

We found that a sub-lethal concentration of hydrogen peroxide (HPOx) enhanced the growth of Helicobacter pylori in Brucella broth supplemented with 10% fetal bovine serum (BB/FBS). The enhancement was evident at 0.1 mM HPOx and reached a maximun at 3.5 mM. The growth stimulation was dependent on the basal media used; when brain heart infusion broth (BHIB) was used instead of BB, the growth was not altered regardless of the presence or absence of HPOx. Furthermore, the growth in BHIB/FBS was comparable to that in BB/FBS plus 3.5 mM HPOx. This suggested that the enhancement of growth by HPOx resulted from the derepression of the inhibitory factor existing in BB by HPOx. The inhibitory substance seemed to be bisulfite salt since the bacteria grew to a similar extent in bisulfite-less Brucella broth (BLBB0)/FBS compared to the bacterial growth in BHIB/FBS and BB/FBS plus HPOx. These results indicate that the detoxification of bisulfite in BB can be easily achieved by simply adding HPOx to the medium, which causes the oxidation of bisulfite to bisulfate, a less-toxic compound to the bacterial growth. Since we also found that the morphology and cellular protein profile of BB/FBS-cultured bacteria were apparently different from those cultured in BLBB/FBS, we propose that the use of BB for primary isolation and cultivation of H. pylori should be limited on certain occasions, or if necessary, BB can be used after detoxification of the bisulfite by the addition of a low concentration of HPOx.

Catalytic oxidation of calcium bisulfite in the wet limestone–gypsum flue gas desulfurization process

A study on the oxidation of calcium sulfite catalyzed by Mn 2+ is presented in this paper. A laboratory-scale well-mixed thermostated reactor was used, with continuous feeding of both gas and liquid phase. The gas phase was a mixture of oxygen and nitrogen, with O 2 partial pressure varying from 5.1 to 40.5 kPa. The liquid phase was obtained by mixing inside the reactor two separate aqueous solutions, one obtained by dissolving Ca(OH) 2 into a SO 2 solution, and the other one containing manganous sulfate. The temperature was kept constant in all the experiments at 45°C. The results show that increasing catalyst concentration, the transition takes place from slow kinetic to slow diffusional and eventually to fast reaction regime.

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).