TECHNOLOGICAL STUDY OF MAGNESIUM BISULFITE KENAF PULP

How to produce bisulfite pulp by kenaf mesta is studied in this paper. After the stalk, the phloem, the xylem of kenaf were analyzed and a series of experiments, the result was gotten as follows: TA 5.6%, temperature 160℃,heat preservation time 120min,CA/FA 1.5, liquor ratio 1:5, and the yield of screened pulp 48.3%, kappa number 42.1, viscosity 948.6ml/g, brightness 51.4% ISO.

Wheat Grain Yield and Protein Content as Influenced by Sodium Bisulfite

Two wheat varieties with similar yield and significantly different protein content were chosen to study the effect of foliage spraying sodium bisulfite (NaHSO3) at low concentration to wheat plants receiving different levels of nitrogen on nitrate reduction along with yield and protein content of grain, so as to discuss the relationship between carbon metabolism and nitrogen metabolism, and find out the intrinsic mechanism of grain yield and protein content formation. The results showed that spraying NaHSO3 at grain-filing stage increased the yield of grain, but declined the capacity of nitrate reduction, which might result in decrease of protein content in the end. Whether receiving NaHSO, or not, the variety with high protein content had higher final protein level and nitrate reduction capacity than that with low protein content.

Nitric Oxide: Probably the <i>in Vivo</i>Mediator of the Bisulfite’s Effects

The use of bisulfite in food and beverage preservation, as well as in commercial goods and pharmaceuticals as antimicrobial agents is well known, but not very much is reported on its action in vivo. It has been stressed that its action is connected to the presence of NO, and the only reported/ hypothesized evidence concerns the possible interaction with GSNO (S-nitrosoglutathione), an NO releaser. In this light, we investigated the interaction between GSNO and the bisulfite in an aqueous medium at pH = 6.4;actually, a positive effect of the sulfite was evidenced. i.e., the S-nitrosoglutathione becomes a more efficient NO-releaser. But, the nitrite is the real pool of NO in vivo, therefore we investigate its interaction with the bisulfite in an aqueous acidic solution at pH = 6.4;this time, a definitely efficient and abundant NO release, 3.61 times higher compared to the GSNO, has been evidenced. Therefore, these results allow hypothesizing a fundamental role of NO in the bisulfite’s action in vivo, or most probably the bisulfite acts simply as cofactor of NO-releasers.

The bisulfite genomic sequencing protocol

The bisulfite genomic sequencing (BGS) protocol has gained worldwide popularity as the method of choice for analyzing DNA methylation. It is this popular because it is a powerful protocol and it may be coupled with many other applications. However, users often run into a slew ofproblems, including incomplete conversion,overly degraded DNA, sub-optimal PCR amplifications, false positives, uninformative results, or altogether failed experiments. We pinpoint the reasons why these problems arise and carefully explain the critical steps toward accomplishing a successful experiment step-by-step. This protocol has worked successfully (>99.9% conversion) on as little as 100 ng of DNA derived from nearly 10-year-old DNA samples extracted from whole blood stored at -80°C and resulted in enough converted DNA for more than 50 PCRreactions. The aim of this article is to makelearning and usage of BGS easier, more efficient and standardized for all users.

ADDITION OF SODIUM BISULFITE TO BILIVERDIN

Summary:Sodium bisulfite could add to the central methine bridge of biliver- din in methanol,and give sodium bilirubin-10-sulfonate,however no bilirubin was formed.

Photocatalytic activation of sulfite by N-doped porous biochar/MnFe_(2)O_(4) interface-driven catalyst for efficient degradation of tetracycline

A novel photo-catalytic system composed of N-doped biochars(NBCs),MnFe_(2)O_(4) and sulfite activation under ultraviolet(NBCs/MnFe_(2)O_(4)/sulfite/UV)was constructed to realize the efficient eliminate of tetracycline(TC).As the carrier of MnFe_(2)O_(4),NBCs were synthesized from alfalfa,which has large specific surface area,graphite like structure and hierarchical porous structure.The adsorption isotherm indicated that NBCs/MnFe_(2)O_(4)-2:1 had the best adsorption performance for TC(347.56 mg g^(-1)).Through synergistic adsorption and photocatalysis,the removal rate of TC reached 84%,which was significantly higher than that of MnFe_(2)O_(4).Electrochemical impedance spectroscopy(EIS)and Photoluminescence(PL)characterization results showed that the introduction of NBCs improved the separation efficiency of photogenerated electron and hole pairs and enhanced the photocatalytic performance.Moreover,the adsorption,degradation mechanism and degradation path of TC by the catalyst were systematically analyzed by coupling HPLC–MS measurement with the theoretical calculation.Considering the advantages of excellent degradation performance,low cost,easy separation and environmental friendliness of NBCs/MnFe_(2)O_(4),this work was expected to provide a new path for the practical application of biochar.

Leaching kinetics of selenium from selenium-tellurium-rich materials in sodium sulfite solutions

The leaching kinetics of selenium from selenium-tellurium-rich materials in sodium sulfite solutions was studied. The morphologies of selenium-tellurium-rich materials are mainly spheroid and columnar bodies and the range of particle size of selenium-tellurium-rich materials is between 17.77μm and 56.58μm, which contain 41.73%selenium and 40.96%tellurium. The ranges of experimental elements are 126-315 g/L of sodium sulfite concentration, 100-400 r/min of agitation speed, 23-95 ℃ of reaction temperature, 7：1-14：1 of liquid-solid ratio and 17.77-56.58μm of average particle size. The results show that the leaching rate increases with increasing the sodium sulfite concentration, agitation speed, reaction temperature or liquid-solid ratio and the leaching rate decreases with increasing the particle size. The reaction temperature has the significant effects on the selenium leaching rate which increases from 21%to 67%with increasing temperature from 23 ℃ to 95 ℃. The experimental data agree quite well with the Avrami model for leaching, with model parameter of 0.235 and apparent activation energy of 20.847 kJ/mol.

Oxidation inhibition of sulfite in dual alkali flue gas desulfurization system

A laboratory-scale well-mixed thermostatic reactor with continuously blasting air was used to investigate the oxidation inhibition of sulfite in dual alkali flue gas desulfurization （FGD） system. The effects of operating parameters such as pH value and catalyst concentration on the oxidation were studied. Sodium thiosulfate was used in the system, and was found that it significantly inhabited the sulfite oxidation. In the absence of catalyst, sodium thiosulfate at 12.67 mmol/L had an inhibition efficiency of approximately 98%. While in the presence of catalyst, sodium thiosulfate at 26.72 mmol/L had an inhibition efficiency less than 85.0%. The oxidation reaction order of sulfite in the sodium thiosulfate was determined to be -1.90 and 4）.55 in the absence and presence of the catalyst, respectively. Apparent activation energy of oxidation inhibition was calculated to be 53.9 kJ/mol. Pilot tests showed that the consumption rate of thiosulfate agreed well with the laboratory-scale experimental results.

Determination of sulfite in water samples by flow injection analysis with fluorescence detection

A fast,sensitive,and reliable method for the determination of sulfite（SO3^2-） in fresh water and seawater samples was developed.The proposed method was based on the reaction of o-phthalaldehyde（OPA）-sulfite-NH_3 in alkaline solution,with flow injection analysis and fluorescence detection.The experimental parameters were investigated in pure water and seawater matrixes. The detection limits（S/N = 3） were 0.006μmol/L in pure water and 0.018μmol/L in seawater for SO3^2-.The method was successfully applied to analyze SO3^2- iin the samples of rain water and flue gas desulfurization seawater.

Catalytic oxidation of calcium sulfite in solution/aqueous slurry

Forced oxidation of calcium sulfite aqueous slurry is a key step for the calcium-based flue gas desulfurization(FGD) residue. Experiments were conducted in a semi-batch system and a continuous flow system on lab scales. The main reactor in semi-batch system is a 1000 ml volume flask. It has five necks for continuous feeding of gas and a batch of calcium sulfite solution/aqueous slurry. In continuous flow system, the main part is a jacketed Pyrex glass reactor in which gas and solution/aqueous slurry are fed continuously. Calcium sulfite oxidation is a series of complex free-radical reactions. According to experimental results and literature data, the reactions are influenced significantly by manganese as catalyst. At low concentration of manganese and calcium sulfite, the reaction rate is dependent on 1.5 order of sulfite concentration, 0.5 order of manganese concentration, and zero order of oxygen concentration in which the oxidation is controlled by chemical kinetics. With concentrations of calcium sulfite and manganese increasing, the reactions are independent gradually on the constituents in solution but are impacted by oxygen concentration. Manganese can accelerate the free-radical reactions, and then enhances the mass transfer of oxygen from gas to liquid. The critical concentration of calcium sulfite is 0.007 mol/L, manganese is 10 -4 mol/L, and oxygen is of 0.2—0.4 atm.

Effect of inhibitors on macroscopical oxidation kinetics of calcium sulfite

In the presence of inhibitors, the macroscopical oxidation kinetics of calcium sulfite, the main byproduct in wet limestone scrubbing, was studied for the first time by adding different inhibitors and varying pH, concentration of calcium sulfite, oxygen partial pressure, concentration of inhibitors and temperature. The mathematical model about the general oxidation reaction was established, which was controlled by three steps involving dissolution of calcium sulfite, mass transfer of oxygen and chemical reaction in the solution. It was concluded that the general reaction was controlled by mass transfer of oxygen under uncatalyzed conditions, while it was controlled by dissolution of calcium sulfite after adding three kinds of inhibitors. Thus, the theory was provided for investigating the mechanism and oxidation kinetics of sulfite. The beneficial references were also supplied for design of oxidation technics in the wet limestone scrubbing.

Electrochemical mechanism and flotation of chalcopyrite and galena in the presence of sodium silicate and sodium sulfite

The electrochemical mechanism involved in the selective separation of chalcopyrite from galena was investigated by flotation and electrochemical methods in the presence of sodium sulfite and sodium silicate,respectively,as a single depressant and their mixture as a combined depressant.Flotation tests revealed that the floatability of chalcopyrite was unaffected by depressants and its recovery remained constant(>80%)within the studied dosage range.Galena flotation was severely depressed with descending depressing order as follows:combined depressant﹥sodium silicate﹥sodium sulfite.Electrochemical analysis confirmed the high affinity of depressants on the galena surface,resulting in the formation of hydrophilic species,such as lead sulfite,lead sulfate,and lead orthosilicate.The oxidation of chalcopyrite surface and depressants did not exhibit any signals;conversely,the self-oxidation of chalcopyrite was depressed.The results of cyclic voltammograms well agreed with flotation results,demonstrating that chalcopyrite primarily reacted with the collector O-isopropyl-N-ethyl thionocarbamate and that galena mostly reacted with depressants.

Flow Injection Determination of Tramadol Based on Its Sensitizing Effect on the Chemiluminescent Reaction of Permanganate-Sulfite

In this paper, a novel chemiluminescence (CL) method for the determination of tramadol has been developed by combining the flow injection technique and its sensitizing effect on the weak CL reaction between sulfite and acidic KMnO4. A mechanism for the CL reaction has been proposed on the basis of fluorescent and CL spectra. Under the optimized conditions, the proposed method allows the measurement of tramadol hydrochloride over the range of 0.04 - 4 ?g/mLwith a correlation coefficient of 0.9995 (n = 8) and a detection limit of 0.01 ?g/mL (3σ), and the relative standard deviation for 2.0 ?g/mL tramadol (n = 11) is 2.1%. The utility of this method was demonstrated by determining tramadol hydrochloride in tablets and injections.

Physicochemical effects on sulfite transformation in a lipidrich Chlorella sp.strain

SO2 is very rapidly hydrated to sulfurous acid in water solution at pH value above 6.0, whereby sulfite is yielded from the disassociation of protons. We aimed to improve the sulfite transformation efficiency and provide a basis for the direct utilization of SO2 from flue gas by a microalgal suspension. Chlorella sp. XQ-20044 was cultured in a medium with 20 mmol/L sodium sulfite under different physicochemical conditions. Under light conditions, sulfite concentration in the algal suspension reduced linearly over time, and was completely converted into sulfate within 8 h. The highest sulfite transformation rate （3.25 mmol/ （L.h）） was obtained under the following conditions： 35℃, light intensity of 300 μmol/（m^2·s）, NaHCO3 concentration of 6 g/L, initial cell density （OD540） of 0.8 and pH of 9-10. There was a positive correlation between sulfite transformation rate and the growth of Chlorella, with the conditions favorable to algal growth giving better sulfite transformation. Although oxygen in the air plays a role in the transformation of SO3^2- to SO^2-, the transformation is mainly dependent on the metabolic activity of algal cells. Chlorella sp. XQ-20044 is capable of tolerating high sulfite concentration, and can utilize sulfite as the sole sulfur source for maintaining healthy growth. We found that sulfite 〈20 mmol/L had no obvious effect on the total lipid content and fatty acid profiles of the algae, Thus, the results suggest it is feasible to use flue gas for the mass production of feedstock for biodiesel using Chlorella sp. XQ-20044, without preliminary removal of SO2, assuming there is adequate control of the pH.

Effect of Addition of Sodium Dodecyl Sulfite on Physical Properties of Wheat Gluten Films

Films were made from the wheat glutens treated with 5%,10%,15%,20%,25% and 30%(wt% of gluten) of sodium dodecyl sulfite (SDS) in order to improve the properties of the films. Glycerol was used as a plasticizer.An addition of SDS in wheat glutens prior to forming films significantly increased the elongation at break(E) (P<0.05) and reduced notably the water vapor permeability(WVP) (P<0.05). In contrast,a decrease in the tensile strength(TS) of the films from gluten containing-SDS was found.Moreover,a significant decrease in P_(O_2) and P_(CO_2) of films from gluten treated with SDS was noticed. Although SDS-treated gluten film was slightly more yellow and darker than control one, it was not visually detrimental. It is indicated that the treatment with SDS prior to forming films greatly enhances the mechanical properties of wheat gluten films.The obivous improvement in water vapor permeability and extensibility of gluten films means that the use of SDS is a potential choice for improving properties of gluten films. The edible film was used to preserve tomatoes. The experimental results show that the shelf life of tomatoes coated with the edible film is extended, and the nutritional quality is kept well.

Risk Analysis of Sulfites Used as Food Additives in China

This study was to analyze the risk of sulfites in food consumed by the Chinese people and assess the health protection capability of maximum-permitted level （MPL） of sulfites in GB 2760-2011. Sulfites as food additives are overused or abused in many food categories. When the MPL in GB 2760-2011 was used as sulfites content in food, the intake of sulfites in most surveyed populations was lower than the acceptable daily intake （ADI）. Excess intake of sulfites was found in all the surveyed groups when a high percentile of sulfites in food was intaken. Moreover, children aged 1-6 years are at a high risk to intake excess sulfites. The primary cause for the excess intake of sulfites in Chinese people is the overuse and abuse of sulfites by the food industry. The current MPL of sulfites in GB 2760-2011 protects the health of most populations.

Enhancement of Enzymatic Saccharification of Wheat Straw Residue by Ammonium Sulfite Pretreatment

Efficient utilization of wheat straw residue(WSR) from pulp mills is an important priority for the sustainable development of the pulp and paper industry. In this study, the effects of ammonium sulfite(AS) pretreatment with different AS charges(wt%) and pretreatment temperatures on the chemical composition and enzymatic hydrolysis of WSR were studied. The results revealed that more lignin was removed with the increase of pretreatment temperature and AS charge. The degradation of hemicellulose became severe at high pretreatment temperature, while cellulose remained stable during the pretreatment process. The enzymatic hydrolysis efficiency of pretreated WSR was increased and then decreased with the increase of the AS charge and pretreatment temperature. The AS charge exerts a stronger effect on enzymatic hydrolysis efficiency than the pretreatment temperature. Glucan and xylan conversion ratios up to 88.9% and 44.9%, respectively, were obtained. The highest total sugar conversion ratio was 67.0% when WSR pretreated with 16% AS at 165℃ was hydrolyzed with a cellulase loading of 40 FPU per gram of glucan.

Anodic dissolution of gold in alkaline solutions containing thiourea, thiosulfate and sulfiteions

Gold dissolves electrochemically in alkaline solutions containing ligands to form complex ions with gold ion. Therefore, selective leaching of noble metals is expected without dissolution of base metals such as steels, aluminum alloys in scrap treatment. Gold electrodes were investigated using linear sweep voltammetry, EQCM method and potentiostatic electrolysis in alkaline solutions containing thiourea, Na 2SO 3 and Na 2S 2O 3. The solution composition, electrode potential affect gold dissolution rate and current efficiency. The gold dissolved from anode electrode forms complex ions, suspension particles as compound precipitates and deposits on cathode electrode as a metal. Anodic efficiency for gold dissolution is between 10% and 22%. This is caused by the oxidation decomposition of sulfite ions and thiourea. The stability of the alkaline solution containing these elements was also estimated by capillary electrophoresis technique.

Chloro-propylene Sulfite as Electrolyte Additive for Li/S Batteries

Chloro-propylene sulfite （CIPS） was employed as electrolyte additive of Li/S batteries for the first time. Linear potential sweep test showed that the CIPS keeps high electrochemical stability even under the voltage of 5.0V. Being used as electrolyte additive in Li/S batteries, CIPS displayed an excellent property for self-discharge prohibition. With CIPS additive the Li/S cells initial discharge capacity was 856.2 mAh·g^-1 and 830.8 mAh·g^-1 at the current density of 15 mA.g and 30 mA·g^-1 , after 30 cycles the discharge capacities were contained at as high as 753.8 mAh.g and 715.6 mAh·g^-1. By means of infrared spectra, TG/DTA experiment and element conten analysis the speculated reason of CIPS＇s novel function as additive was proposed.