OXIDATION OF D-GALACTURONIC ACID WITH SOME DELIGNIFYING AND BLEACHING AGENTS

1959 ◽  
Vol 37 (11) ◽  
pp. 1820-1828 ◽  
Author(s):  
R. H. Zienius ◽  
C. B. Purves
Keyword(s):  
Hydrogen Peroxide ◽  
Chlorine Dioxide ◽  
Galacturonic Acid ◽  
Uronic Acid ◽  
Silver Salt ◽  
Sodium Chlorite ◽  
Mucic Acid ◽  
Acid Methyl ◽  
Tartronic Acid ◽  
Approximate Order

D-Galacturonic acid was oxidized with decreasing ease, and in the approximate order shown, by excess of the following agents: sodium chlorite near pH 2.8 and 75°; sodium hypochlorite at pH 10–11 and 25°; chlorine dioxide, pH 1.3 or 5 at 75°; chlorine near 0° and pH 5 (slight); and hydrogen peroxide at pH 10–11 and 25° (negligible). Some uronic acid was always recovered unchanged, even from conditions that would have oxidized glucose quantitatively to gluconic acid. The only other products were mucic acid, together with DL-tartaric acid and tartronic acid presumably derived therefrom. Chlorine dioxide, however, never produced tartronic acid. Methyl-α-D-galacturonoside methyl ester yielded some galacturonic acid when exposed to alkaline hypochlorite or peroxide, and this cleavage of the glycosidic group was tentatively attributed to the oxidants rather than to the alkalinity of the systems.Anhydrous bromine degraded the silver salt of methyl-α-D-galacturonoside in poor yield to a syrup which was probably L-arabotrihydroxyglutaric dialdehyde.

STUDIES IN THE POLYOXYPHENOL SERIES: VIII. THE OXIDATION OF SUBSTANCES RELATED TO VANILLIN WITH SODIUM CHLORITE AND CHLORINE DIOXIDE

1955 ◽  
Vol 33 (1) ◽  
pp. 82-96 ◽  
Author(s):  
C. D. Logan ◽  
R. M. Husband ◽  
C. B. Purves
Keyword(s):  
Hydrogen Peroxide ◽  
Chlorine Dioxide ◽  
Sodium Chlorite ◽  
Veratric Acid ◽  
Simultaneous Formation ◽  
Aqueous Sodium ◽  
Sharp Distinction ◽  
Slow Reaction ◽  
Ph Values ◽  
Chlorous Acid

The research confirmed the fact that chlorine dioxide and sodium chlorite were not equivalent in their oxidizing properties. At 22 °C. or less, the oxidation of pyrogallol by aqueous sodium chlorite at pH 6 was very slow, but became very rapid on the acid side of pH 3.5. The amorphous, colored products probably did not include purpurogallin. Under similar circumstances p-hydroxybenzaldehyde was unaffected at pH 6; 22% was oxidized to p-benzoquinone (Dakin's reaction) at pH 5, and this amount increased to 39% at pH 1. The yield of benzoquinone was about 24% regardless of pH within the above range when aqueous chlorine dioxide was the oxidant. Sodium chlorite at pH 0.9 produced a 91% yield of methoxy-p-quinone from methoxy-p-hydroquinone; at pH 4 this product was mixed with 56% of 4,4′-dimethoxydiquinone, but near pH 6 a slower oxidation did not proceed beyond 4,4′-dimethoxyquinhydrone. Aqueous chlorine dioxide yielded at least 92% of monomeric methoxyquinone at all pH values between 1 and 6, probably in accord with the equation,[Formula: see text] The simultaneous formation of hydrogen peroxide was suspected, but not proved. In sharp distinction to the behavior of free phenols, veratraldehyde was not oxidized by aqueous chlorine dioxide between pH 6 and pH 3, but at pH 1 a slow reaction yielded up to 15% of veratric acid. Sodium chlorite produced about 92% of the same acid at pH 1 and pH 4, but its action was negligible at pH 5. Since by-product chlorine dioxide was ineffective at pH 4, it was possible to confirm the validity of the Jeanes–Isbell equation for the reduction of chlorous acid:[Formula: see text]The oxidation of acetylated vanillin was complicated by the occurrence of deacetylation. Red, chlorinated oils with quinoidal properties were also formed in most of the above oxidations.

INDUCTION AND REPRESSION OF ENDOPOLYGALACTURONASE SYNTHESIS BY PYRENOCHAETA TERRESTRIS

1966 ◽  
Vol 12 (3) ◽  
pp. 443-453 ◽  
Author(s):  
N. T. Keen ◽  
J. C. Horton
Keyword(s):  
Galacturonic Acid ◽  
Liquid Culture ◽  
Mucic Acid ◽  
Tartronic Acid ◽  
Pyrenochaeta Terrestris ◽  
Fungus Growth

Endopolygalacturonase (endo-PG) synthesis was inducible in standing and replacement liquid culture by Pyrenochaeta terrestris. Inducers were galacturonic acid, its polymers (pectin and polypectate), and structural relatives (mucic acid, tartronic acid, and dulcitol). On pectin, fungus growth and endo-PG synthesis were proportional to initial pectin concentration.Synthesis of endo-PG on pectin was stimulated by hexose supplements at 0.005 M and repressed by supplements at 0.05 M and above. Thus, repression of induced endo-PG synthesis was not dominant at low supplement concentrations as was found for induced cellulase synthesis by the same organism. This suggests that the production of endo-PG by the parasite during pathogenesis is less repressed by host sugars than is cellulase synthesis.

Bleaching optimization at WestRock mill in Covington, Virginia

TAPPI Journal ◽  
2016 ◽  
Vol 15 (9) ◽  
pp. 581-586 ◽  
Author(s):  
RICARDO B. SANTOS ◽  
PETER W. HART ◽  
DOUGLAS C. PRYKE ◽  
JOHN VANDERHEIDE
Keyword(s):  
Hydrogen Peroxide ◽  
Sodium Hydroxide ◽  
Chlorine Dioxide ◽  
Capital Expenditures ◽  
Equipment Repair ◽  
Optimization Program ◽  
Hardwood Pulp ◽  
Improved Performance

The WestRock mill in Covington, VA, USA, initiated a long term diagnostic and optimization program for all three of its bleaching lines. Benchmarking studies were used to help identify optimization opportunities. Capital expenditures for mixing improvement, filtrate changes, equipment repair, other equipment changes, and species changes were outside the scope of this work. This focus of this paper is the B line, producing southern hardwood pulp in a D(EP)DD sequence at 88% GE brightness. The benchmarking study and optimization work identified the following opportunities for improved performance: nonoptimal addition of caustic and hydrogen peroxide to the (EP) stage, carryover of D0 filtrate to the (EP) stage, and carryover of (EP) filtrate to the D1 stage. As a result of actions the mill undertook to address these opportunities, D0 kappa factor decreased about 5%, sodium hydroxide consumption in the (EP) stage decreased about 35%, chlorine dioxide consumption in the D1 stage decreased about 25%, and overall bleaching cost decreased about 15%.

Binding of calcium, lead, and copper(II) cations to galactaric and 2,5-furandicarboxylic acids and to D-galacturonic acid and its derivatives

1986 ◽  
Vol 51 (5) ◽  
pp. 1150-1159 ◽  
Author(s):  
Rudolf Kohn ◽  
Ján Hirsch
Keyword(s):  
Galacturonic Acid ◽  
Uronic Acid ◽  
Indicator Method ◽  
Cu Complex ◽  
Carboxylate Groups ◽  
Counter Ions ◽  
Galactaric Acid ◽  
Furandicarboxylic Acid ◽  
The Difference ◽  
Calcium Lead

The binding of Ca2+, Pb2+, and Cu2+ ions to galactaric and 2,5-furandicarboxylic acids and of Pb2+ and Cu2+ ions to D-galacturonic acid, its α-methylglycoside, and (methyl-4-deoxy-α-D-galactopyranosid)uronic acid was evaluated in terms of the activity coefficients of the counter-ions and the degrees of their association with the carboxylate groups of the acids. The activity of Ca2+ ions was determined by the metallochromic indicator method with tetramethylmurexide, that of Pb2+ and Cu2+ ions, with ion specific electrodes. Galactaric acid bids 89.5% Ca2+ ions, practically all (99.9%) Pb2+ ions and nearly all (98.6% Cu2+ ions, mostly with the formation of insoluble salts. As little as 7.6% Ca2+, 34.0% Pb2+, and 23.9% Cu2+ were bound to 2,5-furandicarboxylic acid in the form of soluble complexes, and slightly more, 4.1% Ca2+, 43.9% Pb2+, and 38.0% Cu2+, to D-galacturonic acid. The difference in the degrees of binding to galactaric acid and 2,5-furandicarboxylic acid is due to the different flexibility of their molecular skeletons. The activities of Pb2+ and Cu2+ ions in solutions of salts of D-galacturonic acid and its derivatives indicate that the OH group at C(4) of D-galacturonic acid takes part in the complexation. For the Pb2+ complex, the OH group at C(1) of the unsubstituted acid in the β-anomeric form also seems to participate in the complexation; this is not the case with the similar Cu complex.

scholarly journals Hydrogen peroxide and chlorine dioxide against parasite Ichthyophthirius multifiliis (Protozoa, Ciliophora) in jundiá fingerlings

2017 ◽  
Vol 47 (12) ◽  
Author(s):  
Natalia da Costa Marchiori ◽  
Fabiano Muller Silva ◽  
Maurício Laterça Martins ◽  
Hilton Amaral Junior ◽  
Bruno Corrêa da Silva
Keyword(s):  
Hydrogen Peroxide ◽  
Chlorine Dioxide ◽  
Fish Farming ◽  
Control Group ◽  
Chemical Agent ◽  
Ichthyophthirius Multifiliis ◽  
Larval Phase ◽  
Group Data ◽  
Active Chemical ◽  
Continuous Bath

ABSTRACT: Ichthyophthiriasis is a worldwide fish disease with great financial impact on freshwater fish farming due to its associated high mortality rates. Current study assesses the parasiticidal capacity of hydrogen peroxide (H2O2) and chlorine dioxide (ClO2) against the causative agent, Ichthyophthirius multifiliis, in jundiá. Median lethal concentration (LC50, 96h) of each chemical agent was established, as well as the minimum inhibitory concentration of hydrogen peroxide for the parasite´s infectious larval phase (theront). Products were tested asynchronously in parasitized fingerlings for short and long baths at the following concentrations and exposure times: 1. Hydrogen peroxide: (T1) continuous bath - 30ppm and (T2) 50ppm; (T3) short bath - 150ppm, during 1h and (T4) 250ppm during 1h; control group (without any chemical agent). 2. Chlorine dioxide: (T1) continuous bath - 4ppm and (T2) 20ppm; (T3) short bath - 200ppm, during 1min; (T4) short bath - 400ppm, during 1min and control group. Data analysis demonstrated a concentration of 82.54ppm of the commercial product (or 24.76ppm of the active chemical agent) as LC50, 96h of H2O2 and 38.4ppm product (or 2.68ppm of the active chemical agent) for ClO2. Hydrogen peroxide concentration causing 100% mortality rate of theronts in 1h was 25ppm (product, or 7.5ppm of the active chemical agent). At the end of the fourth day of curative experiment, 98% of the animals died by ichthyophthiriasis. No treatment was effective against the parasite.

scholarly journals CARBOXYMETHYL CELLULOSE SYNTHESIS FROM TREATED OIL PALM EMPTY FRUIT BUNCH USING IONIC LIQUID AND HYDROGEN PEROXIDE

2021 ◽  
Vol 11 (4) ◽  
pp. 80-88
Author(s):  
Muzakkir Mohammad Zainol ◽  
Nurul Suhada Ab Rasid ◽  
Mohd Asmadi ◽  
Nor Aishah Saidina Amin
Keyword(s):  
Hydrogen Peroxide ◽  
Ionic Liquid ◽  
Carboxymethyl Cellulose ◽  
Proton Nuclear Magnetic Resonance ◽  
Sodium Chlorite ◽  
Cellulose Synthesis ◽  
Empty Fruit Bunch ◽  
Acid Pretreatment ◽  
Ionic Liquid Pretreatment ◽  
Magnetic Resonance Scanning

The synthesis of carboxymethyl cellulose (CMC) generally uses isolated crude cellulose with alkaline or acid pretreatment followed by bleaching with sodium chlorite. In this study, the simple [BMIM][Cl] ionic liquid was used as a solvent in the pretreatment process before conduct the bleaching process with hydrogen peroxide (H2O2) to isolate cellulose from empty fruit bunch (EFB) for further synthesis of CMC. The isolated crude EFB cellulose obtained was converted to CMC by adding 30 wt.% NaOH and various concentrations of sodium monochloroacetic acid (SMCA) at 55 °C for 3 h. The effects of SMCA concentration on the degree of substitution (DS) and CMC yield were investigated. The physicochemical properties of the CMC products were characterized using proton nuclear magnetic resonance, scanning electron microscope-energy dispersive spectrometry, X-ray diffraction, and thermogravimetric analysis. Based on the results, CMC was demonstrated to be synthesized using ionic liquid pretreatment with H2O2 bleaching. Carboxymethyl cellulose synthesized in this study showed a high DS of 0.82. The CMC synthesized from EFB cellulose through ionic liquid pretreatment presented good chemical and physical properties as that reported in other studies.

Initiating ECF bleaching sequences of eucalyptus kraft pulps with Z/D and Z/E stages

Holzforschung ◽  
2010 ◽  
Vol 64 (1) ◽  
Author(s):  
Juan C. García ◽  
Francisco López ◽  
Antonio Pérez ◽  
M. Angels Pèlach ◽  
Pere Mutjé ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Chlorine Dioxide ◽  
Ecological Impact ◽  
Substantial Reduction ◽  
Reference Sequence ◽  
Kraft Pulps ◽  
Eucalyptus Kraft Pulp ◽  
The Impact ◽  
Ecf Bleaching ◽  
Ozone Bleaching

Abstract Ozone bleaching is a common practice in pulping, and also of eucalyptus, where it is usually applied in combination with bleaching sequences based on oxygen, hydrogen peroxide, or chlorine dioxide. Ozone has been proven to be a highly efficient and competitive bleaching chemical in terms of delignification efficiency, low costs, and reducing ecological impact. The objective of the present work was to evaluate technology with ozone/alkaline extraction (Z/E) and ozone/chlorine dioxide (Z/D) for bleaching of eucalyptus kraft pulp. Primarily, the impact of these bleaching steps on refinability and quality of pulp should be investigated. As reference, the sequence D*(EP)D (hot chlorine dioxide, extraction in presence of hydrogen peroxide, chlorine dioxide) was selected, which is considered as the state-of-the-art bleaching in elemental chlorine free (ECF) bleaching technology. Various bleaching sequences with ozone in their first step (Z/D(EP)DP, Z/D(EP)DD, Z/EDP, Z/EDD and A*Z/EDP) were found to provide kraft pulps of similar brightness and in similar yield as the reference sequence D*(EP)D. The kappa number, viscosity, and the contents of glucose and xylose, and hexenuronic acid of the pulps were also similar. In addition, the Z sequences resulted in a substantial reduction of the total chlorine dioxide consumption (more than 30.3% in all cases). The A*Z/EDP sequence, which proved to be the most efficient, yielded 87.5% ClO2 reduction. The studied bleaching sequences also resulted in substantially improved brightness reversal with regard to the reference sequence. The sequence A*Z/EDP was also the most efficient as regards the removal or organochlorines (OX) from the pulp and their reduction in the effluents (AOX). Ozone bleaching sequences improved paper strength, especially with the A*Z/EDP sequence.

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