Use of an Improved Chemiluminescence Assay for Non-Intrusive Measurement of Hydroxyl Radicals in a Biomimetic Pulp Bleaching Model System

Holzforschung ◽  
1999 ◽  
Vol 53 (2) ◽  
pp. 181-187 ◽  
Author(s):  
C. C. Walker ◽  
R. J. Dinus ◽  
T. J. McDonough ◽  
K.-E. L. Eriksson
Keyword(s):  
Hydrogen Peroxide ◽  
Aqueous Solutions ◽  
Hydroxyl Radicals ◽  
Model System ◽  
Pulp Bleaching ◽  
Assay Sensitivity ◽  
Chemiluminescence Assay ◽  
Naturally Occurring ◽  
Excellent Tool

Summary A chemiluminescence assay was used to measure the production of hydroxyl radicals (·OH) in aqueous solutions of hydrogen peroxide and iron-containing catalysts. Preliminary experiments evaluating assay sensitivity revealed that one of the required reagents, phthalhydrazide (PtH), interfered with the studied reactions. In addition, undesirable degradation of the chemiluminescent form of PtH was observed. By removing PtH from reaction solutions and modifying the published procedures, a successful non-intrusive method for measurement of ·OH was obtained. The modified assay was used to compare the rate of ·OH generation in solutions of H2O2, either FeSO4 or Fe-EDTA and a substrate, lignosulfonate. This “biomimetic” pulp bleaching system is meant to simulate naturally occurring biological reactions utilized for degradation of lignins by wood-degrading fungi. Results from these experiments show that FeSO4 produced more ·OH than Fe-EDTA. The improved non-intrusive chemiluminescence assay has proven to be an excellent tool for investigating the role of the ·OH in biomimetic pulp bleaching and potentially other systems.

Pulp Mill Effluent Treatment by Fenton-Type Reactions Catalyzed by Iron Complexes

1999 ◽  
Vol 40 (11-12) ◽  
pp. 351-355 ◽  
Author(s):  
Jaime Rodríguez ◽  
David Contreras ◽  
Carolina Parra ◽  
Juanita Freer ◽  
Jaime Baeza ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Aqueous Solutions ◽  
Fenton Reaction ◽  
Pulp Mill ◽  
Effluent Treatment ◽  
Pulp Mill Effluent ◽  
Large Decrease ◽  
Dihydroxybenzoic Acid ◽  
Pulp Bleaching ◽  
Efficient Option

Fenton reaction, which involves hydrogen peroxide and ferrous ion, has been proposed as an efficient option for effluent treatment. In this work, the treatment of a pulp bleaching effluent using Fenton-type reactions assisted by either, 2,3-dihydroxybenzoic acid (2,3-DHBA), 3,4-dihydroxybenzoic acid (3,4-DHBA) and 1,2-dihydroxybenzene (CAT), were studied. The treatment was evaluated by the removal of adsorbable organochloride compounds (AOX) and toxicity. Furthermore, the degradation of 2-chlorophenol and 4-chlorophenol in aqueous solutions were carried out, separately. Increase in oxidative activities of Fenton-type reactions mediated by the dihydroxybenzenes (DHBs) were found. These activities enhancement were related with a higher production of activated species by Fe/DHBs/H2O2, as indicted by chemiluminesce. The large decrease in AOX values and toxicity of the treated bleaching effluent by DHBs at pH 4.0 and 7.0 showed that 2,3-DHBA enhanced the activity of the Fenton reaction. The use of 3,4-DHBA and CAT resulted in loss of efficiencies of Fenton reaction to effluent treatment but not to pure chlorophenol solutions. At pH 7.0 lower efficiencies than those at pH 4.0 were achieved.

Role of Hydroxyl Radicals inEscherzchza ColzKilling Induced by Hydrogen Peroxide

1989 ◽  
Vol 6 (1) ◽  
pp. 47-55 ◽  
Author(s):  
Giorgio Brandi ◽  
Flaminio Cattabeni ◽  
Amedeo Albano ◽  
Orazio Cantoni
Keyword(s):  
Hydrogen Peroxide ◽  
Hydroxyl Radicals

Selectivity and Efficiency of Biomimetic Catalysts in a Model System for Pulp Bleaching

Holzforschung ◽  
2001 ◽  
Vol 55 (4) ◽  
pp. 391-396 ◽  
Author(s):  
C. C. Walker ◽  
T. J. McDonough ◽  
R. J. Dinus ◽  
K.-E. L. Eriksson
Keyword(s):  
Kinetic Model ◽  
Hydroxyl Radicals ◽  
Chain Scission ◽  
Model System ◽  
Hydroxyethyl Cellulose ◽  
Pulp Bleaching ◽  
Sodium Lignosulfonate ◽  
Biomimetic Catalysts ◽  
Biomimetic Systems ◽  
Simple Kinetic Model

SummaryThree biomimetic systems were evaluated for their selectivity in a model system for pulp. FeSO4, Fe-EDTA and hemoglobin, in the presence of H2O2, constituted the biomimetic systems. Sodium lignosulfonate and hydroxyethyl cellulose (HEC) were used as a model system to represent lignin and carbohydrate fractions in pulp. A simple kinetic model was used to determine kinetic parameters for depolymerization of each substrate. Point selectivities at two different H2O2concentrations were evaluated on the basis of the resulting expressions. Hemoglobin demonstrated superior selectivity for lignosulfonate degradation at a high H2O2level. The production of hydroxyl radicals from each of the biomimetic systems was measured using a chemiluminescence assay. For the FeSO4and Fe-EDTA systems, depolymerization was related to the amount of radicals generated. The fate of reacted H2O2was evaluated using a specially designed reactor to measure H2O2consumed by reaction and that decomposed. To achieve a given number of chain scission in lignosulfonate, the hemoglobin system consumed the least amount of H2O2.

Role of an Inorganic Phosphate in the Photogeneration of Hydrogen Peroxide in Aqueous Solutions of Adenine Derivatives at 77 K

2021 ◽  
Vol 95 (8) ◽  
pp. 1591-1600
Author(s):  
T. A. Lozinova ◽  
A. V. Lobanov ◽  
E. N. Degtyarev ◽  
O. N. Brzhevskaya ◽  
A. V. Lander
Keyword(s):  
Hydrogen Peroxide ◽  
Aqueous Solutions ◽  
Inorganic Phosphate ◽  
Adenine Derivatives

X-ray- and heat-induced generation of hydrogen peroxide and hydroxyl radicals in aqueous solutions of L-amino acids

BIOPHYSICS ◽  
2008 ◽  
Vol 53 (1) ◽  
pp. 1-7 ◽  
Author(s):  
I. N. Shtarkman ◽  
S. V. Gudkov ◽  
A. V. Chernikov ◽  
V. I. Bruskov
Keyword(s):  
Amino Acids ◽  
Hydrogen Peroxide ◽  
Aqueous Solutions ◽  
Hydroxyl Radicals ◽  
X Ray
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