scholarly journals TOTAL CHLORINE-FREE BLEACHING OF SULFATE HARDWOOD PULP WITH HYDROGEN PEROXIDE

2019 ◽  
pp. 287-294
Author(s):  
Фирдавес (Firdaves) Харисовна (Harisovna) Хакимова (Hakimova) ◽  
Константин (Konstantin) Андреевич (Andreevich) Синяев (Sinyaev)
Keyword(s):  
Hydrogen Peroxide ◽  
Mechanical Strength ◽  
Small Proportion ◽  
Pulp Fibers ◽  
Pulp Bleaching ◽  
Sulfate Pulp ◽  
Environmentally Safe ◽  
Hardwood Pulp ◽  
High Degree ◽  
Pulp Production

The work is devoted to the study of the possibility and feasibility of environmentally safe bleaching of sulfate hardwood pulp by TCF-technology without the use of traditional oxygen and ozone as a delignifying reagent. The TCF-technology of sulphate hardwood pulp bleaching (scheme Pa-EP-Pd-Aac-P-A) was developed with only one oxidizing reagent – hydrogen peroxide. It is proposed to carry out of pulp delignification with hydrogen peroxide in an acid medium conditions, additional delignification and bleaching – with hydrogen peroxide in an alkaline medium conditions. Soft oxidizing effect of hydrogen peroxide used at all stages of bleaching provides selectivity of the process along with ecological compatibility of the scheme. The mechanical strength of pulp varies during bleaching in accordance with the change of the degree of delignification and is very moderate, and the total loss of pulp fibers is only 6.1%. Production of hardwood sulfate pulp, as well as sulfite, is associated with difficulties caused by a "harmful" resin at a small proportion of extractives. The proposed scheme of bleaching provides a high degree of resin removal and contributes to the depitching, i.e. decision of very important problems in sulphate hardwood pulp production.

scholarly journals Minimizing the Chlorine Content in Bleached Sulfate Pulp for Sanitary Tissue products and Food Packaging

2021 ◽  
pp. 186-195
Author(s):  
Ekaterina D. Sofronova ◽  
◽  
Vadim А. Lipin ◽  
Vladimir К. Dubovy ◽  
Tatyana А. Sustavova
Keyword(s):  
Food Packaging ◽  
Raw Materials ◽  
Paper Industry ◽  
Chlorine Content ◽  
Pulp Bleaching ◽  
Allowable Limit ◽  
Elemental Chlorine ◽  
Sulfate Pulp ◽  
Pulp Production

The increasing consumption of pulp for chemical processing, including production of sanitary tissue products and other medical products, food packaging, as well as fillers for food products leads to new requirements for the quality of raw materials. The task of improving the characteristics of pulp has become particularly acute in connection with the COVID-19 epidemic: the demand for disposable nonwoven materials in direct contact with the human skin has increased several times over. The elemental chlorine free (ECF) sulfate pulp bleaching process, which uses chlorine dioxide as a bleaching agent, dominates bleached pulp production worldwide. The chlorine-containing compounds formed as a result of bleaching pollute not only waste water, but also the product itself. In the near future, it is expected that paper products made with chlorine-based bleaches may be banned for the production of sanitary tissue products and food packaging. If the products of the pulp and paper industry do not meet international consumer requirements, the pulp market for these purposes may face undesirable results. The most promising direction of modernization the existing bleaching schemes, both in terms of the process consumption parameters and the quality of the produced pulp, is the use of oxygen-alkaline bleaching in the first stage. Determination of total and organically bound chlorine content in pulp materials in accordance with ISO 11480:2017 on the advanced plant has shown, that the introduction of bleaching schemes using oxygen-alkaline agents will ensure the recommended content of chlorine compounds while maintaining the necessary characteristics of pulp for the manufacture of medical and sanitary tissue products, food packaging. However, high quality of finished products that meet consumers’ requirements is possible only if the chlorine content is controlled at all stages of pulp production, since the quantitative indicators of this substance content remain close to the upper allowable limit. For citation: sofronova e.D., Lipin v.A., Dubovy v.K., Sustavova t.A. Minimizing the Chlorine Content in bleached sulfate pulp for sanitary tissue products and food packaging. Lesnoy Zhurnal [Russian Forestry Journal], 2021, no. 3, pp. 186–195. DOI: 10.37482/0536-1036-2021-3-186-195

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%.

scholarly journals A Mn(iii) polyoxotungstate in the oxidation of organosulfur compounds by H2O2 at room temperature: an environmentally safe catalytic approach

2016 ◽  
Vol 6 (9) ◽  
pp. 3271-3278 ◽  
Author(s):  
Tiago A. G. Duarte ◽  
Sónia M. G. Pires ◽  
Isabel C. M. S. Santos ◽  
Mário M. Q. Simões ◽  
M. Graça P. M. S. Neves ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Room Temperature ◽  
Organosulfur Compounds ◽  
Keggin Type ◽  
Environmentally Safe

A manganese monosubstituted Keggin-type polyoxometalate was used as a catalyst in the oxidation of recalcitrant organosulfur compounds by hydrogen peroxide at room temperature.

Catalase released from beneficial and plant-pathogenic pseudomonads by water and chloroform treatments

1994 ◽  
Vol 40 (8) ◽  
pp. 630-636
Author(s):  
J. I. Pounder ◽  
A. J. Anderson
Keyword(s):  
Hydrogen Peroxide ◽  
Superoxide Dismutase ◽  
Water Treatment ◽  
Pseudomonas Syringae ◽  
Small Proportion ◽  
Plant Colonization ◽  
Periplasmic Proteins ◽  
Specific Activities ◽  
Leaf Pathogen ◽  
Glucose 6 Phosphate Dehydrogenase

Survival of pseudomonads during plant colonization may involve bacterial catalases to degrade the hydrogen peroxide produced by the plant. The specific activities of catalases in lysates from two saprophytic isolates of Pseudomonas putida and Pseudomonas fluorescens and three races of Pseudomonas syringae pv. glycinea were similar. To explore the location of the bacterial catalases, cells of the pathogenic and saprophytic pseudomonads were treated with chloroform, which is reported to release periplasmic proteins. Although catalase was released by chloroform treatment, the cytoplasmic enzymes isocitrate dehydrogenase, superoxide dismutase, and glucose-6-phosphate dehydrogenase were also detected. These proteins may have come from lysis of a small proportion of the cells rather than the periplasm. Water treatment of cells also released amounts of protein similar to those derived from chloroform treatment. Similar responses were found from both pathogenic and saprophytic strains. The release of catalase and proteins from the leaf pathogen P. syringae pv. glycinea race 0 and the root-associated saprophyte P. putida decreased as the cultures aged. With P. putida and P. syringae pv. glycinea race 0, the single isozyme of catalase released by water and chloroform treatment also was detected in lysates. Additional catalase isozymes were present in lysates as the cultures aged.Key words: periplasmic proteins, survival.

Treatability of kraft pulp bleaching wastewater by biochemical and photocatalytic oxidation

1999 ◽  
Vol 40 (1) ◽  
pp. 281-288 ◽  
Author(s):  
Işıl Akmehmet Balcıoǧlu ◽  
Ferhan Çeçen
Keyword(s):  
Biological Treatment ◽  
Kraft Pulp ◽  
Photocatalytic Oxidation ◽  
Treated Wastewater ◽  
Oxidation Reactions ◽  
Pulp Bleaching ◽  
Kraft Pulp Bleaching ◽  
Activated Sludge Reactor ◽  
Sulfate Pulp ◽  
Biological Treatability

In this study the biological treatability and TiO2 photocatalyzed oxidation characteristics of sulfate pulp bleaching effluents were investigated. The original wastes had a low biodegradability as determined by BOD5/COD ratios. Biological treatment was conducted in a batch activated sludge reactor. The non-biodegradable fraction amounted to 60% of the initial COD and compounds specific to these wastes were not removed during biotreatment. In order to enhance the biodegradability of these wastes, mixed raw effluent, C/E-H stage effluent, D/E-D stage effluent and biologically pretreated wastes were subjected to TiO2 photocatalyzed oxidation. Photocatalytic oxidation led to an increase in the BOD5/COD ratio of D/E-H stage raw and biologically treated wastewater, while chloride formation was observed in both cases in a five-hour reaction period in the presence of 1g 1−1 TiO2 and 15×10−3 M H2O2 at pH=6.5. The specific absorption values (A272nm/CODs, A254nm/CODs, A346nm/CODs, A436nm/CODs) exhibited parallel decreases during photocatalytic oxidation which indicate that oxidation reactions were nonspecific with respect to the organics present in these wastes. As a conclusion it can be suggested that biological treatment should be placed before the photocatalytic oxidation method. Even in this scheme, the application of photocatalytic oxidation could only then be favored when the COD and chloride concentrations in the wastewater were below certain values or when wastewater was diluted.

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.

Evaluation of Horseradish Peroxidase for the Treatment of Estrogenic Alkylphenols

2005 ◽  
Vol 40 (2) ◽  
pp. 145-154 ◽  
Author(s):  
Monika Wagner ◽  
James A. Nicell
Keyword(s):  
Hydrogen Peroxide ◽  
Reaction Time ◽  
Horseradish Peroxidase ◽  
Estrogenic Activity ◽  
Complete Disappearance ◽  
Reaction Products ◽  
Compound A ◽  
New Approach ◽  
Microtox Toxicity ◽  
High Degree

Abstract The xenoestrogen alkylphenols 4-nonylphenol (3.4 mg/L) and octylphenol (6.0 mg/L) were oxidized by hydrogen peroxide using horseradish peroxidase (HRP) as a biocatalyst. Substrate transformation required about one mole of peroxide per mole of phenolic compound. A high degree of conversion of alkylphenol was achieved within a 3-h reaction time. In the case of 4-nonylphenol, HRP treatment led to complete disappearance of Microtox toxicity. Results of the yeast estrogen screen (YES) assay demonstrated that the reaction products of HRP-catalyzed 4-nonylphenol conversion lacked estrogenic activity. A new approach to the YES assay has been suggested based on observations made during this study.

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