Kinetics of Adsorbable Organic Halides (AOX) Reduction in Laccase-Aided Chlorine Dioxide Bleaching of Bagasse Pulp

The feasibility of using ozonation and adsorption for the post-treatment of biologically treated effluents of the pulp and paper industry has been studied. Equilibrium conditions, as well as the kinetics of both processes, have been determined. The COD, AOX (adsorbable organic halides) content and color were chosen as the main process parameters. General design of an ozone reactor and adsorption unit, as well as estimates of capital and operating costs for both processes, have also been presented. Some remarkable advantages of ozonation in comparison to PAC-adsorption have been emphasized: at the same purification cost ($/m3) ozonation can guarantee 7-8 times higher efficiency than adsorption. Destroying color bodies and toxic organochlorine compounds in the effluents from the pulp and paper industry with ozone has become very promising.

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Reducing the formation of adsorbable organic halides using an ammonium thiosulfate chlorine dioxide bleaching process

BioResources ◽

10.15376/biores.15.4.8677-8688 ◽

2020 ◽

Vol 15 (4) ◽

pp. 8677-8688

Author(s):

Yan Li ◽

Liming Cao ◽

Kaiqi Gu ◽

Xinyue Wang ◽

Yunbiao Pang ◽

...

Keyword(s):

Chlorine Dioxide ◽

Gas Chromatography Mass Spectrometry ◽

Bleaching Agent ◽

Reaction Conditions ◽

Bleaching Process ◽

Ammonium Thiosulfate ◽

Adsorbable Organic Halides ◽

Organic Halides ◽

Effective Reduction ◽

Optimal Reaction

Reducing the formation of adsorbable organic halides during chlorine dioxide bleaching (the first stage chlorine dioxide bleaching, D0) is necessary to obtain clean bleaching processes. A new bleaching agent, ammonium thiosulfate (AT), was investigated to determine its potential for reducing the amount of adsorbable organic halides (AOX). Upon investigating the optimal reaction conditions for an effective reduction in AOX, the authors determined that adding 0.20% of AT 10 min after the beginning of the bleaching reaction, while maintaining a pH of 4 and a temperature of 70°C, yielded the best results. Under these conditions, AOX formation decreased by 22.0%. The bleaching effluent after the addition of AT was analyzed via gas chromatography-mass spectrometry, which showed an inhibited production rate of chlorobenzene and chlorophenol, which are both highly toxic and difficult-to-degrade compounds. Therefore, AT not only reduces AOX formation during the bleaching process, but also minimizes the difficulty of treating bleaching effluent. The results of this study provided a new, clean method for reducing AOX formation during chlorine dioxide bleaching.

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Kinetics of AOX Formation in Chlorine Dioxide Bleaching of Bagasse Pulp

BioResources ◽

10.15376/biores.9.3.5604-5614 ◽

2014 ◽

Vol 9 (3) ◽

Cited By ~ 9

Author(s):

Shuangxi Nie ◽

Shuangquan Yao ◽

Chengrong Qin ◽

Kecheng Li ◽

Xinliang Liu ◽

...

Keyword(s):

Chlorine Dioxide ◽

Kinetics Of ◽

Bagasse Pulp

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Toxicity and recalcitrant compound removal from bleaching pulp plant effluents by an integrated system: anaerobic packed-bed bioreactor and ozone

Water Science & Technology ◽

10.2166/wst.2010.794 ◽

2010 ◽

Vol 61 (1) ◽

pp. 199-205 ◽

Cited By ~ 2

Author(s):

T. R. Chaparro ◽

C. M. Botta ◽

E. C. Pires

Keyword(s):

Pulp Mill ◽

Packed Bed ◽

Ultraviolet Absorption ◽

Integrated System ◽

Packed Bed Bioreactor ◽

Cellulose Pulp ◽

Adsorbable Organic Halides ◽

Organic Halides ◽

Before And After ◽

Absorption Measurements

Effluents originated in cellulose pulp manufacturing processes are usually toxic and recalcitrant, specially the bleaching effluents, which exhibit high contents of aromatic compounds (e.g. residual lignin derivates). Although biological processes are normally used, their efficiency for the removal of toxic lignin derivates is low. The toxicity and recalcitrance of a bleached Kraft pulp mill were assessed through bioassays and ultraviolet absorption measurements, i.e. acid soluble lignin (ASL), UV280, and specific ultraviolet absorption (SUVA), before and after treatment by an integrated system comprised of an anaerobic packed-bed bioreactor and oxidation step with ozone. Furthermore, adsorbable organic halides (AOX) were measured. The results demonstrated not only that the toxic recalcitrant compounds can be removed successfully using integrated system, but also the ultraviolet absorption measurements can be an interesting control-parameter in a wastewater treatment.

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Effects and Kinetics of Chlorine Dioxide Removal Microcystin-RR

2009 3rd International Conference on Bioinformatics and Biomedical Engineering ◽

10.1109/icbbe.2009.5162728 ◽

2009 ◽

Author(s):

Ming-Song Wu ◽

Ying Ji ◽

Jun-Li Huang ◽

Jiao Fu ◽

Yu-Ling Zhang ◽

...

Keyword(s):

Chlorine Dioxide ◽

Kinetics Of

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The effects of oxygen delignification, complete chloride dioxide substitution, and biological treatment on bleached kraft mill effluent quality

Water Science & Technology ◽

10.2166/wst.1997.0468 ◽

1997 ◽

Vol 35 (2-3) ◽

pp. 1-6 ◽

Cited By ~ 1

Author(s):

Mark M. Hasegawa ◽

Douglas A. Barton

Keyword(s):

Biological Treatment ◽

Oxygen Delignification ◽

Effluent Quality ◽

Biological Removal ◽

Adsorbable Organic Halides ◽

Treatment Conditions ◽

Organic Halides ◽

Percent Confidence Level ◽

Percent Increase ◽

Kraft Mill Effluent

The effects of bleaching modifications on the biotreatability of the resulting Adsorbable Organic Halides (AOX) were studied using laboratory-scale bioreactors and mill-scale bleach plant filtrates. Under conventional pulping/bleaching conditions, biological removal of AOX averaged 40 percent. After modification to oxygen delignification and complete ClO2 substitution, the removal efficiency increased to 47 percent. Under the treatment conditions employed, the eight percent increase was found to be statistically significant at a 95 percent confidence level. These results indicate that AOX biotreatability efficiencies following bleaching sequence modifications to oxygen delignification and complete ClO2 substitution remain at least as high as those observed prior to such modifications.

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