Toxicity reduction through chemical and biological modification of spent pulp bleaching liquors

by Carlton W Dence

Publisher: Industrial Environmental Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency, Publisher: Available to the public through the National Technical Information Service in Cincinnati, Springfield, Va

Written in English
Published: Pages: 99 Downloads: 944
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Subjects:

  • Chlorophenols -- Toxicology,
  • Biological assay,
  • Chemical reactions

Edition Notes

Statementby Carlton W. Dence, Chun-Juan Wang, and Patrick R. Durkin
SeriesResearch reporting series -- EPA-600/2-80-039
ContributionsWang, Chun-Juan, 1928-, Durkin, Patrick R, Industrial Environmental Research Laboratory (Cincinnati, Ohio), Industrial Environmental Research Laboratory (Cincinnati, Ohio). Food and Wood Products Branch, College of Environmental Science and Forestry
The Physical Object
Paginationxii, 99 p. :
Number of Pages99
ID Numbers
Open LibraryOL13603666M

ENVIRONMENTAL ASPECTS OF SOME ALTERNATIVE PULP BLEACHING TECHNIQUES P. B. Belt, T. W. Joyce, and H-m. Chang Department of Wood and Paper Science North Carolina State University Raleigh, North Carolina The work upon which this publication is based was supported in part by funds provided by the Office of. Manufacture and Bleaching of Wood Pulp Wood is composed of countless indi-vidual fibers joined together as a com-mon body through the binding action of lignin compounds. Chemical pulps re-sult from dissolving these lignin binders, leaving fiber masses. Normally, the first step in the manu-facture of chemical pulp from wood is the removal of bark. Get this from a library! Environmentally benign approaches for pulp bleaching. [P Bajpai] -- Pulp and paper production has increased globally and will continue to increase in the near future. Approximately millions tons of wood pulp is produced worldwide and about millions is. Bleaching of chemical pulp is carried out in several stages. In modern mills, the bleaching starts with oxygen delignification for a reduction of the consumption of more expensive bleaching chemicals and a reduced effluent load from the bleach plant. The predominant bleaching methods are elemental chlorine free (ECF) and totally chlorine free.

  Chlorine dioxide is an ECF bleaching agent, which is used instead of elemental chlorine. The elemental chlorine bleaching has large environmental and health issues. It produces many toxic compounds as like organochlorine compounds, dioxins and furans, but the chlorine dioxide bleaching agent does not produce this chemicals. It is five to In the second step, we used a standard tissue-culture toxicity assessment technique to examine both culture medium samples for the presence of chemical toxins. In use, this system gave results which correlated well with the known clinical potential for pulpal toxicity of . Chemical pulps are produced by chemical delignification of lignocelluloses such as wood or annual non-woody plants. After pulping (e.g., kraft pulping), the remaining lignin is removed by bleaching to produce a high quality, bright paper. The goal of bleaching is to remove lignin from the pulp without a negative effect on the cellulose; for this reason, delignification should be performed in a. of bleac hing. Designed as a text book and reference book, Pulp Bleaching: P rinc iples and Practice explains what bleac hing is, why pulp is bleached, and how bleaching is done. The book is divided into eight major sections which are sub-divided into 36 chapters covering all aspects of pulp bleaching. The book also features discussions on.

Pulp bleaching is usually accomplished using a series of chemical treatments. The chemicals and the order in which they are used make up a "bleaching sequence." One of the main goals of bleaching is to mitigate the environmental impact it has on the environment. •Acute toxicity tests –Measures lethality in a 24 –96 hour period –Can be static or flow-through –Screen or Definitive –Renewal or non-renewal •Chronic Toxicity tests –Measures toxicity over a day period –Measures lethal and sub lethal (non lethal) effects –Screen or Definitive –Daily renewals required. INTRODUCTION. Pulp is the fibrous cellulosic material used in the production of paper. Wood is the principal raw material for the production of pulp; but bamboo, cotton, linen, rags, straw, bagasse, etc are also used. Chemical pulp production is the cooking of the wood raw material with g is necessary to remove the binding agents from the wood. Toxicity to the Liver As the primary organ of biotransformation, the liver is susceptible to toxicity mediated by chemical reactivity, as described above. Other agents with toxicity to the liver include: Chlorinated hydrocarbons Metals, etc. Toxicity to the Kidney Classes of compounds that are potential nephrotoxins include: Amines.

Toxicity reduction through chemical and biological modification of spent pulp bleaching liquors by Carlton W Dence Download PDF EPUB FB2

The report investigates the reduction of the toxicity of spent pulp bleaching liquors through chemical and biological modification. was determined over a range of concentrations, before and aFter modification, to determine their effect on the growth of fungi, alga and duckweed, and on.

The report investigates the reduction of the toxicity of spent pulp bleaching liquors through chemical and biological modification. Toxicity was determined over a range of concentrations, before and after modification, to determine their effect on the growth of fungi, alga and duckweed, and on the survival of Daphnia Magna.

Toxicity Reduction Through Chemical and Biological Modification of Spent Pulp Bleaching Liquors - Ebook written by Carlton W. Dence, Chun-Juan Wang, Patrick R. Durkin. Read this book using Google Play Books app on your PC, android, iOS devices. Download for offline reading, highlight, bookmark or take notes Toxicity reduction through chemical and biological modification of spent pulp bleaching liquors book you read Toxicity Reduction Through Chemical and Biological Modification of Spent.

Toxicity reduction through chemical and biological modification of spent pulp bleaching liquors. Cincinnati: Industrial Environmental Research Laboratory, Office of Research and Development, U.S. Environmental Protection Agency ; Springfield, Va.: Available to the public through the National Technical Information Service, (OCoLC) Toxicity reduction through chemical and biological modification of spent pulp bleaching liquors / By Carlton W.

Dence, Patrick R. Durkin, Chun-Juan. The enzyme solution, usually mixed with water, is allowed to react in the high-density storage tower tank for up to h prior to the subsequent chemical-bleaching steps (Figure ) (Bajpai.

The report investigates the reduction of the toxicity of spent pulp bleaching liquors through chemical and biological modification. Toxicity was determined over a range of concentrations, before and aFter modification, to determine their effect on the growth of fungi, alga and duckweed, and on the survival of Daphnia Magna.

Digested liquors from spent sulphite chemical pulping. Recovery of lignosulphonates and sugars: Organic substances with chlorine are one of the major toxic products of bleaching pulp (for whitening the paper).

Hydrogen peroxide is the most frequently used chemical for high-yield pulp bleaching when high levels of brightness are required. Mutation Research, () Elsevier MTR Summary 89 Mutagenic properties of spent bleaching liquors from sulphite pulps and a comparison with kraft pulp bleaching liquors M.

Moller 1, G.E. Carlberg 1 and N. Soteland 2 Center for Industrial Research, P.O. Box Blindern, Oslo 3, and = The Norwegian Pulp and Paper Research Institute, P.O. Box. Dence, C., C.J. Wang, and P. Durkin. Toxicity reduction through chemical and biological modification of spent pulp bleaching liquors.

U.S. Environmental Protection Agency, Publication No. EPA/ Cincinnati, Ohio. The pulp and paper industry in Canada contributes significant effluent discharges to surface and marine waters. Chlorine and chlorine compounds are used in the bleaching of pulp.

Dence CV, Wang CJ, Durkin PR () Toxicity Reduction through Chemical and Biological Modification of Spent Pulp Bleanching Liquors, EPA ReportUS EPA, Athens Google Scholar Walden CC, Howard TE, Tappi J () 60 (1): Google Scholar Pulp and Paper Canada 79 (10): TT Davis, J.C. and B.J. Mason.

Bioassay procedures to evaluate the acute toxicity of neutralized bleached kraft pulp mill effluent to pacific salmon. Fish. Res. Brd. Can. Dence, C.W. et al. Toxicity reduction through chemical and biological modification of spent pulp bleaching.

Toxicity Reduction Through Chemical & Biological Modification of Spent Pulp Bleaching Liquor by Carlton W. Dence, Chun-Juan Wang & Patrick R. Durkin Use of Krofta Floated Sludge as Feed for Aeration by Priyanshu, Md.

Mobasshir Habib, Abhinav Srivastava & DK Singhal Zero Discharge by TOP OF THE PAGE. By far the greatest proportion of bleached chemical pulp is produced by the kraft process (about 88 percent of the pulp bleached in was kraft pulp).

Very little mechanical pulp has been bleached in the past, however, this is currently changing. Mechani-cal pulp bleaching is. MECHANICAL PULP BLEACHING Dr. THOMAS Q. HU FPInnovations – Pulp and Paper Division Wesbrook Mall, Vancouver, BC V6S 2L9 Tel.: Pulp and paper waste water is one of the major sources of industrial water pollution.

This study tested the suitability of ceramic tubular membrane technology as an alternative to conventional waste water treatment in the pulp and paper industry. In this context, in series batch and semi-batch membrane processes comprising microfiltration, ultrafiltration and nanofiltration, ceramic membranes.

Toxicity Reduction Evaluation Case Summary for The role of the chemical additives in pulp and paper efI,luents can be readily determined through bench-scale testing using the U.S.

Environmental Protection Agency’s (USEPA) toxicity identification improvements in water management and biological treatment. Additional TRE examples. Use of biotechnology in pulp bleaching has attracted considerable attention and achieved interesting results in recent years.

Enzymes of the hemicellulolytic type, particularly xylan-attacking enzymes, xylanases are now used commercially in the mills for pulp treatment and subsequent incorporation into bleach sequences. Bleaching: A Working Definition Removal of colored residual lignin from chemical pulp (usually kraft) to increase its brightness, cleanliness and other desirable properties, while preserving the strength (cellulose integrity) and carbohydrate yield (cellulose and hemicellulose) of the unbleached fiber, with due regard for potential.

REDUCTION OF THE RECALCITRANT COD OF HIGH YIELD PULP MILLS EFFLUENTS BY AOP. PART 1. COMBINATION OF OZONE AND ACTIVATED SLUDGE Pedro R.

Meza, a Fernando E. Felissia,b and Maria Cristina Area b,c The aim of this work was to study the effect of ozone, either alone or combined with an activated sludge system, on the reduction of the.

Pulp and paper industry is considered as one of the most polluter industry in the world (Thompson et al., ; Sumathi & Hung, ). The production process consists two main steps: pulping and bleaching. Pulping is the initial stage and the source of the most pollutant of this industry.

EPB1 EPA EPA EPB1 EP B1 EP B1 EP B1 EP A EP A EP A EP A EP A EP A EP B1 EP B1 EP B1 Authority EP European Patent Office Prior art keywords pulp bleaching procedure chlorine oxygen Prior art date Legal status (The. digesting wood in a pulping liquor followed by washing, bleaching, and extracting of the pulp, and concentrating and subjecting the liquor to reducing conditions to recover chemicals, wherein at least part of the wash water obtained from washing bleached cellulosic pulp or from washing bleached and extracted cellulosic pulp in employed to wash unbleached cellulosic pulp thereby providing.

For example, in the bleaching stage, which consists of several intermediate washing cycles using oxygen and various chemicals such as hydrogen peroxide and ozone, the importance of pulp washing must be considered because removal of the wood resin components and metal salts is not efficient in the closed bleaching process, i.e., recycling the.

Most chemical pulp bleaching sequences contain an oxygen-alkali extraction stage to lower the cost of chemical pulp bleaching. The stage has been improved since its introduction in by increasing the temperature, the pressure and the retention time [21].

Hydrogen peroxide in ECF bleaching. microorganisms by physical or chemical means When a bacterial cell comes into contact with chlorine dioxide it donates an electron from its cell wall, thereby creating a breach in the cell wall through which cell contents pass in an attempt to bring the concentrations on either side of the cell membrane to equilibrium.

The cell dies through lysis. kraft pulp mills. Measurements of dioxin levels in the three sources of pollution (pulp, effluent, and sludge) are being conducted at all U.S. chemical pulp mills using chlorine bleach under the joint sponsorship of EPA and the American paper industry.

The results of these studies and others underway in Canada and Europe will Sustainable pulp and paper manufacturing requires a holistic view of the manufacturing process. During the last decade, there have been revolutionary technical developments in pulping, bleaching and chemical recovery technology.

These developments have made it possible to further reduce loads in effluents and airborne emissions. Toxicity reduction through chemical and biological modification of spent pulp bleaching liquors / (Cincinnati, Ohio: Industrial Environmental Research Laboratory, Office of Research and Development, U.S.

Environmental Protection Agency, []), by Carlton W. Dence, Patrick R. Durkin, Chun-Juan Wang, College of Environmental Science and. Optimal dose of Mg(OH)2 gave brightness result of %-ISO, just one percent lower than using conventional chemicals. In return % dose of Mg(OH)2 left organic compounds mostly intact and so TOC of filtrate was only ppm.

In other words, replacing NaOH and Na2SiO 3 with Mg(OH)2 alone lowered TOC by almost ppm, more than one half. It was also found that using Mg(OH)2 .The book Our Stolen Future was important because it _____. At what concentration does this contaminant have its smallest toxic effect?

microgram per Kg. most chemicals are water soluble so they enter these organisms through drinking or skin absorption. The graph in (c) is one type that may occur when a test animal is exposed to a(n.Semi-Chemical Pulping Liquors The compositions of typical NSSC fresh and spent pulping liquors are presented hi Tables andrespectively (11).

Toxicity of Pulping Liquors The toxicity of wood pulping liquors has been extensively studied for many years.