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 .
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.