Paper pulp effect

Chlorine Dioxide. Like ozone, chlorine dioxide [10049-04-4] is a powerflil oxidant. It is usually generated as used. It has been used for disinfecting drinking water and bleaching paper pulp. Its effectiveness in killing microorganisms is well documented (305,306), and it has received recent study as a gas to sterilize medical devices. It requites 50% rh or higher to be effective. Bacterial cells had a D-value of 2.6 min and spores of 24 min (307). 

In the pulp and paper industry, anionic and cationic acrylamide polymers are used as chemical additives or processing aids. The positive effect is achieved due to a fuller retention of the filler (basically kaoline) in the paper pulp, so that the structure of the paper sheet surface layer improves. Copolymers of acrylamide with vi-nylamine not only attach better qualities to the surface layer of.paper, they also add to the tensile properties of paper in the wet state. Paper reinforcement with anionic polymers is due to the formation of complexes between the polymer additive and ions of Cr and Cu incorporated in the paper pulp. The direct effect of acrylamide polymers on strength increases and improved surface properties of paper sheets is accompanied by a fuller extraction of metallic ions (iron and cobalt, in addition to those mentioned above), which improves effluent water quality. 

The first reports on the drag reduction phenomenon are found in publications by Blatch (1906), Forrest (1931), as well as by Brautlecht (1933), who measured the flow behaviour of paper pulps. In independent studies made by Mysels (1949) and Toms (1948) this phenomenon was observed in the turbulent flow of gasoline in pipes when aluminum soaps were added and, in Toms experiments, when polymethylmethacrylate in monochlorobenzene was used. The reduction of friction is therefore often termed the Toms effect . This flow behaviour is also known in the literature as the Non-Newtonian- , visco-elastic- , Texas- or Texas-Toms-effect , due to the contributions made by Texan researchers. It is also more generally known, and this term will be used in this paper exclusively, as the drag-reduction effect of flow additives. 

This chapter presents two Hazard Assessment Schemes that have been recently used to assess the relationship between laboratory sublethal toxicity data and field measurements of the Canadian pulp and paper Environmental Effects Monitoring program. The two methods are 1) the estimation of Zone of Potential Effect (ZPE) and 2) the Lab-to-Field Rating Scheme (LTF). The application of these schemes illustrates how to estimate the potential for effects in the receiving water environment (third use above). 

Sulfur dioxide is used for refrigeration and also serves as raw material for the production of sulfuric acid. It is also used as a bleaching agent in the textile and food industries. It is an effective disinfectant and is employed as such for wooden kegs and barrels and brewery apparatus and for the prevention of mold in the drying of fruits. Sulfur dioxide efficiently controls fermentation in the making of wine. It is used in the sulfite process for paper pulp, as a liquid solvent in petroleum refining, and as a raw material in many plants in place of sulfites, bisulfites, or hydrosulfites. 

In comparison, the average tree consumes only 1 ton of COz in a lifetime, and an acre of rainforest consumes about 500 tons yearly. When agribusiness, the ethylene industry, or pulp and paper corporations turn forests or rainforests into farmland, they also destroy an effective consumer of COz. The world s fastest-disappearing forests are in Indonesia, where they are cut down either to make paper pulp or to be replaced by palm oil plantations. Palm oil is mostly used to make biodiesel fuels. Tropical deforestation not only results in COz emissions (20% of the global total), but it also poisons the rivers. 

Filtration is the most straightforward, probably the oldest form of sugar liquor clarification process. Filtration is effected with plate and frame pressure-filters or some type of leaf pressure-filter such as Sweetland filters with stationary suspended circular leaves covered on both sides with filter cloth. A filter aid of some sort (diatomaceous earth, paper pulp, or kieselghur) is essential to the operation. The precipitated calcium carbonate serves as a filter aid in the carbonation process. The liquor is mixed with the filter aid and forced under pump pressure through the fabric, which retains the cake and allows the clear liquor to flow through. The retained sugar in the cake can be washed out with hot water. Filtration is no longer used as the sole means of clarification. The process is used for further clarification of the liquor from a carbonation or phosphatation process. 

Langlois, C. and Dubuc, N. (1999) Pulp and Paper Environmental Effects Monitoring (EEM). Results Synthesis for the 47 Cycle 1 Studies Conducted in Quebec. Environmental Canada, Montreal, Canada. 

Ozone has been applied successfully and extensively for water and wastewater treatment. Ozone also has been used as a safe and effective antimicrobial agent in many food applications. Other applications of ozone include soil decontamination, polymer surface modification, and bleaching paper pulps. It is recognized that for water treatment, the combined use of ozone with either biological treatment, or heterogenous catalysts, or UV and/or H2O2 makes the whole process more efficient. 

Many melodies from one cassette. Suppose that you have isolated an enzyme that digests paper pulp and have obtained its cDNA. The goal is to produce a mutant that is effective at high... 

B Marcoccia, DAI Goring, and DW Reeve. Photo-enhanced Oxygen Delignification of Softwood Kraft Pulp Effect of Some Process Variables. J Pulp Paper Sci 17 134—138, 1991. 

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