Chemistry. Ecology. Biotechnology – 2015

Chlorine Free)-technologies meet these requirements. ECF-technology is cheaper and more preferable. Due to easier bleachability and the specific properties of sulphite pulp its production is mostly suitable to implement chlorine-free bleaching schemes.

In the study for pulp bleaching the TCFscheme was used, which was developed at the Department of technology of pulp-and-paper production, PNRPU. For bleaching sulphite pulp with high content of residual lignin was used.

A modern scheme of ECF-bleaching of hard sulphite pulp comprises oxygen-alkaline delignification and chlorine dioxide bleaching. Disadvantages of using oxygen-alkaline delignification are the following: high pressure process; a need for pulp thickening; complex and expensive equipment; degradation of cellulose. Disadvantages of using chlorine dioxide are high explosiveness of chlorine dioxide; a need to construct special plants for producing chlorine dioxide because it is nontransportable; a need for titanium equipment.

The developed scheme of bleaching comprises delignification and bleaching only by hydrogen peroxide: ЕР-P-А-Р-А. New steps of this scheme are:

–oxidative alkaline treatment in the presence of hydrogen peroxide

(ЕР);

–delignification by hydrogen peroxide under alkaline conditions (P);

–treatment by acid (А) between the two alkaline steps.

Benefits of the represented TCF-scheme are the lack of organochlorine compounds in wastewater and in the final product; mild oxidative effect of hydrogen peroxide; decrease of resin and fat content in pulp; use of environmentally safe reagent; improved efficiency of the process through the implementation of “pumping” effect due alternation of acidic and alkaline steps of bleaching.

Two samples of sulphite pulp were bleached: Sample 1 – hard pulp (100 p.e., content of lignin 4.0 %); Sample 2 – soft pulp (65 p.e., content of lignin 1.7 %). Traditionally for bleaching soft pulp is used.

Bleaching results showed that the represented TCF-technology may be used for bleaching of hard pulp (sample 1) – bleached pulp had a

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whiteness of 87 % and yield of 93.5 %. However, it requires a considerable consumption of hydrogen peroxide (total consumption 6.0 % of abs. dry fiber). Bleaching of soft pulp (Sample 2) is more effective – with a total consumption of hydrogen peroxide by 3.5 %, the yield of bleached pulp is 95.3 %, whiteness – 88 %.

An important result of the bleaching of two samples is the high degree of depitching and total resin removal. Content of total resin and pitch in bleached pulp is so low (0.65 % and 2.1 mg / 100 g pulp respectively) that in these cases no pitch difficulties occur.

Qualitative characteristics of wastewater discharged to the off-site treatment facilities or into natural water bodies are one of the main aspects that justify introduction of TCF-bleaching technology into production. Currently, the requirements to wastewater are very strict.

To characterize wastewater the following indicators are usually applied: BOD5, COD, AOX (adsorbed organic compounds of chlorine).

AOX-indicator in wastewater is absent after bleaching only with hydrogen peroxide. Our research has shown that the level of contamination of wastewater (COD and BOD) after bleaching of sulphite pulp by the represented scheme meet the valid EU requirements.

УДК 623.19.47

O.V. Makhrova, D.A. Popov, O.I. Bakhireva, M.M. Sokolova

MICROBIOLOGICAL METHOD OF SOIL CLEANING

FROM PB2+, HG2+, CO2+ IONS

Perm National Research Polytechnic University

The Perm krai is producing mineral salts, brown iron ores, chromite ores, limestone, variety of precious, semi-precious gems and facing stones. Lead, mercury and cobalt are often present in those ores as secondary salts and compounds, and, because of it they can be found in indus-

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trial wastes which contaminate soil. Those ions can be transferred from soil with wastewaters to rivers, water reservoirs and water supply systems. Mercury, lead and cobalt are heavy metals which are toxic and dangerous for people and natural environment. In the nearest future it can be quite a serious problem.

The basis of that work is Diana Vullo's and Helena Ceretti's article about Pseudomonas veronii 2E, which are able to survive and effectively remove cadmium, zinc and copper ions from solution by their adsorption. In the present work lead, mercury and cobalt influence on those microorganisms functioning and their sorption ability is investigated.

Threshold limit values of those metal ions in different sectors are:

To investigate Pseudomonas veronii 2E’s sorption ability as regards lead, cobalt and mercury a method of “phytotesting” was chosen (according to methodical guidelines “MR 2.1.7.2297-07 Ranking industrial and consuming waste dangers by phytotoxity”). It is based on the seeds ability to react adequately to exogenous chemical treatment by changing its intensity of roots germination. It allows us to take its length as the index of test-function. Inhibition of root growth is the harm influence criteria. Seeds germination was realized in Petri dishes with filtering papers, where water extract of suspension was loaded. Our suspension was cultural liquid of Pseudomonas veronii 2E with additional soil contaminated by known amounts of lead, mercury and cobalt ions. This solution was rotated in environmental shaker until maximal growth time of Pseudomonas veronii 2E culture. Thus, the given culture’s ability to clean soils from Pb2+, Hg2+ and Co2+ ions is determined.

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УДК 661.152.2

O.G. Stefantzova, V.A. Rupcheva, G.R. Gaynanova, V.Z. Poylov

RESEARCH OF THE POTASSIUM CHLORIDE CONVERSION BY SULFURIC ACID IN THE VACUUM

Perm National Research Polytechnic University

The process of potassium chloride conversion by sulfuric acid is used in the technology of receiving potassium sulfate fertilizers for the production of potassium hydrosulfate that is processed further to get finished fertilizer. The production of the potassium sulfate fertilizers is very promising for the potassium industry development. The main advantage of these fertilizers is an opportunity of using them for plants not enduring the chlorine excess. The accumulation of chloride-ions in the ground might have some negative consequences including reduction of harvest or salting of the ground. The muriatic acid is a byproduct in this process. It can be applied in chemical, medical and oil industry and also in ferrous and nonferrous metallurgy.

The conversion of potassium chloride by sulfuric acid proceeds according to the chemical reaction:

The process of the potassium chloride suspension conversion using sulfuric acid in the vacuum has been researched in this work. The cyclone dust of potassium chloride (it is a substandard product of Uralkalii) und sulfuric acid (produced by «Lukoil-Permnefteorgsintez») were used as a potassium-containing feedstock. The process has been carried out at the boiling temperature of the suspension, at the constant rate of stirring 500 turnovers a minute during 1 hour. The ratio KCl/H2O=1:2 had been used in the conversion suspension, and the excess of sulfuric acid was 10 % of stoichiometry. The application of vacuum reduced the boiling tempera-

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ture of the potassium chloride suspension in the process of conversion and as a result the temperature of the process. The boiling temperature of the potassium chloride suspension at different values of pressure in the system under research is presented in Table 1.

Table 1

Boiling temperature of the potassium chloride suspension at different values of pressure in the system under research

Moreover, the application of vacuum in the conversion of the suspension of the cyclone dust of potassium chloride by sulfuric acid can increase the output of the main products: potassium hydrosulfate and hydrogen chloride. The output of reaction products in the conditions under research at different values of pressure is presented in Table 2.

Table 2

The output of reaction products in the conditions under research at different values of pressure

The pressure decrease in the conditions under research affects mostly the output of hydrogen chloride, because this intensifies a process of hydrogen chloride desorption. The pressure affects the output of potassium hydrosulfate indirectly (the lower pressure, the higher the water evaporation intension, and consequently the potassium hydrosulfate concentration and the exceeding saturation value). Thus, to conclude it should be noted that application of vacuum in the process of conversion of potassium chloride by sulfuric acid allows to decrease the process temperature and increase the main products output.

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УДК 661.728.2

O.A. Noskova, D.A. Volkov, O.A. Zyrjanova, N.O. Krivoschekova

PREPARATION OF POWDER CELLULOSE

USING HYDROGEN PEROXIDE

Perm National Research Polytechnic University

A powdery microcrystalline cellulose (MCC) is applied in various fields, such as pharmaceutical, cosmetics and food industries, as adsorbents and filter materials for technical applications.

Various methods for producing powdercellulose are used: a mechanical (dry grinding), thermomechanical, chemical (hydrolysis), sedimentation from solutions. As a result, cellulose powders produced. They differ by degrees of crystallinity, degree of polymerization, grain size distribution. The combination of these parameters defines scope of the powders.

The Department of technology of pulp-and-paper production, Perm State Technical University, has developed technological process of making cellulose powder for use in food, pharmaceutical and medical industries. Powder cellulose was obtained by acid hydrolysis followed by mechanical grinding. The raw materials were cotton and wood sulfite viscose pulp. Aqueous solutions of hydrochloric and nitric acids were used as hydrolyzing agents.

This work has been done to expand the raw material base for the cellulose powder by using wood cellulose of larger yields.

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Научное издание

CHEMISTRY. ECOLOGY. BIOTECHNOLOGY – 2015

ХИМИЯ. ЭКОЛОГИЯ. БИОТЕХНОЛОГИЯ – 2015

Abstracts for the Regional Conference of students and young scientists (Perm, April 21–22, 2015)

Тезисы докладов

ХVII региональной научно-практической конференции студентов и молодых ученых

(г. Пермь, 21–22 апреля 2015 г.)

Технический редактор И.Н. Жеганина

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