Chemistry. Ecology. Biotechnology

УДК 539.216

E.E. Alikina, I.A. Permjakova, V.V. Volkhin

STUDY OF WATER EFFECT ON THE ETHERIFICATION

OF BUTANOL AND OLEIC ACID

Perm National Research Polytechnic University

Today, the development and introduction of biodegradable substances used as solvents is a promising tendency.

Biodegradable solvents are ''eco-chemical'', and eventually they might replace conventional ones. Biodegradable esters of higher fatty acids and alcohols are considered as solvents. They are synthesized from vegetable oils and alimentary animal fats. Therefore, the problem of using non-alimentary raw materials such as sub-standard plant oils and waste oils for the synthesis arises. However, the processing of substandard oil has its drawbacks.

Waste vegetable oils contain from 3 to 40% of free fatty acids (FFA). When neutralized by alkaline catalysts, soaps that impede the subsequent separation and purification of the reaction products are formed. In order to reduce the initial FFA content in the oil, it is proposed to carry out etherification using acid catalysis (H2SO4) and methanol.

The process ends with transesterification of triacylglycerols oils using alkaline catalysis. In this case, transetherification and etherification form the same product - esters of lower alcohols and higher fatty acids, which are components of the solvent.

A significant drawback of this technology is the low rate of etherification reaction with acid catalysis (H2SO4).

In this study we aimed at optimizing the flow of the etherification reaction in the oleic acid-butanol system with an acid catalyst.

As a result of the experiment, relations of conversion degree of oleic acid to ester were set.

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The study of the produced ether properties was conducted, which showed that it tends to biodegradation and is the solvent for vegetable oils and animal fats.

УДК 549.755.21

A.V. Shutova, G.V. Leontjevа, V.V. Volkhin

INFLUENCE OF SURFACE-ACTIVE SUBSTANCES ON THE SORPTION OF NICKEL IONS

Perm National Research Polytechnic University

Struvite, MgNH4PO4 · 6H2O, is recommended for use as a soil improver – stabilizer in the remediation of soils contaminated with heavy metals (TM). However, the absorption of TM ions in the soil solution may be complicated due to the presence of surface-active substances (SAS) that are produced by microorganisms – oil destructors. Under conditions of soil pollution with oil and oil products the surfactant may be adsorbed on a surface in a liquid-solid system and create difficulties, for example, to Mg2+ → Ni2+ ion exchange with struvite.

The aim of this study was to determine the role of surfactants in Ni 2+ ions sorption.

At this stage, research was carried out with SAS, which properties are clearly expressed and well reproducible, namely with cationic surfactant – bromide hexadecyltrimethylammonium (STAV), anionic – laurilsulfat sodium (SDS), and a nonionic – polyoxyethylene (20) sorbitan monolaurate (Tween 20). This choice of surfactants was motivated by struvite properties: its particles acquire a negative charge in a solution with an excess of HPO42– ions, positive with Ni2+ ions and excess Mg2+ and an almost neutral in the field with no excess of anions or cations in the liquid phase. Given the morphologies of struvite, it can be expected that the excess anions and cations will affect the morphology and size of

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struvite crystals in various ways, and possibly on the metabolic processes with these crystals involved.

The experimental results confirmed that the studied SAS samples have a significant impact on the sorption of Ni2+ ions, particularly at the stage of recrystallization. Surfactant effect becomes significant in a solution with concentration of 2.5 × 10–3 or higher. At a given concentration, the size of struvite surfactant crystals that participated in the process of adsorption has markedly decreased, and this is particularly evident in the presence of SDS. Under the SAS influence the sorption of Ni2+ ions is also reduced. Now the analysis of the factors that weaken the surfactants effect is being conducted.

УДК 623.19.47

M.A. Chudinova, E.A. Farberova, A.V. Vinogradova

IMMOBILIZATION OF MICROORGANISM CELLS ON CARBON SORBENTS TO CREATE A BIOCATALYST TO PURIFY PHENOL-CONTAINING WASTEWATER

Perm National Research Polytechnic University

JSC "Sorbent" is a leader in the Russian market of activated carbons production.

In general, during technological process of obtaining wood-based activated carbons by artificial means waste activation gases are formed. Such gases require purification. Activation gases enter the cyclone scrubber filled with water where the traces of solid and soluble admixtures are removed. The waste slurry water is subject to purification as well, for it contains a variety of impurities, including phenolic compounds. Solid sediments usually stain on the walls and the bottom of the scrubber, which makes it difficult to clean the unit.

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The purpose of this study was to create a biocatalyst for the purification of wastewater sludge.

The objectives of the study were:

1.Synthesis of oil-oxidizing microorganisms from a slurry water and study of their characteristics;

2.Selection and analysis of activated carbons of various nature (granulated, crushed, fibrous of plant raw materials and coal);

3.Testing of microbial cells immobilizing parameters on the surface of the selected coal;

4.Study of the holding capacity of coal in relation to microorganisms cells;

5.Study of bio-oxidizing properties of biosorbents used for sludge purification;

To achieve this, we studied the composition of the sludge water, taken from the scrubber after activation gas purification. Water is a solution containing a suspension of solid particles of not fully activated coal.

It is known that carbonaceous materials may serve as a nutrient medium for a number of microorganisms. After purification of the sludge water, individual colonies of microorganisms were extracted. Given the composition of the sludge water, it is obvious that these are hydrocarbon oxidizing microorganisms. Cells of microorganisms isolated from the water were cultivated by batch culture method. Their morphological description and microscopy was carried out.

Cells of the extracted cultures are rod-shaped, with a slightly curved, thin membrane. Microorganisms that grown on the surface of agar medium are of an indefinite slime shape, with the colonies of a white colour.

The growth curve shows that the culture has a lag period of 18 hours, during which it adapts to culture conditions: the exponential growth phase is of 30 hours, the stationary growth phase continued for 24 hours, and the specific speed of growth is equal to 0.045 h–1.

The experiments were conducted to explore a possibility of phenol removal from slurry water by introducing the selected cell culture. As a result, it has shown a fourfold reduction of the phenols in treated water.

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Active carbons of different particle size and shape, quality of raw materials, preparation conditions and the characteristics of the porous structure were selected as a basis for biocatalyst.

A study of comparative adsorption capacity of activated carbons in the sludge water purification was conducted. COD of the water samples was 1200 mgO2/dm3. Before the adsorption tests, slurry water samples were centrifuged and it was found that its COD dropped to 800 mgO2/dm3. To analyze the sorption properties, activated carbons were put under static conditions by immersing the coal in a given sample volume of water for a time from 30 to 180 minutes, with continuous stirring. The highest degree of impurities removed from the sludge water was found in active coal of AG-3 and AG-5 grades, as well as in activated coconut based carbon.

Immobilization of microbial cells on the surface of activated carbons was carried out by the means of the static method.

We studied the retention capacity of active carbons of different brands in relation to the cells of microorganisms, and also determined a comparative biocatalytic activity of the carbon biocatalysts in the slurry water purification.

УДК 574.24

A. Furina, A. Maksimov, V. Basov

APPLICATION OF PENICILLIUM GENUS FUNGI OXIDASE ENZYMES FOR TREATMENT OF ACTIVATED SLUDGE

Perm National Research Polytechnic University

Excess activated sludge is a mixture of primary clarifier’s sediment and biomass of activated sludge’s microorganisms. It contains organic (80%) and mineral components (20%) and has a moisture content of about 80%. Excess activated sludge may contain a variety of

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organic and inorganic contaminants and pathogens (microorganisms, helminth eggs). A number of volatile organic compounds are formed in the activated sludge. These substances cause the unpleasant smell of excess activated sludge.

To date, the main disposal method of excess sludge is its location on the silt maps in Russia. Silt maps are pollution sources of surface water and groundwater. Sludge sites require large areas. In addition, excess sludge has a sharp unpleasant smell (especially in summer), which can be felt in nearby towns. Therefore, the storage of activated sludge in silt maps does not meet modern environmental and technical requirements.

In this study, we consider the following issues: unpleasant smell of activated sludge, a relatively large amount of sludge and its high humidity.

Following the analysis of the published data, we suggested that the oxidase enzymes contained in the mycelium of Penicillium genus fungi, can be used to solve these problems. We got the biomass of microscopic fungi (we used submerged cultivation in a Capek liquid medium) to test this assumption. The enzymes were isolated by autolysis (temperature 45 °C). We determined the activity of these enzymes using photocolorimeter (at a wavelength of 420 nm) in the rate of oxidation of pyrocatechol (10 mM) in the acetate buffer (pH = 5). Unit oxidase activity is a change in the optical density of the reaction mixture for 1 min on 1 ml of culture filtrate.

The purpose of the further research is an experimental evaluation of the oxidases influence on the intensity of volatile organic compounds emission, causing unpleasant smell of activated sludge, as well as a study of oxidases influence on characteristics such as moisture, filterability and settling rate.

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УДК 539.216

E.A. Kasatkina, I.A. Permjakova, V.V. Volkhin

BIODEGRADABLE SOLVENTS BASED

OF ESTERS ETHANOL AND HIGHER FATTY ACIDS

Perm National Research Polytechnic University

Solvent is a chemical substance that can form a solution with another substance. Solvents are used as a medium for passage of chemical reactions and for other technological purposes. As technological means the solvents are used in paint and varnish industry, textile, pharmaceutical, perfumery and medical industry. The solvents are widely used for defatting metals and their alloys in cold treatment and in the liquid-vapor degreasing. Organic solvents are also used as additives for biodiesel.

Esters start being widely applied as solvents. They are obtained by esterification of fatty acids and alcohol in conditions of acid catalysis:

RCOOH + R’OH RCOOR' + Н2О

However, many solvents are toxic and resistant to the environment, therefore, the interest to obtaining biodegradable solvents based on ethanol and esters of higher fatty acids increased but methods of their synthesis are still poorly developed.

The search of optimal conditions for obtaining fatty acid esters taking account of phase equilibrium in the systems involved became popular. The objectives of this study are:

1)Experiments to determine phase composition systems OlA-EtOH, where OlA is the oleic acid and EtOH is the ethanol, in the presence of

H2SO4 as a catalyst. It is shown that the system may be in heterogeneous or homogeneous state.

2)Study of etherification reaction in the system OIA-EtOH in the presence of acid catalyst.

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3) Implementation of synthesis esters – ethyl oleate and evaluation of its properties as a solvent and biodegradable substance. The dependence of the synthesis results is set from a number of factors. It is shown that ethyloleat is capable of dissolving vegetable fats and oils. The increased ability of ethyloleates to biodegradation is confirmed.

УДК 623.19.47

O.V. Makhrova, O.I. Bakhireva, M.M. Sokolova

MICROBIOLOGICAL METHOD OF CLEANING

SOIL FROM IONS OF HEAVY METALS

Perm National Research Polytechnical University

Perm krai produces mineral salts, brown iron ores, chromite ores, limestone, variety of precious, semi-precious gems and facing stones. Lead is often a part of those ores as а secondary salt and a compound and as a result it can be found in industrial wastes that contaminate soil. Those ions can be transferred from soil with wastewaters to rivers, water reservoirs and water supply systems. Lead is a heavy metal that can be toxic and dangerous for people and natural environment. In the nearest future it can be quite a serious problem.

This work is based on Diana Vullo's and Helena Ceretti's article about Pseudomonas veronii 2E bacteria, which are able to survive and effectively sorb cadmium, zinc and copper ions. In this work we study how lead affects those microorganisms, their vital activity and their ability to adsorb these ions.

According to methodical guideline “MR 2.1.7.2297-07 Industrial and consuming wastes danger rank justification by phytotoxity”, we chose “phytotesting” method to test the lead sorption ability of Pseudomonas veronii 2E. It is based on the ability of

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seeds to react adequately to exogenous chemical treatment by changing intensity of their roots germination. It allows us to take its length as the index of test-function. Inhibition of root growth is the harm influence criterion. Seeds germination was realized in Petri dishes with filtering papers, where water extract of suspension was added. Our suspension was a cultural liquid of Pseudomonas veronii 2E with additional soil contaminated by the known amounts of lead ions. This solution was rotated in an environmental shaker until maximal growth of Pseudomonas veronii 2E was reached. This experiment allowed us to test if these bacteria can be used to cleanse soils of Pb2+ ions.

Phytotest showed us that the growth of oat seed with germination at 45% in distilled water is inhibited by the presence of lead ions with concentration of 50 mg/kg of air dry soil, but is not stopped completely. Seed germination is 23% when processing the soil extract obtained from soil that was previously treated with a solution of a lead salt. When soil is pre-treated with the culture liquid that contains Pseudomonas veronii 2E cells, germination rate is 56%, so presence of cells and their metabolites on the seeds growth has a positive effect on soil. When soil is pre-treated with lead and the culture fluid that contains a cell culture of Pseudomonas veronii 2E, inhibitory effect is not observed, and these seeds have maximum germination rate at 73% and maximum length of roots in the whole series of experiments.

Therefore, we have proved the sorption effect of culture Pseudomonas veronii 2E on lead ions in sufficiently high concentrations.

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УДК 579.26

A.G. Azarova, O.I. Bakhireva, E.A. Vorontsova

THE REMOVAL OF ZINC AND MANGANESE IONS FROM INDUSTRIAL SOLUTIONS AND WASTEWATER

Perm National Research Polytechnic University

The pollution of fresh water with heavy metal ions has become a serious problem due to anthropogenic activities. Essentially, heavy metals have no effective self-purification mechanisms. They are just moved from one pond to the other, interacting with various organisms and leaving evident fallouts of this interaction all around.

Today, industrial emissions are the main sources of fresh water pollution. Metals can infiltrate natural waters along with the industrial waters that contain chemical compounds and traces of elements, with rainwater, filtering through dumps, and also due to emergency cases at the chemical plants and storages.

In surface waters, manganese is on the first content level among all other microelements and zinc is on the second. In lakes located in the area near the zinc smeltering plants the concentration of dissolved zinc exceeds 100 mg/l. According to the information available, the maninduced zinc emissions are 700% more than naturally occurring ones.

Increased accumulation of zinc may lead to metal deficiency in living organisms. It initiates repelling of enzymatic reactions. Zinc toxicity leads to increased lactic acid production and consequently to increased blood pH and kidney dysfunction.

Non-clarified foul water from manganese ore-processing plants contains 20-35 mg/l of manganese. The metal has a mutagenic impact on warm-blooded animals. If it has a concentration of at least 50 mg/l, it becomes toxic to fish and lower aquatic organisms.

The purpose of this work is to select microorganism cultures which will react to heavy metal ions (Zn2+ and Mn2+) with stability and absorption capacity.

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