Water and water purification technologies

Scientific and technical news

CARBON NANOTUBES WATER PURIFICATION (REVIEW)

I.N. Ivanenko

NationalTechnicalUniversityof Ukraine“KPI”, Kiev, Ukraine

irinaivanenko@hotmail.com

 Article describes latest published in literature data on the catalytic and adsorption properties of singlwalled and multiwalled carbon nanotubes and their oxidized and modified forms. Results describes showed high catalytic activity of nanotubes in oxidation of phenol, p-toluidine, aniline; decomposition of oxalic acid with ozone; hydrogenation and hydroxylation of aromatic hydrocarbons and others. Data presents, confirming that adsorption takes place on the outer and on the inner surfaces of singlwalled and multiwalled carbon nanotubes. Shows adsorption of natural organic matter (river, lake, peat, soil humic and fulvic acids); direct Congo red, reactive green and golden yellow dyes by multiwalled carbon nanotubes. Proved, functionalized carbon nanotubes are effective at removing nitrophenol and toxic hexavalent chromium from aqueous solutions, and modified FeOx nanotubes established well in absorption of arsenic compounds from wastewater of textile industry. Critically considered the ability of original and modified in various ways carbon nanotubes to influence on membranes rate fouling for persistent and long-term operation of drinking water filters. Shown, using of carbon nanotubes for immobilization on traditional commercial membranes surface to improve efficiency of their work for preparation of drinking water, membrane purification of highly concentrated wastewater from pharmaceutical production from volatile organic compounds.

Keywords: carbon nanotube, catalytic properties, adsorption, membrane.

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06.04.2016 at 8:00 pm

DEFINITION OF LAW DISTRIBUTION OF PHYTOPLANKTON IN THE SOURCE WATER AND FILTRAT

D. Charniy1, I. Kuzmych 2
1 -  Institute of Water Problems and Land Reclamation NAASU, Kyiv, Ukraine
e-mail: dmitriych10@gmail.com

2 – Kyiv National University of Construction and Architecture, Kyiv, Ukraine
e-mail: egor_ks@i.ua

Based on data obtained in the filter results at the foamed polystyrene loading of water  which contains of  phytoplankton  have conducted research the on accordance  of six  laws of distributions. Found that the distribution of phytoplankton in the input and the source water corresponds to a normal distribution.

Keywords: phytoplankton, filtration, distribution law, the water intake of treatment facilities.

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06.04.2016 at 7:54 pm

CFD SIMULATION OF THE HORIZONTAL SETTLER WITH FIN WORK

N.N. Biliaiev, V.A. Kozachyna

Dnepropetrovsk National University of Railway Transport named after V. Lazaryan, Dnepropetrovsk,Ukraine

gidravlika2013@mail.ru

 Horizontal settlers are one of the most important elements in the technological scheme for drinking water preparing and waste water treatment. Their use is associated with the possibility to pass a sufficiently large volume of water. When remodeling or designing horizontal tanks there is an important task to evaluate their effectiveness. Calculation of the efficiency of the settler can be made by mathematical modeling. Currently used models and methods do not allow take into account the shape of the sump and the various design features. In this paper we consider the construction of a numerical model to evaluate the effectiveness of horizontal settler modified structure. The model is based on equations of motion of an ideal fluid and mass transfer equation. For numerical simulation the finite difference schemes are used. The numerical calculation is carried out on a rectangular grid. For the formation of the computational domain markers are used. The model allows calculate the clarification process in the sump using computers small and medium power. Calculation time of one variant of the problem is a few seconds. The results of a computational experiment are presented.

Keywords: numerical simulation, horizontal settler, CFD model.

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06.04.2016 at 7:47 pm

PROSPECTS FOR THE USE OF WASTE ALUMINA PRODUCTION IN WATER TREATMENT TECHNOLOGY

Kosogina I.V.

NationalTechnicalUniversityofUkraine“KPI”,Kiev,Ukraine

kosogina@email.ua

 Сoagulant was obtained from waste alumina production (“red mud”). The analysis of samples of “red mud” and activated with sulfuric acid forms, set their phase and elemental compositions. On the basis of analysis identified physical and chemical laws of acid activation of “red mud”; established the conditions for obtaining reagents from the “red mud”, which are expressed coagulation properties. The high efficiency of the application of the modified “red mud” as a coagulant for wastewater from dye “active bright blue” with the concentration of 10 mg/dm3. The degree of purification is 95 %.

Keywords: “red mud”, acid activation, wastewater, dyes, coagulation.

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06.04.2016 at 7:36 pm

QUALITY MANAGEMENT OF WATERS OF THE DANUBE LAKES ON EXAMPLE OF THE YALPUG-KUGURLUY LAKE

T.V. Kotova 

KievNationalUniversityof Building and Architecture,Kiev

e-mail: tvkotova@ukr.net

 The paper presents the results and used mathematical models for solving water and freshwater ecological status (on example of the Ialpug-Kugurluy lake of Danubian lake system). An urgent task control incoming and outgoing components of the water balance of lakes in order to establish the optimal markers for maintaining the quality of water in the reservoirs was considered. Schedule changes in salinity for the Yalrug-Kugurluy lake was built for the time interval 1974 – 2011 years. The water balance equation for this reservoir was proposed.

Keywords: water-salt balance, quality management of waters, hydrochemical regime, normal water level, dead volume level.

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06.04.2016 at 7:32 pm

GEOCHEMICAL PECULIARITIES OF GROUNDWATER WITHIN THE TERRITORY OF LVIV TROUGH

R.P. Pankiv, M.V. Kost, I.I. Sakhhyuk, O.M. Maikut,

O.B. Mandzya, I.P. Navrotska, R.P. Kozak

Institute of Geology and Geochemistry of Combustible Minerals of NAS, Lviv, Ukraine

e-mail: M_Kost_2007@ukr.net 

In this paper based on the definition of indicators of the chemical composition of the groundwater its ecological status and degree of contamination were appraised. Increased content of nitrates, silicon, alkalinity and high values of the general hardness were fixed. Deviations of physiological full value of the mineral composition of drinking water from guideline values were revealed. It was established that the formation of geochemical composition of ground water was due to the influence of factors of geological, physical, chemical and man-made origin. Recommendations for reduction of pollution of drinking water and improvement its quality were cited.

Key words: groundwater, geochemical features, degree of contamination, the correlation coefficient, factors of influence.

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06.04.2016 at 7:22 pm

METHOD OF CALCULATING THE HYBRID CIRCUITS CONDITIONING PURGE WATER CIRCULATING COOLING SYSTEMS

V.P. Kishnevsky V.V. Chichenin I.D. Shulyak E.V. Kishnevsky

Odessanational polytechnic university “ONPU”Odessa,Ukraine

Email: twf61@yandex.ru

It is shown that the water chemistry mode of recirculating cooling system without scale ensures high costs of additional water and blowdown (about 300 m3/h per 1000MW of installed capacity).

To reduce the discharge of blowdown water to the environment a method and calculation algorithm for a number of schemes with blowdown water recirculation through clarifiers are proposed. Method of calculation the water chemistry mode of recirculating cooling system is to determine calcium hardness and predict deposit thickness for the estimated operation time of the plant. The proposed method allows to calculate not only calcium hardness, but the pH, concentration of other ions, including sulphates.

We have shown that by using structural schemes of complex recirculating cooling system with recirculation blowdown water through a clarifier the concentration of sulfates that can reach critical values in terms of intensification of power equipment corrosion.

To correct critical sulphates concentration an appropriate methodology of water exchange is suggested. The proposed methodology and calculation algorithm enable the justification of blowdown water sampling points selection and flow of side-stream supplied to the recirculation and water exchange, depending on the water-chemical conditions and the quality of the source water. Calculations are presented for two water chemistry modes.

Keywords: circulating cooling system, pre-treatment, extra water, circulating water.

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06.04.2016 at 7:18 pm

THE HYDRATION THEORY OF STABILITY AQUEOUS COLLOIDO-DISPERSION SYSTEMS

A.K. Zapolzkiy

Zhytomyr National Agro-Economic University, Zhytomyr, Ukraine

e-mail: zak-38@ukr.net

The proposed hydration theory of stability aqueous colloidal-dispersion systems as an alternative to the theory of the electrical double layer. Modern ideas of the structure and conductivity of water led to the conclusion that dissolved substances, including strong electrolytes, not spontaneously decompose into ions. Dissociation of molecules of the dissolved substance into ions is carried out only during chemical interaction with water clusters and products of their interaction. Since in the aqueous solution (the dispersing medium) free ions do not exist, that also can’t be formed double electronic layer (DEL) around the colloido-dispersion phase (micelles).

In the dispersing medium (water) molecules of the dissolved substance and suspended colloidal particles stay in the hydrated state. The stability of colloidal systems “solid phase - water” should be considered from a position of hydration balance in system ” particle - water”, considering the interaction as part with water clusters, and the last among themselves.

Electric charge of particles and in general ionization of molecules in aqueous systems is determined by the proton-electron interaction in the dispersion medium and occurrence of electrostatic charge during Brownian motion of particles. Between the particles operate intermolecular forces of Van der Waals and forces of chemical bonds, that occur during chemical reaction.

The reason of all chemical interactions is predominantly a hydration shell, which is formed around the molecules of the dissolved substance  and colloido-dispersion particles. Especially intensive flow the chemical reactions at the phase boundary “hydrated particle - dispersion medium (water)”. On this interaction have an impact the various physical, physico-chemical and physico-mechanical impacts, especially low intensity (change the hydrodynamic regime of water movement, mechano-chemical and physical impacts, changes of temperature and pressure, electric and magnetic fields, ultraviolet and ionizing radiation, etc.). Especially strongly influence dissolved gases (in particular oxygen) and strong electrolytes.

Keywords: aqueous solution, electric charge, colloidal-dispersion system, theory of resistance.

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06.04.2016 at 7:10 pm