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UDC 661.183.2

Mukhin V. M.

Activated carbon based on anthracite with high volumetric microporosity for water treatment

Summary

A new approach to the assessment of microporous structure and adsorption properties of activated carbon per unit volume has been substantiated. A few stage GAC technology for activated carbon production on the basis of anthracite has been developed. The qualitative characteristics of activated carbons made of anthracite from various regions of Russia have been studied and the affinity of their adsorption properties and strength characteristics is shown. The studies of adsorption properties of GAC (ground anthracite sorbent) activated carbon in drinking water treatment under static and dynamic conditions were carried out. The efficiency of activated carbon made of anthracite in removing heavy metal ions from wastewater from gold beneficiation plants is demonstrated. High adsorption capacity of GAC activated carbon both in relation to organic and inorganic pollutants in industrial water and wastewater treatment provides for its high efficiency in water supply and wastewater disposal systems. The study results showed that replacing sand or hydroanthracite media with active anthracite (eliminating the construction of a separate block with activated carbon) at the existing municipal water treatment facilities will provide for saving 150 billion rubles because the packed density of active anthracite is comparable to the packed density of quartz sand. Anthracite is not washed during filtration facilities backwash; with that both filtration of mechanical pollutants and sorption of molecular toxicants take place. As a result high quality drinking water is obtained without substantial expenditures.

Key words

anthracite , water treatment , activation , activated carbon , porous structure , adsorption properties

DOI 10.35776/VST.2022.01.05
UDC 628.336.3:544.723.21

Gorelaia Olesia, Romanovskii Valentin

Effect of the dose of the reducing agent on the properties
of magnetic sorbents from the deironing plant wastes

Summary

The results of the synthesis of sorbents prepared from the deironing plant wastes for the purification of oily wastewater using various doses of the reducing agent are presented. The reducing agent used was glycine, urea, citric acid, and hexamethylenetetramine with an «oxidizing agent – reducing agent» mole ratio equal to 1 (f = 1) and 3 (f = 3). The study and comparison of the properties of synthesized magnetic sorbents obtained at different initiation temperatures of an exothermic synthesis reaction with an «oxidizing agent – reducing agent» mole ratio equal to 1 (f = 1) and 3 (f = 3) were carried out: total static exchange capacity, specific surface area and oil capacity.

Key words

wastewater , water treatment , magnetic sorbent , wastes , доза восстановителя

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UDC 628.54

Sazonov D. V.

Influence of the pump type on the parameters of the pneumatic-hydraulic aeration system in flotation apparatus

Summary

Flotation has been one of the efficient water treatment technologies. Flotation treatment is based on small gas bubbles generated by different methods, pneumatic-hydraulic, in particular. A case is considered of air feeding before the pump and subsequent water-air mixture passing through the aerator, and air being broken to small bubbles. Possible operation in the presence of air determines the choice of self-priming pumps (centrifugal and vortex). Experiments were carried out on determining two of the most important aeration parameters: bubbling rate and average size of generated air bubbles that determine the efficiency of water flotation treatment. Based on the data obtained it is shown that in most cases centrifugal pumps have the advantages: considerable part of the air entering the pumps is dispersed at the outlet of the aerator to 30–100 μm bubbles; whereas in case a vortex pump is used air bubbles of more than 200 μm size are generated which is ineffective for water flotation. It is stated that for some wastewater types the use of vortex self-priming pumps can be more reasonable.

Key words

water treatment , centrifugal pump , aeration system , pneumatic-hydraulic flotation , aeration intensity , air bubble size

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UDC 628.161.3.001.891.53

Strelkov A. K., Egorova Yu. A., Bykova P. G.

Selection of most efficient chemicals for water treatment

Summary

The Saratovskoe water reservoir has been the main water source of the Samara public water supply. The municipal water treatment facilities have been built after typical projects and designed for clarification and disinfection of moderately polluted water. Lately sharp suspended solids reduction and organic pollution increase (mainly of natural origin) in the water source have been observed. During flood periods technogenic pollution (surfactants) is present, the concentration of manganese increases, phenol is found. At low water temperature, high color and permanganate value higher doses of chlorine and coagulant are required. Coagulation at low temperatures is inhibited which results in the concentration of residual aluminium and permanganate value exceeding the maximum permissible levels. Higher chlorine dosages cause higher concentrations of chloroorganics in water. Therefore a chemical for using during flood periods that will provide for the required quality of water shall be selected. The results of the laboratory studies of selecting the chemical type and optimum dosage for water purification from the Saratovskoe water reservoir during flood periods are presented. Eighteen coagulant trademarks manufactured by domestic and foreign producers were investigated. The optimum dosages of coagulant and flocculant were defined. From the coagulant samples presented two were selected that could provide for the maximum drinking water clarification at minimum levels of residual aluminium and permanganate value. The final choice can be made on the basis of the technical and economic calculations taking into account the chemical price, delivery cost and required water quality.

Key words

turbidity , sedimentation tank , chromaticity , coagulant , flocculant , filtration , water treatment , residual aluminium , permanganate oxidizability

DOI 10.35776/MNP.2019.12.08
UDC 628.16:62-278

Kofman V. Ya.

Gravity membrane filtration in water and wastewater treatment schemes (a review)

Summary

Gravity membrane filtration technology involves the use of flat polymer ultrafiltration and microfiltration membranes with pore sizes from several nanometers to several hundred nanometers submerged in water at 40-100 cm, i.e. operating under a hydrostatic head of 40–100 mbar as a driving force of the membrane filtration in deadlock mode. The bacterial community of the source water induces the formation of a biofilm layer on the membrane surface. At the same time, the presence of eukaryotes in the biofilm layer that are characterized by predatory behavior produces a kind of “biological purification” effect that provides for decreasing the filtration resistance of the biofilm due to the formation of voids and development of its heterogeneity. As a result of the dynamic development of such a system, its sustainability and relative continuity of the permeate flow at the level of 2–10 l/(m2·h) are achieved. Sustainable water flow in the gravity membrane filtration mode is maintained for many months without cleaning the membrane. The system ensures the removal of organic substances and pathogenic microorganisms from water. Different-scale testing of the gravity membrane filtration system has been carried out: for decentralized river water treatment, for stormwater and gray wastewater treatment in local treatment systems to produce water suitable for non-potable consumption, in wastewater treatment for safe discharge, and for seawater pretreatment before desalination. Currently, examples of the practical application of this filtration system are known.

Key words

ultrafiltration , water treatment , organic substances , pathogens , gravity membrane filtration , deadlock mode

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DOI 10.35776/MNP.2019.09.03
УДК 543.3:544.576

Vikulina Vera, Кирошка Стефания

Change in ζ-potential of aquatic environment in ultrasonic field

Summary

At the boundary of the adsorption layer of the micelle an electrokinetic potential arises named ζ-potential. The numerical value of ζ-potential produces a significant impact on the processes that occur during water treatment, namely, coagulation and sedimentation. The influence of ultrasonic cavitation on the change in ζ-potential of aquatic environment is considered. Ultrasonic equipment and instruments for determining ζ-potential are presented. Experimental data on the effect of ultrasonic field on the electrophoretic mobility of particles in water is presented. The dependence of ζ-potential on the duration of ultrasonic treatment is obtained. The conducted experimental studies confirm the use of the ultrasonic method of water treatment for the enhancement of water treatment processes.

Key words

water treatment , aquatic environment , ζ-potential , ultrasonic field

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UDC 628.196

Golovanchikov A. B., Yefremov M. Yu., Doulkina N. A.

Enhancing the removal of hardness and iron ions from water

Summary

The numerical calculation of the problem of determining the concentration of components in the flowing water and in the stationary solid state – ionite granules, is presented. For three cations, namely Ca⁺², Mg⁺² and Fe⁺² subject to removal, the reduced concentrations in ionite and equilibrium concentrations in the treated water are calculated for each component. The calculations made show more than double increase of the surface coefficient of external mass transfer and of the volumetric coefficient of mass transport when the electric field intensity changes from 0 to 100 V/m. With that, the cycle operating time increases due to the increase of ionite exchange capacity use.

Key words

iron , water treatment , ion exchange , hardness ions , cathode , anode , ionite , exchange capacity , electric field , mass transfer

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UDC 628.345.1.001.2

Getmantsev S. V., Gandurina L. V., Sychev A. V.

Research in Coagulation Properties of AQUA-AURAT™18and Aluminium Sulphate at Independent and Combined Application

Summary

Results of the experimental studies on coagulation of pollutants of various types (suspended substances, dyes and humic substances) with coagulant AQUA-AURAT™18 and aluminium sulphate at combined application depending on their ratio and order of insertion in comparison with composite coagulant AQUA-AURAT™105 are presented. It is shown, that the combined use of aluminium sulphate and AQUA-AURAT™18 at consecutive insertion or in the form of composition intensifies the process of water treatment for suspended and dissolved acid substances (humates and acid dyes) comparing with the independent use of coagulants at a lesser or equal dose. The composite coagulant AQUA-AURAT™105 is more efficient for removal of suspended substances from wastewater than dissolved organic pollutants of acid type.

Key words

suspended substances , coagulation , coagulant , water treatment , humic substances , dye

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UDC 628.345.1:544.77

Velyayev Yu. O., Mayorov D. V., Matveyev V. A.

Investigating the efficiency of using nepheline-based aluminosilicate coagulant

Summary

The results of investigating the efficiency of using aluminosilicate coagulant produced with the help of advanced technology of decomposing nepheline concentrate with 20–30% sulfuric acid are presented. The high efficiency of the produced chemical used for precipitating drill clay slicks, flotator discharge slurries and recycling water from apatite production; for removing copper, nickel, cobalt, fluorine, phosphorus and dissolved oil products from water is shown. The coagulant can be used for industrial and municipal wastewater treatment.

Key words

water treatment , aluminosilicate coagulant , nepheline , sulfuric acid

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UDC 628.166.094.3

Grabovskii P. A., Gorobchenko A. I.

Adaptive control method in water disinfection

Summary

Pathogenic microorganisms present in natural water sources can be partially removed in the process of physical and chemical treatment (coagulation, contact clarification, filtration with presedimentation or flotation and other methods). Their final inactivation can be provided by oxidation with chlorine, chlorine dioxide, sodium hypochlorite and chloramines, ozone, as well as by UV-irradiation. The problems arising during chemical water disinfection are considered. The actuality of the problems is related to the decrease in water consumption, in big cities in particular. Owing to this the time of water retention in the distribution network increases, and in the far points the concentration of disinfectants in water is unacceptably low. The complexity of determining the chemical dosages conditioned by continuous fluctuations in the water consumption and water quality is shown. The operation of a network with the use of EPANET 2.0 software was simulated. The disinfectant concentration changes in water along the network length for «short» and «long» sections were studied. The dosing patterns for a network with two disinfectant injection points were developed. The practicability of adaptive control of the disinfection process is shown and its algorithm has been developed. The introduction of the proposed control scheme will provide for not only economic benefit by reducing chemical consumption but also for improving the reliability of water disinfection, improving the quality of the disinfected water, developing the data base for optimization and predictions, improving the customer service level.

Key words

mobile laboratory , disinfection , optimization , water treatment , adaptive control , algorythm

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UDC 628.16.094.3

Kofman V. Ya.

New advanced oxidation technologies of water and wastewater treatment (part 1)
(foreign publications review)

Summary

With the increase in population and industrial water consumption satisfying the demand for drinking water becomes a very pressing issue. This problem can be solved by using innovation process flow schemes of wastewater treatment. Advanced oxidation technologies are among them, i. e. homogenous and heterogenous photocatalytic processes, ozonation, Fenton’s process options, ultrasonic treatment, wet oxidation, electrochemical processes, oxidation in supercritical
water, plasma processes, ferrate and persulfate technologies, ionization radiation and microwave treatment. Hydroxyl radicals play key role in these processes. Photocatalytic processes proceed in the presence of catalysts with titanium dioxide (TiO2) being most efficient among them. The processes proceed in photocatalytic reactors in the presence of suspended catalyst and supported catalyst. In the process of water disinfection the synergistic effect is reached at combining advanced oxidation technologies and chlorination. Fenton’s process is based on the use of Fenton’s reagent, i. e. mixture of Fe2+ salt (catalyst) and hydrogen peroxide. Optimal рН value of 2.8–4 is the basic parameter of this process. Ozonation process proceeding in the presence of hydroxyl radicals originating from chemical transformation of ozone at 2.8 hydroxyl radical reduction potential is considered. Optimal formation of hydroxyl radicals is provided in ozonizers with hydrogen peroxide dosing device (Peroxone process). Ozonation in the process of UV-irradiation; ozonation in the process of UV-irradiation in the presence of hydrogen peroxide, ozonation in combination with ultrasound (Sonozone process) are considered. The use of advanced oxidation technologies in wastewater treatment produces positive results that provide for satisfying the water demand. (To be continued).

Key words

chlorination , ozonization , water treatment , catalyst , oxidation technology , hydroxyl radicals

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UDC 628.33

Alekseyev E. V.

On using «specific flotosorption» index in flotator process design

Summary

An approach to describing the process of extracting pollutants by flotation based on the adsorption mechanism of the interaction of the participating phases is suggested. Basing on these perceptions possible determination of the flotation engineering parameters is shown. The analysis of the typical dynamics of the water treatment process in contact flotation cell models is presented. The recommendations on determining the parameters of the flotation process: flotation cell capacity and supplied gas (air) flow rate are given.

Key words

flotation , adsorption , water treatment , Langmuir isotherm , specific flotosorption

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UDC 628.16.081:661(24+48+63)

Gandurina L. V., Potapova L. V.

Precipitating capacity of AQUA-AURAT™30 coagulant in water treatment in the presence of calcium hydroxide

Summary

The results of experimental studies of simultaneous elimination of sulphates, phosphates and fluorides from water with AQUA-AURAT™30 aluminium polyoxychloride in the presence of calcium hydroxide are presented. It was shown that the standard concentration of sulphates and phosphates is ensured with the chemical dosage ratio 4.5 (as active СаО/Аl₂О₃) and рН 11. Fluoride concentration under the circumstances is decreasing from 11 to 2 mg/l. The standard fluoride concentration in treated water is ensured at рН 7.

Key words

coagulant , water treatment , phosphates , aluminium polyoxychloride , calcium hydroxide , sulphates , fluorides

DOI 10.35776/MNP.2020.01.02
UDC 628.1:006.3:66-926

Samburski Georgi, Ustinova O. V., Leont’eva S. V.

Specific features of standardization of chemicals
for the preparation of drinking water (through the example of polyaluminium chloride coagulant)

Summary

Coagulation process has been a widespread process technology for removing coarse suspended impurities from water, as well as colloidal organic contaminants present in dissolved form. Polyvalent metal salts are effective coagulants for the systems with aqueous disperse medium. The purpose of the work was developing a new state standard to provide for a uniform assessment of the quality of coagulants. The scope of coagulants in the process of water treatment is considered and their comparative analysis is carried out. The general requirements to the control of polyaluminium chloride quality are formulated. The developed and approved new national standard GOST R 58580-2019 «Polyaluminium chloride. Technical conditions» is presented that takes into account the requirements of sanitary legislation, technical regulation, safety of the processes of production and transportation of polyaluminium chloride.

Key words

water treatment , water treatment , aluminium polyoxychloride , coagulants , standardization of chemicals

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UDC 628.161.2:614.777:546.47/.49

Larionov S. Iu., Panteleev Aleksei, Riabchikov Boris, Shilov Mikhail, Kasatochkin A. S.

Removal of natural radionuclides from underground water sources

Summary

Natural radionuclides are present in underground water sources of some Russian regions in the concentrations exceeding the maximum permissible level for drinking water. Natural water radioactivity is caused by the presence of uranium 238U and thorium 232Th isotope decay products including radium and radon. For the purification of radium containing water lime softening, sorption on special adsorbents (e. g. zeolites), ion exchange softening and active aluminium oxide or active alumina, manganese containing media are used. The given methods of treatment are described in a number of publications that state the possible use of reverse osmosis or nanofiltration, however, lack the information on their application. Membrane technologies in combination with the traditional methods allow designing the flow scheme of radionuclides removal from underground water. During the tests on producing water of the required quality for an open-cycle heat supply system no radionuclides accumulation was observed. For the operation period (1.5 month) of the ultrafiltration plant during the interval between backwash cycles the radiation background straight at the membrane increased insignificantly; whereas, after the backwash it returned to the initial level. Backwash number was more than 100 providing for the statistically valid data. The reverse osmosis plant was operating with ultrafiltration permeate. The total radionuclides in the parent solution was about 1.4 Bq/l, in reverse osmosis filtrate – 0.005 Bq/l, i. e. much lower than the maximum permissible level. In reverse osmosis concentrate this value does not exceed 1 Bq; therefore, it can be discharged into the open hydraulic networks in compliance with the established standards. No activity accumulation on the reverse osmosis membranes was observed.

Key words

aeration , reverse osmosis , ultrafiltration , nanofiltration , membrane technology , water treatment , radionuclides , radioactive wastes

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UDC 628.35:62-278

Pervov A. G., Matveyev N. A., Karasyev P. L., Motovilova N. B.

Removing oil products and detergents from surface runoff with the use of reverse osmosis systems

Summary

The studies of developing advanced technologies of surface runoff treatment from oil products and detergents are presented. The technologies are based on the process of reverse osmosis with the use of membrane units of a new type with an «open channel». Eliminating the causes of deposit formation can provide for ten-fold increase of the incoming water concentration in the units. The amount of concentrate (aqueous solution containing concentrated pollutants) is reduced to less than 1% of the initial water amount. With such small amount the concentrate is removed together with sludge. The estimations of the economic benefit of the rational utilization of surface runoff for technical purposes are presented.

Key words

suspended substances , oil products , reverse osmosis , surface runoff , water treatment , membrane unit , concentration factor

UDC 628.16
DOI 10.35776/VST.2023.04.02

Aleksandrov Roman, Kagramanov Georgii, Laguntsov Nikolai

Developing a unit for water pretreatment for the hybrid chemical-membrane purification system

Summary

At the present day developing and upgrading the methods for water pretreatment in membrane purification plants is a relevant objective. The purpose of this work has been the development and study of a small-sized water pretreatment unit based on the chemical method for the purification of heavily polluted water with high efficiency in terms of the degree of purification, chemical and energy consumption. A water pretreatment unit based on a dosing and mixing device for chemicals including jet hydrodynamic mixers – ejectors, has been developed. The device allows dosing chemical solutions in a wide range of injection coefficients and provides for improving the removal of hardness salts and heavy metals by more than 20%, and of oil products – by 8% compared to standard mixing with a blade mixer (120 rpm) owing to the mass transfer proceeding in an intense hydrodynamic field at Re >> Recr. Hybrid alumosilicic chemical was developed and studied that provided for reducing the concentration of toxic residual aluminum in purified water by an order of magnitude more (up to 0.02–0.05 mg/l) in comparison with other aluminum-containing reagents owing to the formation of mesoporous alumosilicic structures possessing the effect of volumetric sorption in 6–8 pH range. An experimental model of a portable water treatment plant with a unit of chemical pretreatment and membrane post-treatment based on the microfiltration technology using a porous titanium carbide membrane and low-pressure reverse osmosis technology with the use of a membrane made of a thin-film polyamide composite has been designed. It is shown that using a pretreatment unit provides for increasing the performance of the microfiltration device up to 3.7 times while removing oil products and hardness salts from water, and up to 4.3 times while removing heavy metals (copper). It is also shown that the developed version of the portable plant provides for a preset degree removing the main pollutants from heavily polluted wastewater in at the lowest specific energy consumption of 2.57 kWh/m³ compared to the analogues.

Key words

mobile plant , reagent treatment , microfiltration , water treatment , hybrid system , pretreatment , membrane methods , low-pressure reverse osmosis

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UDC 628.16.065.2

Getmantsev S. V., Gandurina L. V., Sychev A. V.

Comparison of aluminium-containing coagulant efficiency in turbid river water purification

Summary

The results of comparing the efficiency of inorganic aluminium-containing coagulants with different chemical composition and basic substance concentration when used for turbid river water purification: aluminium sulphate, AQUA-AURAT™ aluminium polyoxychlorides as well as composite aluminium-based coagulants are presented. It was shown that composite coagulants and coagulating-flocculating compounds are most efficient for turbid water treatment.

Key words

turbidity , coagulant , flocculant , water treatment