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UDC 628.1.2:62-278
Frenkel V. S.
Membrane Technologies: Past, Present and Future (the North America as an Example)
SUMMARY
Basic tendencies in the field of development of membrane processes for water and wastewater treatment in the North America are covered. Main characteristics, basic trends and features of the use of membranes including membrane bioreactors are presented. Characteristics necessary for assessment and selection of the best membrane technologies for each certain project are compared. Membrane treatment has become the fastest growing sector in water treatment, wastewater treatment and water desalination. Four types of membranes are used according to membrane pore size: microfiltration (MF), ultrafiltration (UF), nanofiltration (NF) and reverse osmosis (RO). All four principal types of membrane guarantee the removal of the entire spectrum of water pollutants and can be used as a stand-alone technology for a majority of applications. Integrated membrane processes combining different membrane types are becoming a cutting edge approach to meet strict water/wastewater quality regulations because they allow the smallest possible system size, minimize chemical consumption, and provide the most cost-effective solution for the greatest number of applications.
Key words
potable water , wastewater treatment , reverse osmosis , ultrafiltration , desalination , membranes , microfiltration , nanofiltration , membrane bioreactor
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UDC 628.16
Ulchenko V. M., Tat’ianko Nataliia, Glinka Nikolai
Common problems at water treatment facilities and ways to address them
Summary
Due to the anthropogenic factors, the quality of surface water is subject to rapid, mainly negative, changes; therefore, water treatment plants not always can meet the standards of the drinking water quality. Currently, many water treatment facilities are in need of upgrade, re-technologization and even reconstruction. In addition, significant changes in the actual water supply by the water facilities (decreasing, as a rule) do not always produce a positive effect on the technical and economic indicators of the water treatment facilities. Problems arising during the operation of the water treatment facilities at all stages of surface water purification – microfiltration, chemical treatment, mixing with chemicals and flocculation, sedimentation, filtration and wash water treatment are summarized. The methods used by MY PROJECT JSC in its projects to address such problems as the lack of the treatment efficacy, overspending of chemicals, short filter cycle, large water losses for process needs, discharge of untreated wash water, high purification cost are considered.
Key words
sedimentation tank , microfiltration , rapid filter , mechanical mixing chamber , flocculation chamber , zeolites , reconstruction of water treatment facilities , dolomite
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UDC 628.16.067.1:66.081.63
Strelkov A. K., Baranov A. V., Tsabilev O. V., Efanov I. A.
Evaluating the efficiency of hollow fiber membrane use in wash water treatment
Summary
Urban development dictates the necessity of increasing the output of water treatment facilities which requires the maximum operation of all the pumping filtration stations. In this respect reusing treated wash water for utility and drinking purposes will provide for eliminating water shortage and reducing environmental pressure on water bodies. The task of increasing the capacity of pumping filtration station No. 2 in Samara is very urgent. River water purification is carried out following the single-stage scheme in contact clarifiers. In view of the specific features of the clarification process such scheme does not allow increasing the station capacity by optimization of filtering media selection. The use of baromembrane processes – microfiltration and ultrafiltration – can be an alternative that will provide for the sustainable parameters of the treatment quality. These methods find fairly wide use in river water treatment at small-scale facilities either as independent processes or as part of comprehensive process solutions. The process of wash water of pumping filtration station No. 2 purification that operated according to the single-stage flow scheme with the use of hollow fiber membrane was studied. The main trends and possibilities of retrofitting the new process flow scheme were considered. The results of preliminary testing a pilot unit on the basis of the hollow fiber membrane element are given. The evaluation of the received filtrate quality proves its possible use for utility and drinking purposes. The membrane unit concentrate in significantly less amount can be discharged to the wastewater treatment facilities or processed to separate and dewater the sludge.
Key words
water treatment , membrane , ultrafiltration , pumping-filtration station , microfiltration , wash water , pilot plant
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UDC 628.16:62-278
Vergunov A. I.
Removal of organic compounds from natural water
in a biosorption-membrane unit
Summary
The results of experimental studies on the purification of natural water of the Don River in a biosorption-membrane reactor equipped with flat-plate microfiltration membranes are presented. The research aimed at investigating the efficiency of the biosorption-membrane reactor operating with natural water with the subsequent determination of the kinetic characteristics of the running biosorption process. As a result of processing the experimental results, the efficiency of removing not only the turbidity and color of water, but also organic substances that caused high permanganate index and COD, was specified. The temperature constant was determined that provided for calculating the specific rate of oxidation of organic pollutants for the winter and summer seasons of the year. Using the obtained constants, it is possible to perform a design calculation of a biosorption-membrane reactor to any degree of purification required.
Key words
natural water , microfiltration , domestic water supply , biosorption membrane reactor , specific oxidation rate
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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 628.321
Gaid Kader, Sauvignet Philippe, Buisson Hervé
The combination Actiflo – MF/UF membrane: an efficient solution for surface waters
Summary
Process schemes of surface water treatment with membrane filtration in most cases at the final stage require advanced clarification technologies that provide for efficient removing color and high concentrations of organic and suspended solids from raw water. Therefore, «Actiflo® – ultra- and microfiltration» process scheme is the optimal solution for drinking water purification. The results of pilot tests of «Actiflo® – ultra- and microfiltration» process scheme are presented. The experience of operating the plants using this scheme is generalized.
Key words
coagulation , ultrafiltration , microfiltration , surface water , microsand , flocculation , pretreatment , Actiflo® process scheme
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UDC 628.16.081:628.191:576.8
DUDKIN E. V., Samsonova S. P.
Microfiltration removal of phyto- and zooplankton
Summary
The results of pilot testing DynaDisc microfiltration system manufactured by Nordik Water Produkts AB for capturing phyto- and zooplankton are presented. The tests were carried out at the treatment facilities of Volzhsky and Izhevsk water and wastewater companies by the experts from Ionoobmennye tekhnologee CJSC. The data on the efficiency of using microfiltration during water reservoir blossoming that results in reduced rapid filter loading and water quality improvement are presented.
Key words
turbidity , chromaticity , coagulant , flocculant , microfiltration , phytoplankton , filtration cycle , zooplankton
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