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UDC 628.16:62-278

Kuznetsov V. N.

Return of filter washings and sludge treatment  at the Western Filtration Plant of Ekaterinburg

Summary

In order to abandon discharging polluted filter washings into the water source a system of filter washings treatment in ultrafiltration membranes for reusing was developed alongside with a unit for the treatment of sludge generated at the filtration facilities. The method of ultrafiltration is at the heart of the filter washings treatment technology. Filter washings from the main process line are filtered through special membranes that provide for the separation into clean water (permeate) and concentrate (sludge). The sludge from horizontal clarifiers of the main process line and the sludge from the ultrafiltration unit are removed to the sludge treatment facilities. Precipitated sludge with a moisture content of 98.5% is removed by the scraper system into the sump whereof it is transported further to the belt thickener and then into the chamber filter press. Dewatered sludge with a moisture content of 75% is transported by trucks to the solid waste landfills. The implementation of these innovations provided for the significant reduction of water amount used for own needs; thus, the total water losses do not exceed 1.5%; water abstraction from the water source was also reduced as well as the water supply deficit. The results of the first several months of the ultrafiltration facilities operation showed that the quality of the treated drinking water met the requirements of the sanitary regulation and standards.

Key words

ultrafiltration , filter washings reuse , sludge treatment , water supply deficit

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/VST.2021.01.01
UDC 628.167.069.84

Tcherkesov A. Yu., Shchukin S. A., Denisova Irina

Study of the catalytic iron oxidation of hydrogen sulfide by air oxygen in a reactor with a membrane separator

Summary

The results of studies of the catalytic iron oxidation of hydrogen sulfide by air oxygen in a reactor with a membrane separator are presented. The studies were carried out in a laboratory setup. An artificially prepared model hydrogen sulfide-containing water served as the object of study. The laboratory setup was a reactor vessel where hydrogen sulfide was oxidized by air oxygen in the presence of iron hydroxide that acted as a catalyst for the process. The separation of purified water and Fe (OH)₃ was carried out by ultrafiltration. All the experiments were executed under the conditions recommended for the iron catalytic oxidation of hydrogen sulfide: concentration of iron (III) hydroxide 2 g/dm₃, pH 7–8, residence time in the reactor 1 hour, air consumption 2 m³/m³, temperature 20–23 ºС. The oxidizing ability of the method has been experimentally confirmed at the above standard values of the indicators. A regression equation has been obtained that describes the catalytic oxidation of hydrogen sulfide by air oxygen in a reactor with a membrane separator. The presented method can be recommended in the process flow schemes of natural hydrogen sulfide-containing water purification for the purposes of drinking water supply.

Key words

ultrafiltration , sulfide-alkaline wastewater , hydrogen sulfide , membrane separation , air oxygen , iron hydroxide

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UDC 628.35:648.1

Försterling Ch., Fähnrich A., Crawford Daniel, Kühne Lothar, Barjenbruch Matthias

Wastewater recycling in small laundries using MBR-technology

Аннотация

The operation of laundries in Germany is characterized by high water and energy consumption. The business competition, increase of energy cost and active legislative requirements provide for growing demand for wastewater reuse systems (for process water treatment, heat and chemical recovery). In relation to the washing technology the level of water saving is rather high. However, the consumption of fresh water cannot be reduced unless the technologies of wastewater treatment and reuse have been integrated into the existing system. There are few if any examples of using wastewater reuse technologies for small laundries with a capacity of less than 500 kg/day; whe­reas the available water recycle systems are not efficient enough. A membrane bioreactor with flat submerged ultrafiltration membranes was installed at one of such laundries. The operation of the bioreactor provided for 93% COD reduction, and 90% water return. The quality of permeate was very high (it did not contain suspended solids or microbes) and met the requirements to the reuse in washing process. The cost analysis showed that the use of available permeate heat instead of electrical energy improved the economic efficiency of the laundry operation.

Ключевые слова

ultrafiltration , heat utilization , membrane bioreactor , laundry wastewater , water recycling , industrial wastewater treatment

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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 628.1.03

Ponomarev A. P., Podkolzin I. V.

Morphology and mineral composition of nanostructures
in drinking water

Summary

As a result of the studies the method of excreting nanostructures from drinking water samples on the basis of micro- and ultrafiltration with the use of microfilters (450 nm pore size) and semipermeable membrane (15 nm pore size) was developed. It was found that in the process of ultrafiltration the mineral composition of water before and after passing through the membrane did not change. At the complete water passing into ultrafiltrate the membrane traps organomineral nanostructures with a diameter of 10–200 nm containing macro- and microelements. The integrated method of micro- and ultrafiltration provides for the efficient removal of nanostructure or nanobacteria from drinking water while preserving its mineral composition; this allows recommending this method for obtaining purified water for humans and animals. The analysis of the nanostructure mineral composition showed that calcium and sodium were prevailing macroelements; their total respective percentage content was 60–70%. This data proves the prior information given by the authors that calcium has been the main building blocks of the nanobacteria coat identified in human and animal blood. Taking into account the morphological specific features of the nanostructures excreted from drinking water, their form and dimensions, it should be noted that they are identical to the transformed cells of nanobacteria of human and animal blood. Comparison of the results of the analyses of three independent methods – electron microscopy, mass-spectrometry and chromatography allows being reinforced in view that nanobacteria originate from water that brings them into living organisms. Herewith, research workers that deny the existence of nanobacteria as living organisms recognize the fact that the given nanostructures can produce a significant impact on the human health.

Ключевые слова

potable water , ultrafiltration , nanostructures , electron microscopy , mass-spectrometry , liquid chromatography

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UDC 628.165:66.081.63

Kurdiumov V. R., Timofeev K. L., Kraiukhin S. A.

Specific features of using reverse osmosis for mine water treatment

Summary

The possibility of using reverse osmosis for treatment of mine water from dead copper-nickel pits was studied. The composition of mine water was, mg/dm³: Mn 0,6–1; Fe 0,01–0,1; Ni 0,8–1,5; Cu 0,3–0,5; Zn 0,05–0,25; Co 0,02–0,07; Na 35–50; Ca 125–150;
Mg 35–45; SO4 100–200; Cl 65–75; Al 0,02–0,05; Si 9–11; Se 0,1–0,2; As < 0,005; Te < 0,005; Pb < 0,005; Hg < 0,00005; salt content 750–850; total hardness 9.5–11.5 °dGH; рН 7–7.5. The studies were carried out in a pilot plant with a capacity of 1 m³/h with original mine water. The plant included ultrafiltration and reverse osmosis modules. The permeate yield varied in the range of 50–75% of the original water volume. The method of chemical mine water demanganation and de-ironing at the primary treatment stage was tested. The quality of effluent (permeate) fully conforms to the drinking water requirements. The operating conditions of the pilot plant are described; the chemical unit consumption is presented. The specific features of using reverse osmosis technology for mine water treatment are described. The basic performance indicators of the reverse osmosis unit in terms of the equivalent amount of 1 m³/h at
the effluent output of 75% of the inflow are presented. The method of concentrate utilization is described providing its yield is reduced to 5% which makes it possible to extract valuable admixtures (non-ferrous metals).

Key words

deferrization , reverse osmosis , ultrafiltration , stability index , demanganization , concentrate utilization , mine water , non-ferrous metals

DOI 10.35776/VST.2022.03.07
UDC 628.316:66.081.63

Il’ina Marina, Selivanov Oleg, Pikalov Evgenii

Estimation of the ultrafiltration efficiency for leachate treatment from solid waste landfills

Summary

The results of estimating the efficiency of wastewater treatment by ultrafiltration in various membrane elements upstream reverse osmosis separation are presented. The studies were carried out in a pilot ultrafiltration unit using ceramic tubular membrane elements and hollow fiber membrane elements made of polysulfone and polyvinylidene fluoride supplied by various manufacturers. Leachate of a solid waste landfill was used as the test water. The research results showed that all the considered membrane elements provided for a high degree of removing suspended solids (> 99.9%), total iron (80%), oil products (> 90%), non-ionic surfactants (> 84%). The final performance of all tested membrane elements was virtually the same. Comparing the performance of membrane elements with clean tap water after chemical washing showed that the highest degree of recovery was observed in a pressure hollow fiber element based on polysulfone (80%). Thus, hollow fiber membrane elements made of polysulfone will have the longest service life while maintaining a high degree of purification of leachate from a solid waste landfill.

Key words

wastewater treatment , ultrafiltration , ceramic membrane element , hollow fiber membrane element , specific filtration rate

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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 628.161.2:614.777:546.47/.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 628.349.087.4:621.357

Pavlov D. V., Kolesnikov V. A.

Electroplating industry wastewater treatment: advanced solutions

Summary

An innovative technology of electroplating industry wastewater treatment on the basis of electroflotation and ultrafiltration combination has been developed. From technical and economic point of view this technology provides for removing heavy metals from wastewater to 0.01 mg/l, SS and oil products to 0.05 mg/l at relatively low wastewater treatment facilities operational expenditures. The electroflotation plant and unltrafiltration unit on the basis of tubular ceramic membranes are recommended for introduction at the industrial wastewater treatment facilities that are either subject to upgrade or under construction. The main task of the technology and equipment designers is the reduction of the treatment facilities construction and operation expenses while maintaining the high quality of treatment.

Key words

wastewater treatment , ultrafiltration , heavy metals , ceramic membrane , electroflotation

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UDC 628.16:62-278

Pervov A. G., Andrianov A. P., Gorbunova T. P.

Development of Membrane Techniques with Reduced Water Consumption for Own Needs

Summary

Issues of the improvement of membrane techniques used in water treatment for the reduction of consumption of a concentrate at reverse osmosis plants and wash water at ultrafiltration units are considered. A change in the design of the membrane canal makes it possible to eliminate the causes of formation of sediment’s crystals. New techniques of water treatment with utilization of the concentrate and reduction of water consumption for own needs are proposed.

Key words:

filtrate , water treatment , concentrate , membrane , reverse osmosis , ultrafiltration

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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