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Number 12 / 2025
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Literature lists to articles (doc)
Index of the Articles (pdf), Published in the Water Supply and Sanitary Technique Magazine in 2025г.
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UDC 628.16
DOI 10.35776/VST.2025.12.01
Gvozdev V. A., Borisov Sergei, Konstantinov Aleksandr, Buryka Elena, Portnova Tat’iana, Vitkovskaia Raisa, Nesterova Tatiana, Judin Vladislav
Providing for the efficiency of contact clarifiers under conditions of reduced design filtration rate
Summary
An analysis of methods of providing for the efficiency of contact clarifiers under conditions of reduced design filtration rates is presented. Under actual operating conditions of contact clarifiers with a lower than design capacity after the introduction of a coagulant (aluminum sulfate), the estimated residence time of the coagulant in the water is 5.3 minutes before contact filtration starts. Furthermore, the motion speed of the flow being two to three times lower than the design value, is approximately 0.02 m/s, which is typical for the floc formation conditions. As a result, an undesirable coagulation process occurs in the free volume, so that previously formed aluminum hydroxide flocs disperse to form colloidal aluminum hydroxide. The formation of colloidal aluminum hydroxide in the free volume under contact coagulation conditions may worsen rather than improve water purification processes; in particular, the rate of pressure loss in the granular filter bed may increase. The results of pilot tests at the Kolpino Water Treatment Plant operated by SUE «Vodokanal of St. Petersburg» are presented, followed by the introduction of the best technical solutions.
Key words
contact clarifier , contact coagulation , particle size distribution of the filter media , mixed chemicals
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UDC 628.164/.165
DOI 10.35776/VST.2025.12.02
Tcherkesov A. Yu., Shchukin S. A., Kaberskaia Dar’ia, Kniazeva Natal’ia, Zaichko Dmitrii, Shepelev Oleg
Results of studying chemical treatment of the nanofiltration unit concentrate
Summary
The results of industrial studies on chemical treatment of concentrate from a single-stage four-cascade nanofiltration unit are presented. The change in the cation-anion composition of the concentrate as a result of treatment with chemicals, including antiscalant. The studies of the chemical treatment of the fourth cascade nanofiltration concentrate by the lime-soda method conducted under industrial conditions showed the possibility of its effective application in principle. It has been experimentally confirmed that the introduction of an antiscalant upstream the nanofiltration units has a positive effect on the subsequent chemical treatment of the concentrate by the lime-soda method.
Key words
softening , desalination , domestic water supply , four-cascade nanofiltration unit , baromembrane separation of liquid
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UDC 620.1/.3
DOI 10.35776/VST.2025.12.03
Samburskii Georgii, Kagramanov Georgii
Some technological issues related to the implementation of «Clean Water» and «Volga Reclamation» Federal Projects
Summary
Some issues related to the implementation of the «Clean Water» and «Volga Reclamation» Federal Projects are considered. Was demonstrated that the quality of drinking water in public water supply systems and level of wastewater treatment not always meet the current requirements, notwithstanding that the water and wastewater treatment technologies have been chosen correctly. Vulnerable positions in the project implementation related to the lack of the risk-oriented approach to selecting technological solutions are also discussed. The objectives to be addressed in implementing the new «Water of Russia» Federal Project are outlined. The experience with project implementation in the Republic of Kazakhstan is presented that can serve as a benchmark for the further implementation of the «Water of Russia» Federal Project. Possible recycling of effluents is demonstrated.
Key words
water supply , water treatment , water disposal , membrane technology , risk-oriented approach
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UDC 502.1:537.312.53
DOI 10.35776/VST.2025.12.04
Karmanov Ruslan, Егорова М. Д.
Effect of ultra violet exposure on polymer fragmentation in aqueous media
Summary
Studying microplastics distribution in aqueous media requires understanding polymer fragmentation processes effected by the natural factors. It is widely accepted that UV radiation is the most important factor resulting in (relatively) rapid degradation of polymers: the solar radiation initiates autocatalytic thermal oxidation that is the trigger of polymer degradation in the environment. Wind and additional mechanical stress cause molecular chains to break, which, in the presence of oxygen, leads to increased plasticity of the material (so-called chemico-mechanical degradation). Mechanical fragmentation can also accelerate if the material already bears the traces of aging due to other destructive factors. As part of the study, laboratory experiments were conducted to accelerate the «aging» of polymers by exposing them to UV radiation on water surface at an intensity of 1.16 W/m2 until the first signs of fragmentation appeared on the polymer samples. Based on the obtained experimental data, the residence time of the target polymers – polyethylene (PE) and polypropylene (PP) – in the Izhevsk water bodies under the natural solar UV radiation conditions before the first signs of fragmentation appeared was calculated. The calculations show that while PE and PP entering the aqueous media being exposed to the natural UV radiation, the first signs of polymer fragmentation appear in 730 days in winter and 136 days in summer.
Key words
UV-irradiation , microplastic , plastic waste , polymers , degradation , fragmentation
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UDC 622.882:622.692.55
DOI 10.35776/VST.2025.12.05
Astashina Marina, Razumov Vladimir
Aspects of cleaning and reclamation of oil-contaminated sands of the temporary accumulation site of the Voskresenskii village in Anapa, Krasnodar Krai
Summary
The results of studying soil contamination by petroleum and oil products are presented. The studies were conducted by simple three-stage washing with the addition of surfactants, as well as screening of oil-contaminated sand to separate large fractions. A preliminary technology for the treatment and reclamation of oil-contaminated sand from a temporary accumulation site in the Voskresenskii village, Anapa, Krasnodar Krai, has been developed.
Key words
cleansing , sedimentation tank , oil products , sanitary protection zone , reclamation , fuel oil , surfactants
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UDC 628.35
DOI 10.35776/VST.2025.12.06
Kevbrina M. V., Danilovich Dmitrii, Shakhrai Nikolai
Recommendations on calculation while designing primary sludge acidifiers in order to enhance the processes of nitrogen and phosphorus removal from municipal wastewater
Summary
Recommendations together with calculation formulas for designing acidifiers of primary sludge in order to enhance biological removal of nitrogen and phosphorus compounds from municipal wastewater are presented. An example of calculations using the suggested formulas for the acidifiers at the Kur’ianovskie Wastewater Treatment Facilities in Moscow is given. The analysis of the acidifiers’ operation at the Moscow Wastewater Treatment Facilities testifies that under real conditions the main indicators such as solids (dry matter) retention time SRT, specific formation of BOD5 from ash-free sludge matter, and recycling of acidified sludge, correspond to the values calculated by the suggested formulas. The operational data validate the methodological approaches and calculation tools used in acidification plant design. The calculation formulas have been incorporated into the draft standard for calculating wastewater treatment facilities.
Key words
wastewater treatment , designing , acidification , readily available organic matter , prefermentation , acidoficator
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UDC 628.2:621.644.073
DOI 10.35776/VST.2025.12.07
Zakharov Iurii
Determining the wall thickness of flexible polymer liners
for the rehabilitation of III state class pipelines
Summary
Rehabilitation of damaged gravity sewer pipelines using flexible polymer liners, that utilize reactive resin systems as a binder, involves installing a new polymer pipe inside the existing pipeline. The wall thickness of the new pipe must ensure the static stability of the «new polymer pipe – pipeline being restored» system throughout the pipeline entire service life. An old pipeline of state class III is characterized by longitudinal cracks and significant deformations caused by the changes in soil parameters, as well as by the appearance of voids in the sealing area, so that it cannot independently support loads for an extended period. A method for estimating the static stability of a new polymer pipe-pipeline-soil system is presented with account of the properties of the sealing soil and pipeline ovalization. The main loads acting on a new polymer pipe during the rehabilitation of pipelines with longitudinal cracks (state class III) are determined. An algorithm for calculating the wall thickness of a flexible polymer liner for the rehabilitation of pipelines in this condition is proposed, depending on the applied loads. As an alternative to using special foreign programs for determining the wall thickness of a flexible polymer liner, a calculation method is proposed that provides for determining the liner wall thickness using tables and graphs while restoring a pipeline of state class III under the effect of soil pressure, groundwater, and traffic loads.
Key words
water disposal system , flexible polymer liner , static calculation , pipeline rehabilitation
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UDC 004.056:628.1
DOI 10.35776/VST.2025.12.08
Kiselev Aleksei, KINEBAS A. K., Sabirov Timur
An approach to constructing an adversary model as part
of the study of vulnerabilities in smart grid systems for water supply facilities
Summary
Smart Grid Water introduces a number of new, effective capabilities for the data collection, analysis, and information exchange to the water supply and wastewater disposal systems. However, it also adds vulnerability to the information security and, as a result, creates new threats and cyberattack vectors. The study focuses on modeling an attack scenario on a smart water supply system that exploits the vulnerabilities in the Modbus TCP industrial protocol. The results can be used for training professionals, for example, in a cyber range, for developing, implementing, and formally describing attack scenarios, for analyzing Modbus TCP vulnerabilities, and for testing the information security software. Practical recommendations for arranging the protection against cyberattacks are also offered.
Key words
Smart Grid Water , cyber attack , Modbus , Test-bed , Man-in-the-middle , Intrusion Detection System , Industrial Control System
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