DOI 10.35776/VST.2023.04.01

Pavlinova I. I., Orlov Evgenii, Shipkov Oleg, Sinianskii Ivan, Shelaputina Nataliia

S. V. Iakovlev and NII VODGEO: years of fruitful work

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

UDC 628.11/.12:658.26:004.02
DOI 10.35776/VST.2023.04.03

Baranchikova N. I., Yepifanov S. P., Dytte A.

Hydraulic calculation of group water intakes on underground wells equipped with pumps with variable speed drives

Summary

The use of variable speed drives at group water intakes on underground sources in water supply systems is aimed at saving electricity, ensuring efficient operation modes, improving the management engineering; however, without sufficient justification the desired result is not always effected. One of the reasons is the lack of calculation using an effective mathematical model that describes the movement of water in aquifers, wells, lift pipes and gathering mains, taking into account all the existing limitations, including the mode parameters while using variable speed drives in some or in all submersible pumps. The model is submitted in the form of an optimization task where the target function is the total power input of all the operating submersible pumps. The proposed optimization model provides for describing the modes of the group water intakes operating from the intake external boundary to the tanks. All the limitations of the optimization task can be divided into three non-overlapping groups as follows: balance, technologic, and performance ones. Having calculated the electricity consumption for all significant modes during the year and compared them with the costs at the existing modes without variable speed drives, we can make a reasonable conclusion about the applicability of a variable speed drive in one or more submersible pumps. The proposed model provides for arranging both efficient and technologically allowable operating modes.

Key words

frequency converter , water well , aquifer , submersible pump , hydraulic head , flow distribution task , optimization task , energy input , group water intake

UDC 628.28
DOI 10.35776/VST.2023.04.04

Maslov Andrei

Reliable sealing cushions for big sewers

Summary

One of the most important measures for the successful repair works is the reliable blocking of the pipeline for the repair period. The use of LAMPE pneumatic sealing cushions for this purpose in large-diameter sewer networks has shown their high efficiency. LAMPE sealing cushions are fundamentally different from rubber plugs by the material they are made of and by the technologies of their manufacture. As a result, they are lighter, easily pass through a conventional hatch, do not require additional blocking, they are maintainable, and have an unlimited service life. All of these advantages make it possible to quickly and reliably cut off the failed section of the pipeline for the period of repair works and, having ensured their absolute safety, significantly reduce the time for eliminating the failure.
аварии.

Key words

pipeline , sewerage network , LAMPE pneumatic sealing cushion , LAMPE pneumatic lift

UDC 628.212.2
DOI 10.35776/VST.2023.04.05

Grekov Mikhail, Elagin Sergei, Kozinets Galina, Chechevichkin Viktor, Leonov L. V., Klokov Aleksandr, Chechevichkin A. V., Iakunin L. A.

Experience of all-season use of FOPS®-K filter to remove debris from the surface runoff of a residential area

Summary

In residential areas that are places of residence and various activities of the population, a significant amount of solid materials of various origin and dispersion is formed that can be defined as debris (or municipal sweepings for roads). While interacting with atmospheric precipitation, this debris enters public wastewater disposal systems disrupting their operation («Rules for cold water supply and wastewater disposal»). To solve this problem, experimental studies were carried out to estimate possible removing debris from surface runoff using a FOPS^®-K filter (basket type). The premises of the university campus was chosen as an experimental residential area where debris of biological, anthropogenic and technogenic origin accumulated. The results of testing FOPS^®-K filter for two cycles (each for 12 months) showed that using the filter provided for removing not only large debris but also a significant part of the sand (3/4 of the total dry matter) from the surface runoff up to the size except 0.04 mm. It was established that all components of the debris captured by the filter contained 3–66.3 g/kg of oil products. During the tests, the debris was regularly removed from FOPS^®-K filter (once every 3 months).

Key words

surface runoff , residential area , FOPS filter , debris removal

UDC 628.381:006.3:349.6
DOI 10.35776/VST.2023.04.06

Samburski Georgi, Shkaredo Viktoriia, Epstein Aleksandr, Maksimova Angelina

Wastewater sludge: secondary raw materials or by-products?

Summary

The issues of developing statutory regulation for wastewater sludge treatment are analyzed. Recommendations are given for water supply and wastewater disposal providers on classifying treated wastewater sludge as a by-product or a secondary resource. It is noted that the transition to a circular economy announced by the Ministry of Natural Resources of Russia involves the development of a regulatory framework; however, the passport of the federal project «Circular Economy» and presentation materials of the Ministry of Economic Development of the Russian Federation and the public-law company «Russian Ecological Operator» reduce the issues of the circular economy exclusively to the tasks in waste management, which carries high risks of significant costs associated with referring wastewater sludge to wastes. The introduction of new, statutory formalized concepts of «secondary raw materials» and «by-products of production» should play a decisive role in developing the regulation of wastewater sludge handling processes and using it in the economic activities as goods.

Key words

wastewater sludges , circular economy , secondary raw material , by-product of production

UDC 628.221
DOI 10.35776/VST.2023.04.07

Volkov Sergei, Luk’ianchuk Maksim, Zhitenev A. I., Kuz’min Valentin, Rublevskaya O. N., Gvozdev V. A., Erofeev Vasilii, Kostenko I. G., IGNATCHIK V. S., Ignatchik S. Iu., Kuznetsova N. V., Seniukovich Mikhail

Methods and results of estimating calculated rain parameters for the surface runoff disposal systems of Saint-Petersburg Part 2. For hydraulic calculations in simulation

Summary

Urban surface runoff disposal systems need to be adapted to the changing climate with account of local conditions and schematic design features. In line with the world practice, one of the stages of the works in this area is the substantiation of the calculated parameters of rain for the considered climatic region. At the same time, to fulfill the design tasks adjusting the specified climatic parameters will be sufficient. However, justifying the solutions on the upgrade of the drainage systems using computational models, substantiating the profiles of calculated rains constituting the graphs of the temporal variations of their intensity is needed. While substantiating these profiles, the following requirements were taken into account: the maximum 10-minute amount of precipitation that can cause flooding in the wastewater disposal networks; the accumulative amount of atmospheric precipitation during 1 hour that can cause flooding in the tunnel sewers. It has been established that under these requirements, the temporal variation of the rain intensity representing the design rain profile can be expressed as a continuous analytical function with two parameters: i₀ – the maximum instantaneous rain intensity (mm/h) and the empirical parameter φ (min^–1). It has been experimentally determined that for St. Petersburg, for example, with a return period of p = 1 year, φ = 0.1837 min^–1, i₀ = 40.21924 mm/h.

Ключевые слова

surface runoff disposal systems , flooding , adaptation measures , calculated parameters of rains , rain profiles