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Avrutin O. A.

The cause to which we are committed

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UDC 628.16.065.2

Akhmadieva Iu. I., Sazanova N. I.

Estimation of the efficiency of aluminum-containing coagulants
in low polluted surface water treatment through
the example of «Minskvodokanal» UE

Summary

«Minskvodokanal» UE has been continuously developing the technologies of water treatment with the purpose of improving drinking water quality and water supply services. One of the perspective directions of improving the technologies of surface water treatment at the Water Treatment Plant of Minsk is the search for new efficient chemicals, coagulants based on aluminium salts in particular. The data describing the quality of natural water incoming for treatment is presented. The process flow scheme of water treatment is presented. The issues of objective estimation of the efficiency of the chemicals studied are considered with obtaining consistent results proved under production conditions. The main controlled parameters of natural water and water after coagulant addition are determined, and the measurement techniques are presented. The experimentel results and technical process modeling under laboratory conditions is shown. A general program of laboratory tests of aluminum-containing coagulants has been compiled. The method of data processing and analysis with obtaining statistically consistent results has been developed. The periods of testing new coagulant brands that provide for taking account of the seasonal and annual fluctuations of the chemical and microbiological water components for selecting coagulants that are efficient throughout the year are denoted.

Key words

potable water , water treatment , coagulant , flocculator , low polluted water source

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UDC 628.35

Dubovik Ol’ga, Markevich R. M., Antonov K. V.

Improvement of biological removal of nitrogen and phosphorus compounds from wastewater under the conditions of cascade denitrification

Summary

In view of ever toughening requirements to wastewater treatment the optimization and intensification of wastewater treatment facilities operation become priority areas. The flow process scheme of wastewater biological treatment at the Minsk Wastewater Treatment Plant is represented by traditional aeration tanks and aeration tanks with organized cascade denitrification scheme. The main component of this scheme is the lack of inner recycle and possibility of dispersed inflow of clarified wastewater over the aeration tank zones. This provides for the presence of easily oxidizable organic substances in every anoxic zone. In view of building-up of pollutants in incoming wastewater and toughening the requirements to their removal the intensification of the biological stage has been an important aspect of the treatment facilities operation. The research objective was the scheme of cascade denitrification at the operating treatment facilities for the optimization of which different options of clarified wastewater distribution over the aeration tank zones were used. Wastewater entering the cascade denitrification is characterized by insufficient quantity of organic substances because a significant amount of industrial wastes. To increase the amount of organic substances it was decided to take out of service the primary settling tank and to reduce the frequency of sludge removal. The chosen optimal distribution of clarified wastewater over the aeration tank zones and increase of organic loading the efficiency of phosphate removal increased from 60 to 70%; and that of nitrogen removal – from 61 to 67%.

Key words

wastewater , biological treatment , nitrification , activated sludge , nutrients removal , cascade denitrification

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UDC 628.1.032

Chesnokova S. M., Savel'ev O. V.

Estimation of water quality in decentralized water supply sources of Vladimir

Summary

The effect of drinking water chlorination on its organoleptic properties posing a threat to the public health is considered. The water sanitary measurements, the compliance with the requirements to its physiologic adequacy, integral toxicity of the water in the decentralized water supply sources of Vladimir were studied. It was stated that water in all three investigated objects used by the population as alternative drinking water sources was physiologically adequate in relation to the concentration of macroelements and complied with the sanitary chemical requirements of SanPiN 2.1.4.1074-01. As for the concentration of microelements (fluorine and iodine) water in all the investigated objects was not physiologically adequate and did not meet the sanitary and hygienic requirements. The concentration of fluorine in the investigated sources of decentralized water supply and in drinking water of the Nerlinskii water intake varied from 0.1 to 0.3 mg/dm3 what was much less than the lowest limit of the physiologic adequacy and MPC. Iodine in the investigated sources was not detected. In some springs and wells of Vladimir nitrates were detected in concentrations much higher than the MPCs for drinking water. Water in two springs in Vladimir showed hypotoxicity for small crustaceans Daphnia magna Sr. what evidenced the presence in them of trace concentrations of toxic substances hazardous to health.

Key words

potable water , toxicity , physiological full value of water , decentralized water supply source , sanitary chemical indicators

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KOZLOV M. N.

Birth of the Moscow engineering and technology school
of wastewater treatment (part 1)

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UDC 620.197:628.132:691.32

Izmailov I. A., Rozovskaia T. A.

Repair and protection of concrete and reinforced concrete tanks in water supply and wastewater disposal systems

Summary

The basic mechanisms of the deterioration of concrete structures of treatment facilities in the process of operation are given. The methods of the structure rehabilitation and durability increase with the use of special repair and protection compositions are proposed. A particular problem during repair works is concrete salinity that is typical, e. g. for industrial sewers. The results of studying repair composition adhesion to saline concrete when using different methods of base preparation such as the use of polysilicate primer composition are presented. The given composition applied on the concrete surface provides for the significant improvement of the strength of the repair composition adhesion to concrete thereby ensuring the combined action of the materials in the repair zone. The main principles of selecting an efficient material system during rehabilitation works at different hydroengineering facilities are conside­red.
Combined use of Manogard PSM polysilicate impregnant and Starmex RM5 fast hardening non-shrinking repair composition provides for the combined action of the structure concrete and rehabilitated section as an entity owing to the high-strength adhesion equal to the cohesion strength of concrete itself. The use of Starmex Seal Flex polymer-cement composition as a method of secondary protection of concrete from corrosion provides for water-proof anti-abrasion coating resistant to acids and alkali dissolved in water.

Key words

reinforced concrete tank , adhesional strength , salinity , concrete repair , polysilicate composition , repair mortar , polymer-cement coating

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UDC 681.518

Kritskii G. G.

Urban utility infrastructure and digital technologies

Summary

Integration of all the trends of software development in the process of digital transformation will provide for establishing a uniform highly reliable urban IT environment. The use of digital technologies will result in the elimination of the negative impact of human factor on the operation of the utility systems. By the electronic model of the water supply and wastewater disposal systems the mathe­matical model of these systems is meant assigned to the city base map with account of the cadastral territorial divisions and designed for the imitation simulation of their operation modes. The structure of the utilities layer in the specialized geographic information system (GIS) is developed automatically with the formation of the layer objects and modes of their operation. The process of plotting utility networks on the city map has been automated to the uttermost. At that a topologically fixed network graph is developed with the bridging of the relative data bases to each object. It is advisable to incorporate the electronic model of the water supply and wastewater disposal systems into the uniform urban information system with a common base map, common address database with the separation of user access according to the operator profile. The rough estimate of the efficiency of introducing the software can be carried out by the expenditure estimates. Using the expenditure estimates the economic benefit will be calculated to some tolerance, however, it will provide for evaluating the benefits and necessity of purchasing the software.

Key words

geoinformation system , digital technologies , digital model , digital twin , utility network simulation , mobile devices , utility network calculation

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UDC 631.67:628.165

Kofman V. Ya.

The use of desalinated water for the needs of irrigation (review)

Summary

In quite a few foreign countries that suffer from water scarcity (Spain, Israel, Australia, Cyprus, OAE, Chile, China) and that are located in the regions with arid climate noticeable success has been reached or major developments in the field of using desalinated sea or underground water for irrigation have been initiated. The main technologies of water desalination for agricultural needs are reverse osmosis, ion exchange, electrodialysis. The factors that are constraining at this time large-scale deployment of desalinated water in irrigation practice include the high cost of desalination; the need of placing desalination plants close to agricultural fields; discharge of toxic concentrate from desalination process; the need of ensuring safety and remineralization of desalinated water. Quite a few research works in this field have been dedicated to the improvement of the energy efficiency of desalination, development of the improved irrigation schemes and selection of arable crops that could be irrigated with desalinated water with the highest economic benefit. Anyhow the steady increase of investments into the given field in foreign countries indicates that desalinated water can be definitely adapted for agricultural needs.

Key words

ground water , sea water , desalinated water , irrigation , remineralization , calcium , magnesium