Stepanov Mikhail

Задачи армии решаем силами батальона

Аннотация

Недаром говорят, что как корабль назовешь, так он и поплывет. История АО «Инжпроектсервис» началась в далеком 2001 г. в Москве на Фрунзенской набережной. У парапета на волнах Москвы-реки качался дебаркадер, на борту которого был бар с грозным названием «Причал торпедных катеров», по соседству с ним и располагалась наша компания. Как знать, но, возможно, это соседство и определило ее судьбу.
Первые годы своего плавания в бушующих волнах строительного комплекса Москвы небольшой коллектив проектировщиков занимался проектами сетей для подключения отдельно стоящих зданий и АЗС.

Ключевые слова

DOI 10.35776/VST.2021.10.01
UDC 628.2:62-192

Stepanov Mikhail, Primin Oleg

Problems of the reliability of water supply and wastewater disposal systems, and ways of solution

Summary

Reliability and environmental safety are the main requirements for water supply and wastewater disposal systems. Pipeline systems are an integral part of the infrastructure of modern cities. Malfunctions of these systems are mainly associated with failures in pipeline sections, that are the most functionally significant, expensive and vulnerable elements of the systems. The increasing rates of wear and unsatisfactory technical condition of a significant number of water pipelines and sewers in most cities and communities of Russia, the limited material resources for their rehabilitation and renovation in the context of reforming the housing services and public utilities of Russia require a scientifically based approach to solving the problem of assessing and ensuring their reliability. It is noted that up to now, in domestic practice, the accumulation and use of statistics for determining the reliability indicators of the elements of water supply and wastewater disposal systems, as well as planning their rehabilitation, have been arranged unsatisfactorily. Methods for assessing the reliability of pipelines, a methodology for planning their rehabilitation using a software application, criteria for selecting objects for pipeline renovation and ways to improve their reliability are presented.

Key words

pipeline , ecological safety , reliability indices , methodology for rehabilitation planning

DOI 10.35776/VST.2021.10.02
UDC 628.166:541.135

Pchel'nikov I. V., Nguen Tkhi Tuan Z’ep, FESENKO L. N.

Study of the current waveform effect on the formation of cathode deposits during direct electrolysis.
Part 1. Electrolysis of fresh water

Summary

During the electrochemical processing of chloride-containing natural water in a membraneless electrolyzer, salts of hypochlorous acid are formed that are exhibiting oxidizing properties. This process is widely used for the production of sodium hypochlorite disinfectants. The raw material for the production of sodium hypochlorite can be not only artificially prepared saline solutions, but also natural mineral water containing chlorides. The electrolysis of such solutions results in the formation of insoluble calcium and magnesium salts at the cathode of the electrolyzer thus inhibiting mass transfer in the interelectrode space and the occurrence of emergency situations. The first part of the article presents the results of studies of direct electrolysis of fresh water with constant and reverse current in Dong Hoi city, Republic of Vietnam. In the conducted tests the effect of reverse current in comparison with direct current on the reduction of the formation of insoluble substances at the cathodes of the electrolyzer was determined. The experiments have shown the advantage of reverse current over direct current. So, during the electrolysis with reverse current for a period of up to 6 hours, the amount of deposits on the electrodes did not increase, however, with direct current the deposits accumulated from the very beginning of the electrolysis process. This is due to the fact that the precipitate formed during the cathodic half cycle is dissolved during the anodic half cycle by acid, a product of water oxidation. The current output of chlorine for tap water was no more than 23% with a current density of 100 A/m².

Key words

disinfection , water treatment , sodium hypochlorite , direct electrolysis with constant and reverse current , fresh water

DOI 10.35776/VST.2021.10.03
UDC 628.35:615.076

Dubovik Ol’ga, Markevich R. M., Gavrilovich Ekaterina, Grebenchikova Irina, Ivanovich Vadim

Improving the hydrobiological analysis of activated sludge
at the Minsk wastewater treatment facilities

Summary

Based on the accumulated experience in operating the Minsk Wastewater Treatment Facilities and a review of information sources, a scheme for the hydrobiological analysis of activated sludge was determined, and a form for recording the results of the analysis was provided. For the quantitative account of filamentous microorganisms, an original five-point system was developed. Based on the literature data analysis, favorable conditions for the mass growth of filamentous microorganisms found in activated sludge were determined. Over a long period of time, including different seasons of the year, the improved methodology was tested for monitoring the state of the sludge suspension at two sites of the treatment facilities: traditional four-line continuous-flow aeration tanks at the first site and bioreactors with cascade denitrification at the second site. The species of filamentous microorganisms, permanently living in wastewater treatment structures, have been identified, and the dominant species have been determined. The results of the analysis of filamentous forms and sedimentation characteristics of activated sludge are compared. Conclusions were made about the features of the biocenosis in the aeration tanks at the first site and in the bioreactors at the second site; about the identity of the species composition of the filamentous bacteria communities, the effect of the wastewater composition and treatment conditions (sludge load, occurrence of zones with different levels of aeration) on the properties of the sludge suspension.

Key words

wastewater treatment , sludge index , activated sludge , active sludge dosage , hydrobiological analysis , filamentous form of microorganisms , point-based system

DOI 10.35776/VST.2021.10.04
UDC 628.336.7

Markelov Aleksei, Shiriaevskii Valerii, Krivoborodov Iurii, Sheremeta Ignat, Nikitin Vasilii

Test results of a pilot plant for vitrification of sludge

Summary

Ekopromtekh R&D Center, LLC (a resident of the Skolkovo Innovation Center, a member of the Moscow Innovation Cluster) has developed an innovative solution to the problem of utilization of sludge generated during wastewater treatment – the sludge vitrification technology. To prove the working efficiency of the technology, its technical feasibility; to determine the environmental indicators and energy characteristics a pilot plant was designed at the existing Shchelkovo interdistrict wastewater treatment facilities with the support of the Skolkovo Foundation in the Moscow Region. In the process of operating the unit, a number of positive effects of the introduction of the technology were revealed. It is shown that vitrification of wastewater sludge rovides for reducing the volume of waste by 25 times (in relation to pre-dewatered sludge), obtaining a safe vitrified material at the outlet for use in construction. To determine the energy characteristics of the process, an integrated experimental-theoretical approach was used including the comparison of the measurement results with the data obtained in the course of CFD modeling and thermophysical calculations. The environmental safety has been confirmed according to the program developed by NII Atmosfera JSC, the measurements were carried out by the Center for Laboratory Analysis and Technical Measurements of the Central Federal District. During the tests, it was proved that, in contrast to incineration, hazardous emissions of superecotoxicants (dioxins/furans) were completely excluded. The measurements were carried out by the Laboratory of Analytical Ecotoxicology of the Institute of Ecology and Evolution named after A. N. Severtsov of the Russian Academy of Sciences. Instead of ash at the outlet the unit produces vitrified granular material that has been assigned V hazard class on the basis of biotesting. The practical value of the vitrified material has been approved: according to the report of the Tsemiskon Testing Center, cement with the addition of glass granulate as an additive corresponds to Portland cement with additives of CEM II/A type, 42.5H strength class. The vitrification technology has been fully developed for wastewater sludge and is ready for scale-up and commercialization.

Key words

sludge , sludge drying , sludge cake , vitrification , vitrified material , zero landfilling , pilot plant , thermal methods of utilization

DOI 10.35776/VST.2021.10.05
UDC 66.063.8

Grigor’eva Anastasiia, Abiev Rufat, Lobanov Fedor, Тарарыков Олег Юрьевич

Developing efficient methods of mixing during chemical treatment of wastewater suspension

Summary

In recent years the problem of wastewater sludge disposal has become more and more urgent for the municipal economy. The results of a study of the process of sludge suspending with Dezolak, a lime-containing agent, are presented; the size of solid inclusions is determined to provide for calculating the required rotation speed of the mixing device: the average Sauter particle diameter was 55 μm, the density of the solid phase was 2211 kg/m³. For effective chemical suspending the angular velocity of the mixer should be more than 0.03 m/s. The main similarity criteria for scaling the apparatus were investigated; it was determined that while choosing a mixer, the Froude criterion Fr should be taken into account, since that very indicator was practically constant for the three investigated reactors. Based on the work done, it was determined that the ratio of power to the volume of the mixed liquid cannot be a criterion for calculating devices equipped with GMS mixing devices: for these mixers, a decrease in the mixing power with an increase in the size of the device is valid.

Key words

wastewater , mixer , sludge utilization , lime mixing , lime-containing chemical

DOI 10.35776/VST.2021.10.06
УДК 614.777-628.112

Kapranov Sergei

Методика оценки состояния нецентрализованных источников питьевого водоснабжения в условиях чрезвычайной социально-экономической ситуации

Аннотация

Целью работы явилось обоснование необходимости организации и проведения на конкурсной основе благоустройства нецентрализованных водоисточников с использованием разработанной методики комплексной гигиенической и экологической оценки состояния нецентрализованных источников питьевого водоснабжения в условиях чрезвычайной ситуации. В работе использованы результаты многолетнего санитарно-гигиенического обследования и лабораторных исследований воды коллективных источников нецентрализованного питьевого водоснабжения. Определены следующие основные показатели для комплексной гигиенической и экологической оценки состояния нецентрализованных водоисточников: степень соответствия водоисточника установленным санитарно-гигиеническим и санитарно-техническим нормам и требованиям; соблюдение зон санитарной охраны; санитарно-просветительное, эстетическое и художественное оформление водоисточников; уровень благоустройства территории, окружающей водоисточники; качество воды водоисточников по результатам лабораторных исследований за определенный период. По каждому из пяти показателей предусмотрена оценка по 12-балльной шкале с последующим суммированием баллов с целью получения итогового результата комплексной оценки. Учитывая успешное проведение конкурса по благоустройству нецентрализованных источников водоснабжения с использованием разработанной методики комплексной гигиенической и экологической оценки состояния нецентрализованных источников питьевого водоснабжения в районе с резким дефицитом питьевой водопроводной воды, рекомендовано опыт проведения данного мероприятия распространить на другие административные территории, находящиеся в подобной ситуации.

Ключевые слова

emergency situation , water quality , нецентрализованный источник питьевого водоснабжения , methodology for a hygienic and environmental estimation of the water sources