Choosing the optimal water supply schematic for a high-rise building

Summary

The task of enhanced studying scientific substantiation of the selection of a water supply system schematic with the development of criterial indicators (parameters) of optimization is formulated. The analysis of the state of real estate construction market provided for making a substantiated choice of a model building for which seven different versions of water supply schematic were designed and hydraulic and technical and economic calculations were made. The core indicators of reliability were calculated with the use of three methods. The significance coefficients are proposed that determine the degree of impact of a single assembly failure on the general system robustness. The regularities of the fitting failure-free operation probability changing with increasing the number of storeys in a building were determined. An algorithm of choosing an applicable water supply schematic was drawn up that was based on the question-answer method and took into account the basic data on the number of storeys, pressure limitations, building design features, redundancy possibility and (or) necessity as well as additional equipment installation. The optimization parameters were determined: material characteristics, reliability and energy consumption. To solve the formulated task a uniform integral equation of reliability-economic index is proposed. The coefficients and all relevant numerical values assumed depending on the schematic under consideration are cited. Inserting basic data into the equation provides for the coordinates for definition domain development. Each schematic in view of its specificity has a definite range of values (definition domain).

Key words

reliability , energy efficiency , electric power , algorythm , water supply schematic , high-rise building , material characteristics , optimization parameter , definition domain

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UDC 628.292.003.13

Bazhenov V. I.

Customer benefit from the practical application of «7 = 2» initiative

Summary

The method of selecting pumping equipment by Life Cycle Cost (LCC) criterion – total cost of ownership is presented. The software that provides for calculating LCC criterion depending on the pump output is placed at www.7-2.su Web site. Submersible pumps are selected as a LCC calculation object because of their wide use at the sewage pumping stations under construction or subject to upgrade.

Key words

sewerage pumping station , impeller , electric power , submersible pump

DOI 10.35776/VST.2022.01.08
UDC 628.355:543.635.355:504.7

Kofman V. Ya.

Upcoming trends of processing waste activated sludge.
Preparation of volatile fatty acids (a review)

Summary

Among the methods of obtaining products with higher added value from waste activated sludge, produced avoiding the emission of greenhouse gases, anaerobic digestion is considered as a viable alternative to biogas production to obtain volatile fatty acids as the final product, that are an intermediate product of methane production in the traditional process. The main factors affecting the production of volatile fatty acids are considered, including pH value, temperature, C/N ratio, process duration, organic matter load of the fermenter, and the presence of microelements. An effective way of increasing the yield of volatile fatty acids is the combined digestion of waste activated sludge and substrates with a high organic carbon concentration (food waste, corn stover, manure, wastewater from dairy and pulp-and-paper production, filtrate from solid waste landfills), as well as pretreatment methods: physical (ultrasonic, microwave, thermal), chemical (alkaline treatment, free nitrous acid, metallic iron, peroxomonosulfate, etc.) and biological (biological surfactants, hydrolytic enzymes, hydrolytic bacteria) ones. The main fields of application of volatile fatty acids are presented including the preparation of medium-chain fatty acids, the production of polyhydroxyalkanoates, protein of single-cell organisms, electricity, hydrogen, as well as the use as a carbon source in the process of biological nitrogen removal.

Key words

surplus active silt , anaerobic fermentation , electric power , volatile fatty acids , polyhydroxyalkanoates , protein of unicellular organisms , medium-chain fatty acids , hydrogen , additional carbon source

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UDC 628.2:621.311.16+654.032.3

Avendin A. P., Filimonov A. V., Shatalov V. S.

Economic Appropriateness of Two-Rate Tariff of Payment for Energy at a Sewage Pumping Station

Summary

Conditions under which the payment for energy consumed by the sewage pumping station according to the two-rate tariff would be reasonable economically are considered. The payback period of modernization is determined on the example of the concrete pumping station.

Key words:

wastewater , sewerage pumping station , pump , electric power , tariff , output

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UDC 628.3:658.26.004.18

Danilovich Dmitrii

Energy conservation and alternative power sources at the wastewater treatment facilities

Summary

Methods of improving power efficiency of the municipal wastewater treatment facilities and heat and electrical power generation with the use of renewable power resource of wastewater. The analysis of power conservation and generation in water supply and wastewater management shows that depending on the technical solutions applied the total balance of power consumption at the water and wastewater facilities can vary from the net electrical energy consumption of 4 MW per 100 000 m³ of wastewater/day to positive balance of 7,5–8 MW (owing to 16 MW power generated including 1 MW of electrical energy). The power consumption of two independent municipal wastewater treatment plants can differ more than 6 times.

Key words

treatment facilities , wastewater , sludge , energy efficiency , electric power , power consumption , biogas , water supply-sewerage services , heat pumps