Tag:kinetic constants

№12|2016

WASTEWATER TREATMENT

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UDC 628.31:661.5

MOROZOVA K. M., Stepanov S. V., Stepanov A. S., Sokolova T. V., Solkina O. S., Zhukova M. A.

Biological treatment of dairy industry wastewater in a membrane bioreactor (part 1)

Summary

The results of research study in the field of biological treatment of dairy wastewater are presented. The studies carried out under contact conditions showed that the kinetics of oxidation of dairy wastewater pollutants with activated sludge can be described by enzymatic reactions equation for substrate inhibition; at that, the obtained inhibition constants point at the increase of the wastewater toxicity after chemical flotation for biological treatment processes. The technology has been proved with simulative effluent in a pilot membrane bioreactor. The kinetic dependences of organics oxidation by BODfull, nitrification and denitrification were determined. The increase of oxidation capacity of the facilities by 1.46 at the sludge concentration increase from 4 to 10 g/l is shown that allows reducing significantly the size of the biological treatment facilities when using MBR technology. In the course of experimental studies at MBR plant and kinetic experiments under contact conditions the coefficients of inhibition with activated sludge metabolism products were determined for the simulative solution of wastewater by BODfull, for nitrification and denitrification. The temperature constant value for aerobic heterotrophic conversion, for nitrification and denitrification processes has been found.

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№10-2|2010

WASTEWATER TREATMENT

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UDC 628.35:663.5

Aronova T. A.

The Use of Bioblocks at Wastewater Treatment Facilities

Summary

Results of the experimental study of development of a flow chart of wastewater treatment at distilling plants processing the grain raw material are presented. A two-stage flow chart with sludge separation at each stage is rational for such processes. The process of biochemical oxidation of organic pollutants in the course of biological treatment of concentrated wastewater of distilling plants is described the most reliably with the equations of fermentative reactions. Kinetic constants and oxidation coefficients for this type of wastewater in two-stage aeration tanks have been determined; technological parameters of aeration tanks operation up to any desired level of treatment ensuring the conditions of treated wastewater discharge have been calculated on the basis of them. Optimizing calculations have been made and technological parameters of the optimal conditions of the two-stage aeration tank operation up to indicators of complete biotreatment have been determined according to these kinetic constants determined.

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№10|2022

WASTEWATER TREATMENT

DOI 10.35776/VST.2022.10.05
UDC 628.35

Stepanov S. V., Avdeenkov Pavel, Ponomarenko Ol’ga, MOROZOVA K. M.

Determination of kinetic constants and coefficients of biological processes of wastewater treatment of egg advanced processing enterprises

Summary

The results of studies carried out in contact conditions with active sludge of a laboratory batch reactor with wastewater from an enterprise for advanced processing of chicken eggs are presented. In the course of kinetic experiments based on measuring the rate of dissolved oxygen consumption the following averaged values of the kinetic constants of the biological treatment processes were established for wastewater after preliminary coagulation: the maximum rate of oxygen consumption at a sludge concentration ai → 0 ρ`max = 44.8 mg/(g·h) in terms of a temperature of 20°С; Michaelis constant Km = 77.5 mg/l; coefficient of inhibition by metabolic products φ=0.265; temperature constant χ = 0.08°С–1; optimal pH value 7.8 and pH constant 80. During the experiments with raw wastewater, the following average values of the constants were determined: the maximum rate of oxygen consumption at 20°С and ai → 0 ρ`max = 26.5 mg/(g·h); Michaelis constant Km = 50.6 mg/l; coefficient of inhibition by metabolic products φ=0.065; temperature constant χ = 0.1°С–1; pHopt 7.8 and KрН = 170. The obtained values of kinetic constants and coefficients can be used in the calculation of biological wastewater treatment facilities of an egg processing enterprise.

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№9|2018

WASTEWATER TREATMENT

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UDC 628.35

SHVETSOV V. N., MOROZOVA K. M., Stepanov S. V.

Designing facilities for municipal and industrial wastewater biological treatment in aeration tanks with nutrients removal

Summary

Biological treatment facilities are the basic facilities for the purification of domestic, municipal and industrial wastewater of most of the industries (chemical, petrochemical, oil refining, food, textile, consumer goods, coke-chemical industries, agriculture etc.). However until now there has been no scientifically-grounded method of designing wastewater biological treatment facilities with nitrogen and phosphorus removal in the Russian Federation. Many years of extensive research carried out by NII VODGEO and «Water Supply and Wastewater Disposal» chair of the Samara State Technical University at the laboratory and pilot plants, at the operating facilities with processing data bulks provided for developing an adequate method of designing aeration tanks with nutrients removal. The presented method is a supplement of the method of process design of biological treatment facilities stated in SNiP 2.04.03-85 with regard to designing aeration tanks with nitri-denitrification and biological phosphorus removal; and provides for the calculations of upgrade and new construction of the facilities for biological treatment of municipal, domestic and industrial wastewater. Behind the process design is the concept of the process description with enzyme kinetics equations. The method includes the following stages: substantiation of the relevant basic data on the flow rates and qualitative composition of wastewater; determination of the process flow scheme and burden balance calculation of all the critical pollution components; determination of the kinetic constants and coefficients of enzyme kinetics equations of the transformation of each basic pollution component (BOD, nitrogen compounds, phosphorus etc.) and activated sludge growth by the statistical analysis of the operation data and chemico-analytical analysis of wastewater samples of the operating treatment facilities, by experimental data or on the basis of the available analogies; calculation of the volume of all the elements of the facilities with determination of the limitative component and treatment level in relation to other pollutants; final correction of the vo­lumes and parameters of all the process zones with account of the requirements to the level of treatment in relation to all the dictating pollution components. An example of the calculation is set. It is noted that the computation algorithm and formulas included into the method provide for designing any complicated process flow schemes with nitrogen and phosphorus removal applied both to municipal and industrial wastewater. The method provides for calculating not only the rate of removing BOD and nitrogen compounds but also other certain pollution components (oil products, detergents, fats etc.) offering additional opportunities of the wastewater biological treatment method. The method is especially useful in designing industrial wastewater biological treatment facilities because most of the foreign methods are mainly focused on the purification of domestic and municipal wastewater to the concentrations adopted in those countries. The method is developed on the principle of essential sufficiency; however is contains 70 design parameters and 28 formulas and equations. Accordingly the calculations are performed in Microsoft Office Excel which makes it possible for users even with middle software skills. Herewith it is possible to perform calculations straight for several options interactively and/or upgrade the treatment facilities in the process of their operation.

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№11|2013

WASTEWATER TREATMENT

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UDC 628.35:661.5

SHVETSOV V. N., MOROZOVA K. M.

Procedure of designing wastewater biological treatment facilities
with nutrients removal

Summary

The procedure of designing wastewater biological treatment facilities with nitrification-denitrification is presented. Biological treatment facilities shall be designed on the basis of experimentally determined kinetic constants, nitrification and denitrification process factors, and for every limiting value depending on the requirements to the quality of treatment. Kinetic constants and factors required for designing municipal wastewater treatment facilities are given. Design algorithm is set out including the following stages: substantiation of the initial data on flow rates and qualitative wastewater composition according to the required level of reliability (more than 85–90% probability); selection of the process flow scheme – number of steps and(or) stages, operation procedure and lay out; determination of kinetic constants of equations of enzyme kinetics of every basic pollution component transformation from experimental data or from the available data base; preliminary calculation of excess activated sludge volume and adjustment of nitrogen and phosphorus mass balance; determination of limiting pollution component that needs maximum time to be oxidized; calculation of the facility capacity by limiting component with determination of the treatment level for other pollution components. The results of the long-term experimental studies of nitrification-denitrification processes with different types of municipal and industrial wastewater provide for supplementing the method of aeration tank design specified in SNiP 2.04.03-85 with formulae and data for design and optimization of aeration tank operation with nitrogen and phosphorus removal.

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№12|2022

WASTEWATER TREATMENT

DOI 10.35776/VST.2022.12.04
UDC 628.35

Stepanov S. V., Avdeenkov Pavel, Ponomarenko Ol’ga, MOROZOVA K. M.

Results of studying biological treatment of wastewater of an egg processing enterprise in a pilot membrane bioreactor

Summary

The results of studies on the biological treatment of wastewater of an enterprise for advanced processing of chicken eggs in a pilot membrane bioreactor (MBR) with preliminary denitrification are presented. It is shown that the key indicator of pollution the treatment facilities shall be calculated on is BODtotal. At loads on the ash-free basis of activated sludge according to BODtotal from 0.06 to 0.125g/(g·day) for raw wastewater and from 0.04 to 0.12g/(g·day) for wastewater after preliminary coagulation and settling, BODtotal of permeate was 8–12 mg/l, and the concentrations of ammonium and nitrite met the MPC for fishery water bodies. The minimum recirculation that provided for the concentration of nitrate nitrogen in the effluent at the MPC level, turned out to be eight-fold for raw wastewater and six-fold for the pre-coagulated one. The inert part of COD was about 90 mg/l. On the basis of the executed studies the kinetic constants of the oxidation of organic substances required for the calculation of industrial biological treatment facilities were determined: ρ´max for BODtotal – 29.9 and 30.4 mg/(g·h), Km for BODtotal – 34.7 and 25.2 mg/l for raw wastewater and wastewater after preliminary physical and chemical treatment, respectively. The total volumes of bioreactors with a capacity of 600m3/day, operating with an activated sludge dose of 8 g/l according to the MBR technology with preliminary denitrification, while providing for the treatment level of BODtot of 12 mg/l and removing nitrogen compounds to the MPC for fishery water bodies, amounted to 3716 and 1643m3 for raw wastewater and wastewater after preliminary physical and chemical treatment, respectively.

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№7|2021

WASTEWATER TREATMENT

DOI 10.35776/VST.2021.07.03
УДК 628.35

Kharkina O. V., Iskalieva Karina, Malich Ekaterina

Comparison of aeration tank calculations using ASM2d and ATV models

Summary

A comparison is made of the results of calculating aeration tanks by ATV model (Standard ATV-DVWK-A131 E «Dimension of Single-Stage Activated Sludge Plants 2000»), that is a stochastic «table» model, and by ASM2d model, that is referred to as theoretical and describes, unlike ATV, biological wastewater treatment processes using enzymatic kinetics formulas. Calculations are performed for the same input data. The calculation results show essentially limited use of ATV model; this model, as originally given in the description of this model by the designers, provides for calculating aeration tanks only for a single value of the effluent quality in terms of ammonia nitrogen as 1 mg/l and does not provide for calculating aeration tanks in terms of nitrites. Moreover, the comparison of ATV and ASM2d show that achieving the specified quality of effluent in terms of ammonia nitrogen as 1 mg/l is possible only at specific values of the kinetic constants determined by the authors in this article; whereas, any change in at least one kinetic parameter of the wastewater results in an increase in the required aerobic age of activated sludge and, as a consequence, in the calculated volume of the aerobic zone by tens of percent, which proves the risk of not achieving the required effluent quality while using ATV model even for ammonium nitrogen concentration of 1 mg/l. Taking into account the fact that ATV Method does not provide for calculating aeration tanks for the effluent quality in terms of nitrites, the results of our calculation show that the aerobic age of activated sludge of 4.05 days for a temperature of 17 ºС proposed in ATV will make it possible to achieve the effluent quality in terms of nitrite nitrogen, 0.35–0.52 mg/l N–NO2, proving the unavailability of ATV, if the requirements to the effluent quality in terms of nitrites are specified. The authors, on the basis of the calculations, make conclusions about the risk of failure to achieve the effluent quality in terms of ammonia nitrogen as well as 1 mg/l while using ATV, because ATV is a stochastic model, that is, all dependencies presented in this method have been determined for the specific operating conditions. Moreover, as specified in the ATV description, this method, even in limited conditions, is applicable strictly for urban wastewater. The calculations show that if there are requirements for the effluent quality in terms of nitrites, regardless of the required concentration value of nitrites, the ATV method is absolutely not suitable, while ASM2d, taking into account the fact that it is based on the formulas of enzymatic kinetics, provides for calculating aeration tanks for any required effluent quality in terms of both ammonium nitrogen and nitrite nitrogen and is applicable for any type of wastewater.

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№5|2022

WASTEWATER TREATMENT

DOI 10.35776/VST.2022.05.03
UDC 628.35

Kharkina O. V.

Comparison of the results of calculating aeration tanks according to the method of Danilovich–Epov and ASM2d model (part 1)

Summary

The analysis of the method proposed by D. A. Danilovich and A. N. Epov for calculating aeration tanks that implement nitrogen and phosphorus removal technologies is carried out. A comparison of the results of calculations by this method and ASM2d method is given. It is shown that, in contrast to the ASM2d method that refers to theoretical models and describes the processes of biological wastewater treatment using the formulas of enzyme kinetics, the method under consideration is, in essence, an empirical calculation that contains constants that are invariable and, for the most part, not having the physical meaning. Since empirical models make a connection between the parameters obtained on the basis of the experimental data of a particular object under strictly limited conditions, these models can only be applied if all the parameters of another object exactly match the data of the object the proposed model was compiled for. Accordingly, using any empiric models, including the method under consideration, at the facilities that were not the objects for the compilation of these empiric models, leads to the risk of obtaining incorrect calculation results. Based on the performed calculations, the risks and constraints of using the method proposed by Danilovich and Epov for the calculation of biological treatment facilities are shown. In the first part of the paper, a design analysis was carried out to determine the values of the aerobic age of activated sludge that were the basic values for calculating the volume of aerobic zones of aeration tanks.

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№11|2022

WASTEWATER TREATMENT

DOI 10.35776/VST.2022.11.03
UDC 628.35

Kharkina O. V.

Comparison of the results of calculating aeration tanks according to the method of Danilovich–Epov and ASM2d model
(рart 2)

Summary

The analysis of the method for calculating aeration tanks proposed by D. A. Danilovich and A. N. Epov, based on the German ATV method, is continued. Due to certain limitations of the empirical ATV methodology developed on the basis of the data on the wastewater the authors were able to study, the ATV methodology cannot be applied anywhere except the treatment facilities where those studies were carried out. The Methodology has been compared with ASM2d model (a matrix of enzyme kinetics equations describing the growth rates of microorganisms and the rates of the corresponding biochemical processes), as well as with the NII VODGEO/SamGTU method that is a completely theoretical model, and the calculation formulas being enzyme kinetics equations. Calculations of aeration tanks according to the formulas of enzyme kinetics were laid down in SNiP «Sewerage. External Networks and Structures» in 1974; whereas in SNiP 1984, the calculation was given in the form of a proven methodology for biological treatment facilities for the oxidation of organic compounds. The empirical approach proposed in the Methodology opens not only a technological question about the scope of its application, but also the question of its expediency in general. The use of empirical approaches, to which the Methodology belongs, formally connects the inherent parameters in the form of invariable coefficients and empirical dependencies obtained experimentally in a narrow range of parameters and conditions of a particular object bringing the risks of significant errors. It is shown that the Methodology for municipal wastewater provides for underestimated volumes of aeration tanks by tens of percent compared with the results of calculations using the theoretical methods ASM2d and VODGEO/SamGTU developed by V. N. Shvetsov, S. V. Stepanov, K. M. Morozova that describe wastewater treatment processes using enzyme kinetics formulas. Herewith, it is shown that ASM2d and the VODGEO/SamGTU methodology give a high convergence of the results within differences of less than 10% which allows to speak about the robustness of the ASM2d model and the VODGEO/SamGTU methodology, and the limitations of the Method that can be used only for rough estimates.

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№5|2021

WASTEWATER TREATMENT

DOI 10.35776/VST.2021.05.02
UDC 628.35

SHVETSOV V. N., Kharkina O. V., Stepanov S. V.

Comparison of the calculation results for aeration tanks using the NII VODGEO/SamGTU and ASM2d models

Summary

Проведено сравнение результатов расчета аэротенков, реа­лизующих процессы аэробного окисления органических сое­динений, нитрификации, денитрификации и удаления фосфора (химического и биологического) по двум различным математическим моделям (методикам): ВОДГЕО/СамГТУ (Самарского государственного технического уни-
The paper presents a comparison of the results of calculating aeration tanks where the processes of aerobic oxidation of organic compounds, nitrification, denitrification and phosphorus removal (chemical and biological) according to two different mathematical models (methods): VODGEO/SamGTU (Samara State Technical University) and ASM2d have been implemented. These models are theoretical and describe the processes of biological wastewater treatment using enzymatic kinetics formulas. Calculations for the same input and output data showed a high reproducibility in terms of the volumes of the process zones of aeration tanks. For the quality of effluent meeting the MPCs for fishery water bodies (option 1), the discrepancy is –0.3 and 3.3%, respectively, for the anoxid and aerobic zones. With indicators for effluent discharge into a water body of category B (option 2) for large-scale to extremely large-scale facilities, the difference in the results of calculating the volumes was 13.8 and 15.4%, respectively. While making calculations with account of the effluent quality reaching the process indicators for discharge into a water body of category G (option 3) for large-scale to extremely large-scale facilities, the discrepancy in the values of the volumes of aerobic zones was 48% owing to the expediency of ensuring stable nitrification at high loads. Therefore, option 3 according to the VODGEO/SamGTU method was actually performed for a lower sludge load and more enhanced nitrification than according to the ASM2d method (1 instead of 2 mgN–NH4/l). It is shown that the mathematical models underlying both methods, based on the fundamental equations of the enzymatic reaction, a very high reproducibility and consistency of the calculation results give grounds to assert that both of these models are, to the greatest extent known, acceptable for calculating biological treatment facilities with the removal of nitrogen and phosphorus.

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