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UDC 628.35:661.5
Danilovich Dmitrii, KOZLOV M. N., Moyzhes O. V., Nikolaev Yu. A., KAZAKOVA E. A., GRACHEV V. A.
Anaerobic Oxidation of Ammonium for Removal of Nitrogen from High-Concentrated Wastewater
Summary
The first in Russia study of the technique of anaerobic oxidation of ammonium (ANAMMOX) applied for treatment of return flows from dewatering of digested sludge is described. The two-stage technique ANAMMOX with the use of two processes – partial nitrification and the process of anaerobic oxidation of ammonium itself – has been realized under laboratory conditions. Efficiency of nitrogen removal in a reactor was 90%, volumetric capacity of the reactor by nitrogen was 0,16 kg/m3 per day. Results obtained show that the process of autotroph removal of nitrogen is an attractive alternative technologically and economically to the traditional technique of nitri-denitrification.
Key words:
wastewater , nitrogen removal , ammonium , anaerobic oxidation , nitrification , denitrification , dewatering of fermented sludge
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DOI 10.35776/MNP.2019.09.07
UDC 628.356
Bazhenov V. I., Ustiuzhanin A. V., Koroleva Ekaterina
Aeration for wastewater biological treatment: updating foreign terms and abbreviations
Summary
The study of domestic and foreign methods for aeration tanks evaluation and their design guidelines is presented. The analysis of modern approaches to the calculation of treatment facilities indicates that the calculated air flow rate is determined in accordance with the oxygen demand of the biological process for the oxidation of organic compounds, nitrification and denitrification. International terms and abbreviations have been adapted to Russian analogues taken in conjunction with the theory of oxygen mass transfer, as well as the international guidelines for the design of wastewater treatment facilities. The difference between the field (experimentally measured) and calculated (determined for the design) parameters OUR and AOR, SOTR and SOR is explained. Balance equality between OTR and AOR is an optimal and economical design solution. It is noted that the use of updated international terms and abbreviations in tender and competitive procedures (during design and delivery) will simplify their implementation and ensure mutual understanding between the parties. The need for regulation of the air supply to aeration tanks is justified by the balance of oxygen «consumption – transfer». In dynamic conditions for regulated systems OTR → OUR. With the automated maintenance of the set point for the concentration of dissolved oxygen this condition provides for the savings in energy consumption.
Key words
wastewater , biological treatment , nitrification , denitrification , aeration tank , aeration system , oxygen mass transport , terms , abbreviations , air flow rate control , OUR , AOR , OTR , SOTR , SOTE
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DOI 10.35776/VST.2021.04.03
UDC 628.35:661.5
Pukemo M. M., Koulakov A. A., Zheltukhin Roman
Features of hospital wastewater treatment
Summary
At high concentrations of nitrogen compounds and low concentrations of organic substances in wastewater, the process of denitrification does not proceed in full, resulting in a high concentration of nitrates in the effluent. The experience of using an extra substrate to supply the denitrified nitrate nitrogen with the required organic matter is described. Deep suppression of biocenosis at high concentrations of chlorine derivatives in raw wastewater was revealed. At a total chlorine concentration of 5.4–6.8 mg/l, neither biological treatment processes proceeded, nor a biofilm formed on the media surface. It is noted that the composition of the hospital wastewater is characterized by a low concentration of organic matter (BOD5 was on average 42.3 mg/l, COD – on average 128.9 mg/l) with a total nitrogen concentration of 43.4 mg/l. The effectiveness of using sucrose as a substrate for the denitrification of hospital wastewater has been experimentally confirmed. The sugar consumption was 0.17 kg/m3 at the ratio of BOD5/total nitrogen of 0.95 in the incoming wastewater.
Key words
treatment facilities , denitrification , hospital wastewater , extra substrate , sucrose
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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.
key words
biological treatment , nitrification , denitrification , nitrogen , phosphorous , activated sludge , kinetic constants , process design method , industrial and municipal wastewater
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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.
Key words
wastewater , biological treatment , nitrification , denitrification , activated sludge , kinetic constants , theoretical and empirical mathematical models , comparative calculation of the biological treatment facilities , ASM2d
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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.
Key words
wastewater , biological treatment , nitrification , denitrification , activated sludge , kinetic constants , theoretical and empirical mathematical models , ASM2d , NII VODGEO/SamGTU methodology , enzyme kinetics equations , comparative calculation
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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.
Key words
biological treatment , nitrification , denitrification , activated sludge , kinetic constants , industrial and municipal wastewater , VODGEO/SamGTU and ASM2d process calculation methods , theoretical and empirical mathematical models , comparative calculation of the biological treatment facilities
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DOI 10.35776/VST.2022.09.04
UDC 628.35
Kevbrina M. V., Dorofeev A. G., Agarev Anton
Comparison of the results of calculating aeration tanks according to different methods (for discussion)
Summary
The calculation results are compared according to the method described in the book by D. A. Danilovich and A. N. Epov «Calculation and technological design of processes and facilities for the removal of nitrogen and phosphorus from municipal wastewater», and the method given in the book «Wastewater technology. Processing and recovery of resources» (fifth edition, Metcalf & Addy), in a model unit, for which earlier in the article by V. N. Shvetsov, S. V. Stepanov and O. V. Khar’kina «Comparison of the calculation results for aeration tanks using the NII VODGEO/SamGTU and ASM2d models» calculations had been made according to the method of NII VODGEO/SamGTU and following the model developed by ASM2d. It is shown that calculations based on the equations of enzymatic kinetics and microbial growth (NII VODGEO/SamGTU, ASM2d and Metcalf & Addy) give similar results in terms of the volume of aeration tanks with the «tabular» method based on the German standard ATV-DVWK-A131E and revised taking into account the growth kinetics of nitrifying microorganisms. The difference in approaches gives different results as for the age of activated sludge; however, the final results of the volumes of aeration tanks and zones in them have discrepancies that do not exceed 15–20%. Simulation of the operation of aeration tanks in BioWin-3 program, designed on ASDM model that is essentially close to the ASM group of activated sludge models, with zone volumes calculated using different methods, showed a similar calculated quality of effluent. This confirms the possibility of any of the considered methods to adequately calculate the volumes of aeration tanks. The choice of the calculation method for each specific case depends on the availability and ease of use of the methodology, as well as on the personal preferences of the designer.
Key words
nitrification , denitrification , aeration tank , wastewater biological treatment , anaerobic zone , theoretical and empirical mathematical models , comparative calculation of the biological treatment facilities , technological calculation methods , anoxic zone
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UDC 628.35:661.5
Danilovich Dmitrii, Smirnov Aleksandr Vladimirovich
The technology of step-feed nitri-denitrification in municipal wastewater treatment: the analysis of options and case record
Summary
The experience of MY PROJECT JSC in designing biological treatment facilities (aeration tanks) at the municipal treatment facilities of the Russian Federation with the use of step-feed nitri-denitrification is considered. Over the past 10 years more than 20 treatment facilities have been upgraded and built with the introduction of a step-feed scheme; the author of the article made a personal commitment in commissioning of more than 10 biological treatment facilities for municipal and industrial wastewater processing. In order to observe the data confidentiality, no data is provided on the chemical analysis of the operation of structures; however, with the help of mathematical modeling, the specific features of the implementation of step-feed denitrification are shown. The key process engineering aspects of the implementation of the schemes of a step-feed process with a different number of stages (two and three), cases of the need to use or reject nitrate recycling, as well as using, where applicable, an additional substrate (methanol) with particularly stringent requirements to the nitrogen concentration at the effluent discharge are considered. Traditionally, it is believed that the scheme of step-feed denitrification is designed for nitrogen removal; however, additional positive modifications of step-feed denitrification have been also considered that provide for arranging biological removal of phosphorus. The design of an anaerobic zone upstream the first denitrification cascade (D1), the use of step-feed denitrification in the implementation of the process scheme of the University of Johannesburg (JHB), as well as the arrangement of step-feed of return sludge are considered.
Key words
biological treatment , nitrification , denitrification , aeration tank , biological phosphorus removal , step-feed technology
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