DOI 10.35776/VST.2022.06.03
UDC 628.35:665.666.6
Kevbrina M. V., Gavrilov Dmitrii, Belov N. A., Agarev Anton
Analysis of the operation of acidifiers after the reconstruction of the block of the Liuberetskie Wastewater Treatment Facilities
Summary
Municipal wastewater in Moscow after primary settling contains insufficient organic matter for the sustainable removal of nitrogen and phosphorus to the standard quality during treatment. Therefore, while designing the reconstruction of the old block of the Liuberetskie Wastewater Treatment Facilities in Moscow, the acidification (prefermentation) method was chosen as the most efficient process solution for enriching wastewater with easily decomposable organic matter (obtaining organic acids during acidic fermentation of raw sludge from primary settling tanks). Upon the completion of the reconstruction of the old LWWTF block at the end of 2021, primary sludge acidifiers were put into operation. Launching acidifiers provided for enriching primary water with easily decomposable organic matter (volatile fatty acids, including acetate) resulting in the improved efficiency of denitrification and biological dephosphorization processes in the aeration tanks. Two or three weeks after the acidifiers had been put into the operation mode, the quality of effluent for nitrogen as nitrates and phosphorus as phosphates was meeting the MPC for fisheries. The process parameters of the acidifiers (hydraulic retention time, residence time for dry matter, the rate of volatile fatty acids formation, the degree of recirculation, the dry matter concentration in the incoming flow) corresponded to those recommended in the literature. Possible situations of abnormal operation of acidifiers have been analyzed and recommendations have been developed to eliminate the causes.
Key words
nitrogen removal , wastewater treatment , acidification , readily available organic matter , prefermentation , phosphorus elimination , process parameters of the acidifiers’ operation
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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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UDC 628.35:661.5
Zoubov M. G., Boyarenev S. F., Zoubov G. M., Koulikov N. I., Shramov Yu. M., Litty Yu. V., Nekrasova V. K., Nozhevnikova A. N.
Wastewater treatment biotechnology with activated sludge immobilization and nitrogen removal
Summary
The data on the development and introduction of advanced wastewater treatment biotechnology with activated sludge immobilization and nitrogen removal with the use of Anammox bacteria are presented. On the basis of laboratory studies and pilot tests full-scale wastewater treatment facilities have been designed. Their operation provides for the high economic, environmental and social effect.
Key words
wastewater , biological treatment , nitrogen removal , activated sludge immobilization , anammox bacteria
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UDC 628.356:661.5
KOZLOV M. N., Nikolaev Yu. A., GRACHEV V. A., Kharkina O. V., Dorofeev A. G.
Nitrification in the Course of Tertiary Treatment of Treated Wastewater with Floating Media
Summary
For complete oxidation of ammonium nitrogen at a wastewater aftertreatment stage it is proposed to use a bioreactor with floating media containing nitrifying microorganisms. Tests of the technology have been conducted with treated wastewater at the Kurianovskiye treatment facilities using the laboratory bioreactor with floating plastic media (60% by volume). After achievement of stable conditions of the bioreactor’s operation the technology proposed has ensured the reduction of ammonium nitrogen concentration by 4,8 mg/l at the average. Reasons for the reduction of efficiency of the bioreactor’s operation and appearance of nitrite-ions in the treated water when changing the technological conditions are presented.
Key words
nitrogen removal , nitrification , bioreactor , wastewater , floating media
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UDC 628.35:661.63
KOZLOV M. N., Kevbrina M. V., Nikolaev Yu. A., Dorofeev A. G., GRACHEV V. A., KAZAKOVA E. A., Aseyeva V. G., Zharkov A. V.
Single-reactor technology of nitrogen removal from wastewater
Summary
The experts of R&D Centre of «Mosvodokanal» OJSC developed high-effective technology of removing nitrogen from wastewater. The technology was tested at the Kur’ianovo wastewater treatment plant of the city of Moscow during processing filtrate of the digested sludge belt thickeners. The method is based on the use of specific Anammox-bacteria that oxidize ammonium with nitrite under anoxic conditions. Filtrate is processed in a sequencing batch reactor with complete mixing (SBR-reactor). Partial nitrification processes (ammonium oxidation into nitrite), ammonium oxidation with nitrite and organic matter oxidation are carried out in one reactor. Retention of extremely slow growing biomass of Anammox-bacteria has been a critical problem for all the reactors. In this particular case the problem was solved with bacteria adhesion on the reactor walls and the feed as well as with flotation. To evaluate the treatment efficiency standard methods were used. The developed single-reactor modification of the anoxic oxidation of ammonium differs from the well-known by the following parameters: high nitrogen removal efficiency, the method of biomass bacteria retention in the reactor, the availability of new Anammox bacteria, heterotrophic denitrification. All other conditions being equal the integration of Anammox single-reactor technology requires the size of the facilities ten times smaller than double-reactor technology; for this reason it is more preferable for implementation. The new technology was given the name AUTOHETAMMOX.
Key words
wastewater , nitrogen removal , bioreactor , nitrification-denitrification , anammox bacteria
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UDC 628.35:661.5
К. Вун, Lemaire Romain, Zhao Hong, Christensson Magnus, M. Le Noir
Experience from start-up and operation of deammonification MBBR plants, and testing of a new deammonification IFAS configuration
Summary
A single-stage deammonification process utilizing biofilms on moving carriers in a mixed reactor (ANITA™Mox) is studied. Partial
nitritation and autotrophic N-removal occur simultaneously within the biofilm, where aerobic and anoxic zones result from oxygen mass transfer limitation. Ammonium oxidizing bacteria (AOB) oxidize NH4 to NO2 in the aerobic zone of the biofilm (i. e. external biofilm) while Anammox bacteria (AnAOB) located in the anoxic zone of the biofilm (i. e. internal biofilm) consume NO2 produced by AOB together with the excess NH4. The process has been implemented at full-scale as a Moving Bed Biofilm Reactor (MBBR) to treat reject water from dewatering of digested sludge. Startup of these installations was accelerated using a seeding strategy whereby 3–15% of carriers with established AOB/AnAOB biofilm were mixed with new carriers. N-removal rates up to 1.2 kgN/(m3react·d) have been observed in the full-scale process. The achievable rate is influenced by substrate transport inside the biofilm, which depends on factors such as biofilm density, thickness, temperature, and substrate concentrations. One possible strategy to increase the N-removal is to enhance substrate transport. Using Integrated Fixed-Film Activate Sludge (IFAS) to separate the nitritation and anammox reactions spatially, instead of adjacent in the same biofilm, allows the AOB to grow in suspended phase to better utilize DO, while allowing the biofilm to specialize in AnAOB reaction to achieve higher rates. A lower bulk DO can be used in this mode. Results from full-scale ANITA™Mox MBBR treating sidestream effluent are presented together with preliminary ANITA™Mox IFAS results from a 50 m3 full-scale prototype showing an increase in N-removal rate of up to 3 times that usually achieved in pure MBBR configuration.
Key words
nitrogen removal , Anammox , ANITA™Mox , IFAS , MBBR
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UDC 628.35:665.666.6
DOI 10.35776/VST.2023.02.06
Kevbrina M. V., Gavrilov Dmitrii, Belov N. A., Agarev Anton
Industrial tests at the Kur’ianovskie Wastewater Treatment Facilities involving the transfer of one primary settling tank into the acidification mode
Summary
In the process of Moscow wastewater treatment primary effluent is lacking enough organic substances for sustainable removal of nitrogen and phosphorus to meet the regulations. One of the methods of enriching wastewater with easily decomposable organic matter is acidification (acid fermentation) of raw sludge. At the Kur’ianovskie Wastewater Treatment Facilities in Moscow industrial testing was conducted at the first new treatment block operating according to the UCT process flow scheme with a design capacity of 600 thousand m3/day on transferring one settling tank into the acidification mode. Of the four settling tanks of the block, raw sludge from the three primary settling tanks operating in the clarification mode was fed to the fourth one operating in the acidification mode. Wastewater flow rate for the acidifier was 30–100% of the flow rate of each of the primary settling tanks, or 11–25% of the water flow rate of the block. The acidified sludge recycling was 100% with respect to the raw sludge flow, or 3% with respect to the mixture of raw sludge and wastewater entering the acidifier. The residence time of the sludge in terms of dry matter (SRT) in the acidifier changed during the experiment from 2 to 3.5 days; the highest treatment efficiency in relation to removing nitrogen and phosphorus compounds was achieved with a residence time of 3.5 days. The hydraulic residence time of wastewater in the settling tank-acidifier (HRT) ranged from 1.9 to 5.5 hours and did not have a noticeable effect on the rate of removing nitrates and phosphorus as phosphates at the next biological stage. The arrangement of the operation of the primary settling tank in the acidification mode showed the presence of the effect of this process that contributed to the additional removal of 3.5 mg/l of nitrogen as nitrate and 0.23 mg/l of phosphorus as phosphate, and provided for the treatment level up to BAT standards. The average concentration of nitrogen as nitrates in the effluent decreased from 11.6 to 8.1 mg/l. For phosphorus as phosphate, before the introduction of acidification at the facilities, the standard effluent quality was provided; however, the enrichment of wastewater in the process of acidification with easily decomposable organic matter contributed to a decrease in the concentration of phosphate phosphorus from 0.35 to 0.12 mg/l. The transfer of one primary settling tank to the acidification mode provided for implementing the acidification process eliminating the construction of acidifiers as separate tanks.
Ключевые слова
nitrogen removal , wastewater treatment , acidification , readily available organic matter , prefermentation , phosphorus elimination , process parameters of the acidifiers’ operation
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UDC 628.35:661.5
Nikolaev Yu. A., KAZAKOVA E. A., Kharkina O. V., Dorofeev A. G.
Nitrogen Removal from Return Flows of Sludge Treatment Facilities by Means of Nitri-Denitrification Without an Additional Source of Carbon
Summary
Results of the study of the process of simultaneous nitri-denitrification using the nitrite for removal of ammonium from the filtrate of belt thickeners of digested sludge at the Kuryanovo treatment facilities are presented. Introduction of the developed technology of biological treatment of wastewater containing ammonium nitrogen of high concentration and stripped with organic compounds readily oxidized without an additional source of organic carbon makes it possible to obtain the high efficiency of removal of nitrogen, suspended substances, COD, BOD5. Microorganisms capable to make denitrification using the organic substances not easily available that determines properties of activated sludge have been separated from activated sludge of a laboratory reactor.
Key words
filtrate , nitrogen removal , return flows , simultaneous nitri-denitrification , belt thickener , digested sludge of wastewater
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