UDC 579.695+579.8

Gogina Elena, Bazhenov V. I., Sokolova Kseniia

Bacterial composition of activated sludge: identification and visualization

Summary

The objective of this work is to describe the capabilities of a method for visualizing activated sludge bacteria based on the information from an Internet resource for developing textbooks and/or manuals. Advanced methods of microscopy of the bacterial community are considered: optical light, scanning electron (SEM), transmission electron (TEM), confocal (CLSM), fluorescence hybridization in situ (FISH), new generation sequencing (NGS). On the basis of the methods presented, examples of bacterial flocculation of activated sludge with extracellular and reserve biopolymers are given. According to the highest citation frequency in professional reference books and literature, a sample of the most typical bacteria from the composition of floccules of activated sludge was compiled. Examples of visualization of four bacteria by SEM, TEM, KLSM, FISH methods are given: Bacillus subtilis (gram-positive, spore-forming, optionally aerobic), Nitrospira defluvii (gram-negative, aerobic, chemolithotrophic, nitrite-oxidizing), Candidatus «Accumulibacter phosphatis» (gram-negative, phosphate-accumulating), Candidatus «Microthrix parvicella» (gram-positive, filamentous, actinomycete). To date, the Internet resource contains a sufficient amount of reliable data on the visualization of activated sludge bacteria, their functionality and properties related to the key processes of biological treatment, classification or taxonomy, as well as on the methods of their microscopic study. The implementation of the capabilities for identifying the bacterial composition of activated sludge and the quantitative ratio of heterotrophic, autotrophic and phosphate-accumulating biomasses provides for setting and/or calibrating models of ASM series (for example, in GPS-X, BioWin, etc. software environment).

Key words

biological treatment , activated sludge , phosphate accumulating bacteria , filamentous bacteria , bacterial composition , extracellular biopolymers , visualization , identification , filamentous bacteria , autotrophic bacteria

bbk 000000

UDC 628.35

Stepanov S. V., Stepanov A. S., Gabidullina L. A., Dubov O. V.

Biological treatment of oil refinery wastewater  in a biosorption membrane reactor

Summary

The basic process and kinetic regularities of biomembrane and biosorption membrane treatment of fuel and lube refinery wastewater are presented. The enhancement of denitrification process is suggested by reducing the dissolved oxygen concentration in the circula­ting flow of activated sludge by vacuum treatment. Summarizing the results of operating a pilot vacuumizing unit the more efficient use of biosorption membrane technology compared to the biomembrane method is shown. Single dosing of 1 g of powdered activated carbon per 1 liter of mixed liquor provided for reducing the mean monthly concentration of pollutants in permeate: in COD – from 68 to 49 mg/l; in BOD_full – from 6 to 3.5 mg/l; in oil products – from 0.65 to 0.21 mg/l. The kinetic constants of the processes of eliminating the basic pollutants in membrane and biosorption membrane reactors were determined. It was stated that the specific oxidation rate in biosorption membrane reactors exceeded the similar indicators of membrane bioreactors only for easily sorbed substances – oil products and organic pollutants evaluated in BOD_full. Vacuum treatment of circulating activated sludge during 5 minutes at minus 90 kPa pressure in a membrane bioreactor provided for 2-fold reduction of the dissolved oxygen concentration, improvement of the sedimentation properties of activated sludge (compared to the flow scheme without vacuum treatment) and the dissolved oxygen concentration less than 0.5 mg/l in the anoxic zone of the membrane bioreactor.

Key words

wastewater , nitrification , activated sludge , membrane bioreactor , denitrification , oil refinery , kinetic constant , activated carbon , biosorption membrane reactor

bbk 000000

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 BOD_full, 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 BOD_full, for nitrification and denitrification. The temperature constant value for aerobic heterotrophic conversion, for nitrification and denitrification processes has been found.

Key words

wastewater , biological treatment , membrane bioreactor , activated sludge , kinetic constants , dairy factory

bbk 000000

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 2)

Summary

The technology of biological treatment of dairy wastewater is described that provides for meeting the standard maximum permissible concentrations for fishery water bodies. The results of the experimental studies in a pilot membrane bioreactor with real wastewater of «Pestravskii» butter factory are presented. The main process and kinetic parameters of the biological wastewater treatment processes have been obtained that are needed for designing a membrane bioreactor with nitrification-denitrification that provides for meeting the standard maximum permissible concentrations for fishery water bodies or requirements to the effluents discharged into a public sewer. The maximum specific rate of diary wastewater pollutants oxidation V_max at 7 g/l activated sludge concentration and 20 °С temperature is 40 mg/(g·h), Michaelis constant K_m – 15 mg/l, inhibition coefficient of metabolism products  – 0.54 l/g, temperature constant X for aerobic heterotrophic conversion – 0.079 deg^–1. Compared to the traditional treatment facilities the use of biomembrane techno­logy at the wastewater biological treatment stage provides for 1.4–1.5 reducing the treatment time, reactor volume and footprint owing to the increase of the oxidation capacity of the aeration units by increasing the activated sludge concentration to 10 g/l; and ensuring almost complete removal of suspended solids by eliminating the tertiary treatment stage. Possible elimination of chemical flotation stage before biological treatment is shown that provides for reducing the expenditures for expensive chemicals and streamlining the process flow scheme.

Ключевые слова

wastewater , biological treatment , activated sludge , membrane bioreactor , kinetic constant , dairy factory

DOI 10.35776/VST.2021.09.06
UDC 628.355.1

Mashchenko Zinaida, Bakharev Vladimir, Egorova Yu. A., Nesterenko O. I., Русских Я. М.

Effect of benzylpenicillin sodium salt on the species composition of activated sludge biocenosis

Summary

The species composition of activated sludge depends on many abiotic and biotic factors. To date, there is a problem of the presence of trace pharmaceuticals in wastewater that negatively affect the organisms of activated sludge performing biological water treatment. Antibiotics are drugs that cause disturbances in the metabolism of activated sludge and lead to a decrease in the level of water treatment. These substances inhibit the survival and reproduction of some types of organisms, and also result in the development of resistance in bacteria. The results of studies on the effect of benzylpenicillin sodium salt on hydrobionts of activated sludge with single and repeated exposure within 72 hours are presented. The general properties of the sludge – color, smell, bulking, sedimentation – were estimated. To study the sludge biocenosis, we used the «crushed drop» method with a magnification of ×1000. While analyzing the microscopic slides, the number of hydrobionts of activated sludge and their general condition were taken into account. The following species were used as indicator organisms: naked amoeba Amoeba, testate Testacea, flagellate Flagellata, rotifers Rotaria, infusoria Vaginicola, Epistylis and Aspidisca, worms Nematoda and Oligоchaeta, tardigrades, filamentous bacteria. The obtained data testified to the satisfactory operation of the activated sludge under the experimental conditions. However, with repeated addition of benzylpenicillin sodium salt, the nitrification processes may deteriorate.

Key words

aeration tank , activated sludge , wastewater biological treatment , antibiotics , municipal wastewater treatment facilities , benzylpenicillin sodium salt , hydrobionts of activated sludge

DOI 10.35776/VST.2022.03.05
UDC 628.355

Kevbrina M. V., Gavrilov Dmitrii, Belov N. A., Agarev Anton

The effect of the operation of secondary settling tanks on the efficiency of biological removal of nitrogen through the example of Kuryanovskie wastewater treatment facilities

Summary

«Mosvodokanal» JSC conducted an industrial-scale experiment with the secondary settling tanks of the new section of the Kuryanovskie wastewater treatment facilities in Moscow in order to determine the effect of the operation of settling tanks on the efficiency of biological removal of nitrites. With an increase in the level of sludge stand in the secondary settling tanks, conditions arise in the sludge layer at the bottom of the settler for the anaerobic processes that cause the lysis of activated sludge cells. Under these conditions, a sufficient amount of organic matter is generated in the sludge layer, both residual, occluded on sludge flocks, and formed during the lysis of part of the cells, so that in the presence of nitrates, the process of incomplete denitrification starts with the formation of nitrites. The occurrence of anaerobic processes in the bottom sludge layer in the secondary settling tanks is also affected by the oxygen concentration in the mixed liquor entering the secondary settling tanks. The process parameters of the operation of the facilities that prevent a decrease in the quality of effluent are determined: regulating the operation of secondary settling tanks depending on the load and residence time of the sludge dry matter that prevents the sludge from long staying in the bottom layer, as well as maintaining a high oxygen concentration at the end part of the aeration tanks.

Key words

wastewater , biological treatment , sludge disposal truck , secondary settling tank , activated sludge , nitrite nitrogen

UDC 628.355.2:631.461.2
DOI 10.35776/VST.2024.10.05

Wang Weize, Makarova S. V.

Temperature effect on nitrification processes in activated sludge

Summary

Temperature has been an important factor affecting the efficiency of biological nitrogen removal by activated sludge at wastewater treatment facilities. A laboratory SBR reactor was used in the experiments; activated sludge for cultivation was obtained from aeration tanks of the municipal wastewater treatment facilities. The taxonomic composition of bacteria in activated sludge was determined by high throughput sequencing of the DNA section encoding 16S rRNA. The nitrification rate was determined at water temperatures of 1, 5, 8, 11, 17, 19 and 21°C. Nnitrifying bacteria Nitrosomonas spp. and Nitrospira spp. were found in activated sludge with the abundance of 0.07% and 0.34%, respectively. The maximum nitrification rate observed at 21 °C was 4.3 mg N–NO₃ per 1 g of ash-free substance of activated sludge per hour. The nitrification rate decreased with decreasing temperature and was 0.3 mg/(g·h) by N–NO₃ at 1°C. The results of the study can be used as a theoretical basis for optimizing the operation of the treatment facilities in areas with low temperatures to improve the efficiency of nitrogen removal from wastewater.

Key words

wastewater , nitrification , activated sludge , temperature , biological removal of nitrogen

bbk 000000

UDC 628.356.5

Kevbrina M. V., KOZLOV M. N., Dorofeev A. G.

Secondary settlers: comparison of the calculation methods in designing and analysis of the parameters of efficient operation of the facilities

Summary

The results of the comparison of methods of calculating secondary settlers through the example of a model wastewater treatment plant (domestic method according to SNiP 2.04.03-85, German method according to Germany Standard ATV-DVWK-A131E, American method based on mass flow theory) are presented. It is shown that the surface area of settlers calculated according to Standard ATV has higher values compared to the calculations according to SNiP 2.04.03-85 and American method. The values of the surface area of settling tanks calculated according to SNiP 2.04.03-85 and American method are very close. At the same time the SNiP method is much simpler and requires much less initial parameters than the American method. For the domestic practice of operating secondary settlers it is proposed to introduce a new parameter – «dry matter loading on the settler surface» taken from the mass flow theory. This indicator indicates how much dry matter of the mixed liquor from aeration tanks enters per unit surface of secondary settlers per hour and corresponds to the incoming mass flow. By varying the dry matter loading on the surface of secondary settlers it is possible to provide for the standard suspended solids concentration in effluent. Through the example of the operating 54 m diameter settlers the dependence of the clarification efficiency on this parameter is shown.

Key words

wastewater , biological treatment , sludge index , secondary settling tank , activated sludge , calculation method

bbk 000000

UDC 628.336.5

Nikolaev Yu. A., Kevbrina M. V., Dorofeev A. G., Vanyushina A. Ya., Agarev Anton

High technology of methane digestion of wastewater sludge with biomass recycling

Summary

The technology of methane digestion of wastewater sludge with biomass recycling developed at Mosvodokanal MPUE is presented. The technology advantages ensure reducing the dry weight of sludge compared to the traditional digestion due to deeper decomposition of ash-free matter, and saving the sludge transportation, dewatering and utilization costs. Introduction of the technology at large-scale facilities will provide for eliminating the problem of hydraulic overloading.

Key words

sludge , biogas , activated sludge , biomass recycling , methane digestion , thickening , specific resistance to filtration

UDC 628.355.3
DOI 10.35776/VST.2024.11.04

Mashchenko Zinaida, Русских Я. М., Egorova Yu. A., Nesterenko O. I.

Study of the effect of ampicillin on the functional state of activated sludge at multiple exposure

Summary

The widespread use of antibiotics in medicine and veterinary science results in an increase in their production, which contributes to the occurrence and accumulation of these drugs in the surrounding aquatic environment. Antibiotics, getting into wastewater, disturb the degradation of organic matter by microorganisms of activated sludge which results in a decrease in the functional state of activated sludge, and also contributes to the development of multiresistant strains of bacteria. In this regard, it is important to estimate the impact of antibiotics on the hydroecosystem of the treatment facilities. Estimation of the functional state of activated sludge of biological treatment facilities is possible using hydrobiological analysis. Hydrochemical indicators of activated sludge, quantitative calculation of activated sludge organisms provides for monitoring the state of the biological wastewater treatment process. The results of estimating the effect of ampicillin on the functional state of activated sludge at multiple exposure are presented. Activated sludge of the Samara wastewater treatment facilities was used as test organisms. The betalactam antibiotic ampicillin served as the material for the study. The antibiotic was added every 24 hours at a concentration of 100 mg per 1g of activated sludge. Incubation of activated sludge was carried out at a temperature of 25°C for 72 hours at continuous aeration. Samples of activated sludge without antibiotic addition served as a control. During the experiment, the hydrochemical characteristics and species composition of the activated sludge biocenosis were estimated. It was shown that ampicillin added multiple times, had a negative effect on the functional state of activated sludge aggravating the sedimentation properties and reducing the species diversity of activated sludge.

Key words

activated sludge , antibiotics , ampicillin , species composition of the activated sludge , general properties of activated sludge

DOI 10.35776/MNP.2020.01.03
UDC 628.355

Zalyotova N. A., Zalyotov S. V.

The study of the response of dehydrogenase activity
of sludge to a change in the process parameters of an aeration tank

Summary

The biological method of wastewater treatment is a comprehensive multicomponent process; the activities of the enzyme system being the key component of it. It is known that dehydrogenases have been one of the most important enzymes the ensure the biological process. The complicated mechanism of the action of enzymes has not been fully described so far; however, in the practice of monitoring biological treatment processes, an indicator of the dehydrogenase activity of sludge is used. The research results provided for supplementing the available information with actual data on the interdependence of the level of dehydrogenase activity of sludge and indicators of individual process parameters of biological treatment. It was shown that the mode of operation of aeration tanks (organic matter load on sludge, dose of activated sludge, etc.) and the values of the initial dehydrogenase activity and dehydrogenase activity of the same sludge sample with weakly concentrated solution (DASН2О) are interconnected and depend on the organic load on sludge. The results of the study can be used to control the biological process of wastewater treatment.

Key words

wastewater , biological treatment , aeration tank , activated sludge , active sludge dosage , dehydrogenase activity , organic matter load on sludge

bbk 000000

UDC 628.356.57.001.5

SHVETSOV V. N., MOROZOVA K. M., Smirnova I. I., Semenov Mikhail, Lezhnev M. L., Ryzhakov G. G., Gubaydullin T. M.

The Use of Bioblocks at Wastewater Treatment Facilities

Summary

Results of the laboratory study of an aeration tank operation for the purpose of technological comparison of two new modified bioblocks, BBZ-45P-14 and BBZ-65P-10, having the similar surface structure but different geometric parameters are presented. It is shown that these bioblocks can be used successfully in aeration tanks for immobilization of microorganisms of activated sludge. The tests of loading material samples have been carried out at biomass density in bioblocks of 0,3–0,36 kg/kg, at equivalent concentration of sludge in the system – 2,3 g/l. The bioblock BBZ-65P-10 is used preferably in aeration tanks, BBZ-45P-14 – in aeration tanks with low load on activated sludge, blocks of aftertreatment for additional clarification of water treated biologically and in biofilters for build-up of biological film. The comparison of results of tests on rate of activated sludge adhesion obtained with new types of bioblocks and BBZ-65 tested earlier makes it possible to conclude that the adhesion process goes off more intensively on rougher surfaces of modified models of bioblocks.

Key words

wastewater , biological treatment , biofilter , bioblock , aeration tank , secondary settling tank , adhesion , activated sludge

UDC 6285.355
DOI 10.35776/VST.2024.06.08

Latypova Tat’iana, Zentsov Viacheslav, Lapshakova Irina, Naumov Ivan, Frolov Boris

Study of the imact of chemical plant wastewater on the adaptation of activated sludge at the municipal wastewater treatment facilities

Summary

The impact of diluted wastewater of a chemical plant on the biocenosis of microorganisms in activated sludge at the municipal wastewater treatment facilities is considered. In the course of studies, wastewater of Khimvolokno enterprise in Blagoveshchensk with known pollution concentrations was taken as a basis. Experiments were conducted to examine the impact of industrial wastewater on biological treatment, namely, in what proportions blending this wastewater with no harmful effect on the biocenosis of microorganisms is possible. Observations of the activated sludge show that at 1:50 dilution supplying wastewater with this ratio provides for slower inhibition of microorganisms than when supplying wastewater with a dilution of 1:10, 1:20, 1:30, 1:40. This wastewater can supplied to treatment facilities with gradual long-term adaptation of the biocenosis to it.

Key words

activated sludge , wastewater biological treatment , biocenosis , chemical plant

bbk 000000

UDC 628.336.3

Kofman V. Ya.

Wastewater sludge handling in Europe(review of foreign publications)

Summary

A review of foreign literature on wastewater sludge treatment and utilization is presented. Regulatory requirements to wastewater treatment facilities operation in EC countries are given. Total characteristic of wastewater sludge is given together with sludge treatment methods (chemical stabilization, anaerobic and aerobic digestion, dewatering, thermal drying etc.), ways of utilization (storage, incineration, agricultural use, pyrolysis, gasification, wet oxidation etc.)

Key words

sludge , activated sludge , sewerage treatment facilities , heavy metals , organic substances , sludge utilization

bbk 000000

UDC 628.35:661.5.63

KOZLOV M. N., Moyzhes O. V., Nikolaev Yu. A., GRACHEV V. A., Kevbrina M. V., Dorofeev A. G., Aseyeva V. G.

M-Defanox – multisludge system of nutrient removal

Summary

M-Defanox new technology was developed for the treatment of municipal wastewater low in organics. The method is based on the use of three sludge types and dephosphorization under anoxic conditions. The technology provides for the efficient utilization of organics in biological treatment process and ensures 99% nitrogen removal, 80% phosphorus elimination, 80% COD removal and 95% BOD removal.

Key words

wastewater , biological treatment , nitrogen , phosphorous , activated sludge , biogenic elements

DOI 10.35776/VST.2022.12.05
UDC 628.35

Andreev Sergei, Stepanov S. V., Strelkov A. K.

Mathematical modeling of the wastewater biological treatment process in a plug flow aeration tank

Summary

The results of theoretical studies of the kinetics of the processes of biochemical oxidation of organic wastewater pollution by activated sludge microorganisms are presented. It is shown that the value of the average effective value of the specific rate of organic wastewater pollution oxidation by the activated sludge in a plug flow aeration tank can be determined using the theorem on the average value of the continuous function f(L) integrated in a certain range of its variable from L_н to L_к. By integrating the Michaelis–Menten equation, a mathematical model was obtained based on the fundamental regularities of enzymatic kinetics that describes the process of biological oxidation of organic pollutants in a plug flow aeration tank. The use of the proposed equations will provide for determining the average effective values ​​of the specific oxidation rates of various organic pollutants (BOD, oil products, surfactants, phenols, etc.), the estimated duration of aerobic processes; and thereby, optimizing the design and operation of biological wastewater treatment facilities in plug flow aeration tanks.

Key words

activated sludge , complete-mix activated sludge system , specific oxidation rate , biochemical oxidation , enzyme kinetics , plug flow aeration tank

DOI 10.35776/MNP.2020.07.07
UDC 628.356.5

Kevbrina M. V., Novikov S. N.

Method of analyzing the operation of secondary settlers with the purpose of the optimization (for the discussion)

Summary

According to the results of laboratory tests on determining the sedimentation rate of sludge mixture particles in aeration tanks of wastewater treatment facilities, the curves of the gravitational mass flow, calculated in two ways, were plotted. Through the example of sludge mixture in the experimental aeration tank at the Lyuberetskie wastewater treatment facilities in Moscow, a method for analyzing the operation of secondary settlers State Point Analysis, based on the theory of mass flows, is presented. This method provides for estimating the operation of secondary settlers with the purpose of making an operational decision to optimize their operation. «Dry matter load on the surface of secondary settlers» indicator is proposed to be introduced into the practice of operating secondary settlers as another tool for the control of their operation. This parameter shows the amount of dry matter of the sludge mixture in the aeration tanks that is supplied per unit surface of the secondary settlers per hour, and corresponds to the incoming mass flow. The dependence of the concentration of suspended solids in the effluent on the dry matter load and sludge index is given. By changing the dry matter load on the surface of the secondary settlers the standard quality of effluent in terms of suspended solids can be ensured.

Key words

wastewater , biological treatment , sludge index , aeration tank , secondary settling tank , activated sludge

bbk 000000

UDC 628.17.001.4

Lominoga O. A., Agapov D. V., Kell L. S.

Minimizing the recovery of phosphorus-containing pollutants in the process of wastewater sludge treatment

Summary

To improve the Baltic Sea basin the problem of reducing the concentration of nutrients, phosphorus in particular, in the effluents must be solved. No less important is to prevent bound phosphorus recovery in the subsequent process of activated sludge dewatering. It is shown that minimizing phosphorus recovery during sludge dewatering and preventing secondary pollution of effluents can be ensured by separate thickening of activated sludge and raw sludge; as well as by minimizing the retention time of activated sludge and raw sludge mixture before mechanical dewatering.

Kye words

biological treatment , dephosphatization , activated sludge , eutrophication , secondary pollution , sludge dewatering

UDC 628.355:004.942
DOI 10.35776/VST.2023.12.06

Yermolin Yu. A.

On mathematical modeling a biological wastewater treatment process (for discussion)

Summary

The process of interaction between an organic pollutant and activated sludge underlies the biological wastewater treatment technologies at the wastewater treatment facilities. A mathematical dynamic model of such a process is proposed that is a system of two nonlinear differential equations that quantitatively show how the treatment process proceeds over time. While developing a model, considerations and arguments of a physical nature are given in detail for the inclusion of each member in it. The conditions for using a palliative version of the developed model, i.e., its linearized version, are discussed. As a result of calculations made using the model, for some situations analytical expressions were obtained that connected the parameters of the treatment process with the characteristics of the organic pollutant and activated sludge.

Key words

wastewater treatment , activated sludge , organic pollutant , dynamic mathematical model , linearization , analytical results

UDC 628.38:628.336.3
DOI 10.35776/VST.2024.09.08

Strelkov A. K., Teplykh Svetlana, Teplykh Evgenii, Porshina Elizaveta

Justification for the use of sludge of biologically treated wastewater in the production of ceramic materials

Summary

Pollution in industrial wastewater comprises the scraps of processed raw materials and chemicals used in the treatment process. The conditions of the generation and properties of sludge of wastewater biological treatment and of matured sludge are considered. The properties of municipal wastewater sludge and main ways of utilization are given, as well as theoretical justification for the use of matured sludge from biological wastewater treatment facilities in the production of ceramic materials. The following characteristics of municipal wastewater sludge are presented: fractional makeup, dynamic pattern of the mass of various sludge fractions in the process of thermal processing, chemical composition.

Key words

activated sludge , primary settler , wastewater sludges , sludge utilization , solid part of sludge , composition of sludge dry matter , production of ceramic materials , digested mixture