Keywords: wastewater treatment, oxygen regime, aerotank mixer, active sludge, fixed biomass (biofilm), concentration of pollutants and oxygen, initial parameters, calculation, evaluation, analysis


The most widely used biological methods of urban wastewater treatment, based on the use of the ability of microorganisms to oxidize organic pollution. The process of biological purification from pollutants occurs in aerotanks at direct contact of sewage with microorganisms of active sludge in the presence of an appropriate amount of dissolved oxygen. The effectiveness of removing contaminants in aerotanks can be greatly enhanced by the installation of additional loading (nets, nozzles, etc.), on the surface of which a biofilm with a high concentration of microorganisms is formed. In this case, the immobilized biocenose works simultaneously with the weighted volume of the building (active sludge). To organize an effective process of oxidation to aeration systems, it is necessary to provide such an oxygen regime in a reactor, in which the rate of biological purification should not be limited by the amount of oxygen contained in the reactor.

Examples of calculation of parameters of oxygen regime in aerotank-mixers with weighted and fixed biocenosis are given, an estimation of influence of various parameters is carried out. Considered the most expedient from a practical point of view technological scheme of wastewater treatment. The aerotank-mixer consists of two parts (reactor 1 and 2), while in the reactor 1, the removal of organic contaminants occurs due to weighted biocenosis (active sludge), that is, as in the usual aerotank-mixers, and in rector 2, the removal of organic contamination occurs at the expense of enshrined in the loading biocenose (biofilm).

The proposed method for calculating the oxygen regime in aerotank-mixers with fixed and weighted biocenosis. It is believed that the oxidation of pollution by an active sludge occurs in a zero-order reaction, and a biofilm is a reaction of the first order. The influence of limiting factors on concentration of dissolved oxygen and organic pollutants is estimated. The practical recommendations for its use are given, which allow to substantiate the most expedient mode of oxygen maintenance of biological purification processes in structures of advanced design and to evaluate the efficiency of application of additional loading with high concentrations of microorganisms on its surface.

Author Biographies

A. Oleynik, Institute of Hydromechanics of the NAS of Ukraine
Corresponding Member of the National Academy of Sciences of Ukraine, Doctor of Technical Sciences, Professor head of the department of applied hydrodynamics
T. Airapetian, O.M. Beketov National University of Urban Economy in Kharkiv

Ph.D., Associate Professor, Associate Professor of Department


DBN V.2.5-75-2013. (2013). Sewerage.Outdoor networks and structures.The main provisions of the design, Kyiv, Ministry of Regional Development of Ukraine, 128.

Grytsina, O.О., Yesin, M.A., Zhukova, al. (2018). Investigation of wastewater treatment processes from biogenic elements and utilization of sewage power potential. Monography. Rivne, NUVGP, 267.

Vasilenko, A., Grabovsky, P., Larkina, G. (2010).Reconstruction and intensification of water supply and sewage facilities: Textbook. Kyiv, IVNVKP "Ukrelyotokh", 272.

Kulikov, N. I., Zubov, M. G., Kulikova, E. N. etal (2013). Biological sewage treatment (theory and practice). - Sochi: Doria Publishing House, 289.

Oleynik, A.Ya., Airapetian, T.S. (2015). Modelling of the waste water treatment from the organic contaminations in the bioreactors-aerotanks with suspended (free flowing) and fixed biocenosis.. Reports of the National Academy of Sciences of Ukraine, 5, 55-59.

Gebara, F. (1999). Activated sludge biofilm waste water treatment system Water Research. – Oxford: Pergamon Press, 13, 1 , 230-238.

Zhmur, N.S. (2003). Technological and biochemical processes of sewage treatment in constructions with aerotanks. - M .: AQUAROS, 512.

Svyatenko, A., Dyadenko, N., Nechiporenko-Shabunina, T. (2011). Research of change of efficiency of sewage treatment naerotanks under the influence of different factors. Ecological safety, 1, 64–66.

Henze, M., Van Loosdrecht, M., Ekama, G., Brdjanovic, D. (2008). Biological Wastewater Treatment. IwaPublishing, London, 511.

Olga Kolpakova (2015). Theoretical studies and calculations of waste water treatment in trickling biofilters MOTROL. Commission of motorization and energetics in agriculture: Polish Academy of sciences, Lublin-Rzeszow, 17, 8, 165-173.

Wanner, O., Ebert, N.I., Rittman, B.E. (2006). Matematical modeling of biofilms. Scientific and Technical report, 18, 208.

Airapetian, T.S., Telima, S.V., Oleynik, A.Ya. (2017). Modeling of oxygen regime in aerotanks bioreactors in the treatment of sewage from organic pollutants. Reports of the National Academy of Sciences of Ukraine, 6, 21-27.

Oleynik, A.Ya., Airapetian, T.S. (2016). Modelling and computation of the oxygen regime while extracting the organic contaminants in ideal mix aeration tank with suspended and fixed biocenose. Problems of water supply, drainage and hydraulics, 27, 269-279.

Henze, M., Harremoës, P., laCourJansen, J., Arvin, E. (2002). Waste water Treatment: Biological and Chemical Processes. 3rd ed. – Berlin, Springer, 430.

Oleynik, A.Ya., Airapetian, T.S. (2018). Calculation of oxygen regime in the biological treatment of sewage aerotanks-mixerswithfixedan suspended biocenose. Scientific Bulletinof Construction. - Kharkiv: KhNUBA, KOTV ABU, 98, 4, 187 - 191.

Oleynik, A.Ya., Airapetian, T.S. (2015). Theory and calculations of biological treatment of waste water in aerotanks with weighted (freelyfloating) and attachedtoadditionaldevices biocenose. Applied hydromechanics, 17 (89), 3, 35-43.

Abbassi, B., Dullstein, S., Rabiger, N. (2000). Minimization of excess sludge production by increase of oxygen concentration in activated sludge. Еxperimental and theoretical approach. Wat. Res., 34, 1, 139-146.

Evilevich, MA, Naumov, A.V., Blokhin, V.E., Shvitev, A.V. (1978). Mathematical Study of the Process of Biological Purificationon Flakes of Active Sludge, Water Resources, 1, 143-151.

Oleynik, A.Ya., Kolpakova, O.A. (2014). Modeling and calculations of biological wastewater treatment atdrip biofilters. Ecological safety and nature management, 16, 68-86.

Smith, D.P. (1995). Oxygen flux limitation in aerobic fixed-film biotreatment of a bazardous landfill leachate. Journal of Harardous Materials, 44, 77-91.

How to Cite