DOI: https://doi.org/10.15802/stp2020/218302

### COMPUTER SIMULATION OF BIOLOGICAL WASTEWATER TREATMENT PROCESSES IN AEROTANKS WITH PLATES

M. M. Biliaiev, M. V. Lemesh, V. V. Biliaeva, P. B. Mashykhina, Z. M. Yakubovska

#### Abstract

Purpose. Efficiency determination of the aeration tank at the stage of design or reconstruction of bioreactors in which biological wastewater treatment is carried out requires the use of special mathematical models and calculation methods. The main purpose of the article is to develop CFD models for evaluating the operation efficiency of aeration tanks. Methodology. A numerical model has been developed for the computer calculation of the biological wastewater treatment process in aerotanks, taking into account hydrodynamics. The model is based on two-level mass conservation equations for the substrate and activated sludge and the velocity potential equation. The process of biological transformation of the substrate is calculated based on the Monod model. For the numerical integration of the mass transfer equations of activated sludge and substrate, the alternating-triangular difference splitting scheme is used. In this case, the basic equations are divided into two equations of a more simplified form. For the numerical integration of the equations for the velocity potential, it is split into two one-dimensional equations. Further, each equation is solved according to explicit scheme. For the numerical integration of equations that describe the process of substrate transformation based on the Monod model, the Euler method is used. Findings. The software implementation of the constructed numerical model has been carried out. The results of a computational experiment on the study of the wastewater treatment process in an aeration tank with plates are presented. This leads to the conclusion that the quality control of wastewater treatment in aeration tanks is possible with the help of plates. Originality. A multivariate CFD model has been developed, which makes it possible to quickly assess the efficiency of the aeration tank. A feature of the model is the ability to evaluate the operation of the aeration tank, taking into account its geometric shape and location of additional plates in the construction. Practical value. The constructed numerical model can be used during calculations in the case of designing aeration tanks, or in determining the efficiency of wastewater treatment under new operating conditions.

#### Keywords

water purification; numerical modeling; aerotank; model Mono; CFD models; biological cleaning; wastewater; ac-tivated sludge; concentration of pollutants

#### Full Text:

PDF translation (Русский) HTML

#### References

Biliaiev, N. N., & Nagornaya, E. K. (2012). Matematicheskoye modelirovaniye massoperenosa v otstoynikakh sistem vodootvedeniya: monografiya. Dnepropetrovsk: Novaya ideologiya. (in Russian)

Biliaiev, N. N., & Kozachina, V. A. (2015). Modelirovaniye massoperenosa v gorizontalnykh otstoynikakh: monografiya. Dnepropetrovsk: Aktsent PP. (in Russian)

Vasylenko, O. A., Hrabovskyi, P. O., Larkina, H. M., Polishchuk, O. V., & Prohulnyi, V. Y. (2010). Rekonstruktsiia i intensyfikatsiia sporud vodopostachannia ta vodovidvedennia: navchalnyi posibnyk. Kyiv: IVNVKP «Ukrheliotek». (in Ukrainian)

Karelin, Ya. A., Zhukov, D. D., Zhurov, V. N., & Repin, B. N. (1973). Ochistka proizvodstvennyh stochnyh vod v aerotenkah. Moscow: Stroiyzdat. (in Russian)

Laskov, Yu. M., Voronov, Yu. V., & Kalicun, V. I. (1981). Primery raschetov kanalizacionnyh sooruzhenij. Moscow: Vysshaya Shkola. (in Russian)

Oleynik, A. Y., & Airapetyan, T. S. (2015). The modeling of the clearance of waste waters from organic pollutions in bioreactors-aerotanks with suspended (free flow) and fixed biocenoses. Reports of the National Academy of Sciences of Ukraine, 5, 55-60. DOI: https://doi.org/10.15407/dopovidi2015.05.055 (in Ukrainian)

Alharbi, A. O. M. (2016). The biological treatment of wastewater: mathematical models. Bulletin of the Australian Mathematical Society, 94(2), 347-348. DOI: https://doi.org/10.1017/s0004972716000411 (in English)

Amaral, A., Gillot, S., Garrido-Baserba, M., Filali, A., Karpinska, A. M., Plósz, B. G., … & Rosso, D. (2019). Modelling gas-liquid mass transfer in wastewater treatment: when current knowledge needs to encounter engineering practice and vice-versa. Water Science & Technology, 80(4), 607-619. DOI: https://doi.org/10.2166/wst.2019.253 (in English)

Babaei, A., Azadi, R., Jaafarzadeh, N., & Alavi, N. (2013). Application and Kinetic Evaluation of upflow Anaerobic biofilm Reactor for Nitrogen Removal from Wastewater. Iranian Journal of Environmental Health Science and Engineering, 10(1), 1-8. DOI: https://doi.org/10.1186/1735-2746-10-20 (in English)

Bomba, A., Klymiuk, Y., Prysiazhniuk, I., Prysiazhniuk, O., & Safonyk, A. (2016). Mathematical modeling of wastewater treatment from multicomponent pollution by through microporous filling. AIP Conference Proceedings, 1773, 040003-1-040003-11. DOI: https://doi.org/10.1063/1.4964966 (in English)

Dapelo, D., & Bridgeman, G. (2020). A CFD strategy to retrofit an anaerobic digester to improve mixing performance in wastewater treatment. Water Science & Technology, 81(8), 1646-1657. DOI: https://doi.org/10.2166/wst.2020.086 (in English)

Gao, H., & Stenstrom, M. K. (2019). Development and applications in CFD modeling for secondary settling tanks over the last three decades: A review. Water Environment Research, 92(6), 796-820 DOI: https://doi.org/10.1002/wer.1279 (in English)

Gao, H., & Stenstrom, M. K. (2020). Influence of Model Parameters and Inlet Turbulence Boundary Specification Methods in Secondary Settling Tanks: Computational Fluid Dynamics Study. Journal of Environmental Engineering, 146(5), 04020028-1-04020028-12. DOI: https://doi.org/10.1061/(ASCE)EE.1943-7870.0001689 (in English)

Gao, H., & Stenstrom, M. K. (2020). Computational Fluid Dynamics Analysis for Improving Secondary Settling Tank Performance. Conference: World Environmental and Water Resources Congress 2020, 212-224. DOI: https://doi.org/10.1061/9780784482988.021 (in English)

Griborio, A. (2004). Secondary Clarifier Modeling: A Multi-Process Approach. Dissertation and Theses. USA, University of New Orleans Publ. (in English)

Mocanu, C. R., & Mihaillescu, R. (2012). Numerical Simulation Wastewater Treatment Aeration Processes. U. P. B. Sci. Bull., Series D, 74(2), 191-198. (in English)

Pereda, M., & Zamarreno, J. M. (2011). Agent–based modeling of an activated sludge process in batch reactor. 19th Mediterrian Conference on Control and Automation Aquis, 1128-1133. DOI: https://doi.org/10.1109/med.2011.5983027 (in English)

#### GOST Style Citations

1. Беляев Н. Н., Нагорная Е. К. Математическое моделирование массопереноса в отстойниках систем водоотведения : монография. Днепропетровск : Новая идеология, 2012. 112 с.
2. Беляев Н. Н., Козачина В. А. Математическое моделирование массопереноса в горизонтальных отстойниках : монография. Днепропетровск : Акцент ПП, 2015. 115 с.
3. Василенко О. А., Грабовський П. О., Ларкіна Г. М., Поліщук О. В., Прогульний В. Й. Реконструкція і інтенсифікація споруд водопостачання та водовідведення : навч. посіб. Київ : ІВНВКП «Укргеліотек», 2010. 272 с.
4. Карелин Я. А., Жуков Д. Д., Журов В. Н., Репин Б. Н. Очистка производственных сточных вод в аеротенках. Москва : Стройиздат, 1973, 223 с.
5. Ласков Ю. М., Воронов Ю. В., Калицун В. И. Примеры расчетов канализационных сооружений. Москва : Высшая школа, 1981. 237 с.
6. Олійник О. Я, Айрапетян Т. С. Моделювання очисних стічних вод від органічних забруднень в біореакторах-аеротенках зі зваженим (вільно плаваючим) і закріпленим біоценозом. Доповідь НАН України. 2015. № 5. С. 55–60. DOI: https://doi.org/10.15407/dopovidi2015.05.055
7. Alharbi A. O. M. The biological treatment of wastewater : mathematical models. Bulletin of the Australian Mathematical Society. 2016. Vol. 94. Іss. 2. P. 347–348. DOI: https://doi.org/10.1017/S0004972716000411
8. Amaral A., Gillot S., Garrido-Baserba M., Filali A., Karpinska A. M., Plósz B. G., … Rosso D. Modelling gas-liquid mass transfer in wastewater treatment : when current knowledge needs to encounter engineering practice and vice-versa. Water Science & Technology. 2019. Vol. 80. Iss. 4. P. 607–619. DOI: https://doi.org/10.2166/wst.2019.253
9. Babaei A., Azadi R., Jaafarzadeh N., Alavi N. Application and Kinetic Evaluation of upflow Anaerobic biofilm Reactor for Nitrogen Removal from Wastewater. Iranian Journal of Environmental Health Science and Engineering. 2013. Vol. 10. Iss. 1. P. 1–8. DOI: https://doi.org/10.1186/1735-2746-10-20
10. Bomba A., Klymiuk Y., Prysiazhniuk I., Prysiazhniuk O., Safonyk A. Mathematical modeling of wastewater treatment from multicomponent pollution by through microporous filling. AIP Conference Proceedings. 2016. Vol. 1773. P. 040003-1–040003-11. DOI: https://doi.org/10.1063/1.4964966
11. Dapelo D., Bridgeman G. A CFD strategy to retrofit an anaerobic digester to improve mixing performance in wastewater treatment. Water Science & Technology. 2020. Vol. 81. Iss. 8. P. 1646–1657. DOI: https://doi.org/10.2166/wst.2020.086
12. Gao H., Stenstrom M. K. Development and applications in CFD modeling for secondary settling tanks over the last three decades : A review. Water Environment Research. 2019. Vol. 92. Iss. 6. P. 796–820. DOI: https://doi.org/10.1002/wer.1279
13. Gao H., Stenstrom M. K. Influence of Model Parameters and Inlet Turbulence Boundary Specification Methods in Secondary Settling Tanks : Computational Fluid Dynamics Study. Journal of Environmental Engineering. 2020. Vol. 146. Iss. 5. P. 04020028-1–04020028-12.
DOI: https://doi.org/10.1061/(ASCE)EE.1943-7870.0001689
14. Gao H., Stenstrom M. K. Computational Fluid Dynamics Analysis for Improving Secondary Settling Tank Performance. Conference : World Environmental and Water Resources Congress 2020. 2020. P. 212–224. DOI: https://doi.org/10.1061/9780784482988.021
15. Griborio A. Secondary Clarifier Modeling : A Multi-Process Approach. Dissertation and Theses. University of New Orleans : USA, 2004. 440 p.
16. Mocanu C. R., Mihaillescu R. Numerical Simulation Wastewater Treatment Aeration Processes. U. P. B. Sci. Bull., Series D. 2012. Vol. 74. Iss. 2. P. 191–198.
17. Pereda M., Zamarreno J. M. Agent – based modeling of an activated sludge process in batch reactor. 19th Mediterrian Conference on Control and Automation Aquis. 2011. P. 1128–1133. DOI: https://doi.org/10.1109/med.2011.5983027