CFD Simulation of Aeration and Mixing Processes in a Full-Scale Oxidation Ditch

Höhne, Thomas; Mamedov, Tural

doi:10.3390/en13071633

Cited by 11 publications

(7 citation statements)

References 12 publications

(28 reference statements)

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“…The turbulence intensity during aeration ranged from 1.8 to 9.28%. These values are comparable to the averaged values of turbulence degree obtained by Liu et al [29]. The distribution of kinetic energy in the considered diffusers is also similar, however, there are differences in the turbulence intensity in different areas of the reservoir.…”

Section: Resultssupporting

confidence: 89%

“…CFD modeling also allows for quick elimination of incorrect design assumptions and enables analysis of the proposed solutions not only on a laboratory scale but also on a technical scale. From the economic point of view, the use of computer simulations should be encouraged, as it allows the design and initial testing of a new structure virtually -through numerical calculations, eliminating the need to build many prototypes of the modeled device [29][30][31][32][33].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Modeling and optimizations of mixing and aeration processes in bioreactors with activated sludge

Zaburko

Łagód

Widomski

et al. 2021

J. Phys.: Conf. Ser.

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Mixing aimed at homogenization of the volume of bioreactors with the activated sludge is of great importance for the proper course of the wastewater treatment process. It affects both the efficiency of pollutants removal and the properties of the activated sludge related to its sedimentation. The mixing process in bioreactors can be carried out in different ways. In batch bioreactors in the aeration phase or flow bioreactors in aerobic chambers, mixing is carried out through aeration systems. These systems should aerate the activated sludge flocs for efficient biological treating of wastewater, as well as effectively homogenize the volume of the bioreactor. Hence, it is important to choose such a design of the aeration system and its operation settings that provide the amount of air ensuring the exact amount of oxygen for the implementation of technological processes, counteract sedimentation of sludge at the bottom of the reactor, are reliable as well as economical in operation (demand of electric energy). The paper presents the model studies aimed at optimization of the design and settings of aeration and mixing systems used in active sludge bioreactors.

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Section: Resultssupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Modeling and optimizations of mixing and aeration processes in bioreactors with activated sludge

Zaburko

Łagód

Widomski

et al. 2021

J. Phys.: Conf. Ser.

View full text Add to dashboard Cite

show abstract

“…The multi-fluid model is the most commonly used multi-phase flow model for the large bubble population in an aeration tank (Höhne and Mamedov, 2020;Hreiz et al, 2019;Karpinska and Bridgeman, 2016;Karpinska and Bridgeman, 2018). It solves the continuity and momentum equations of each phase (Ranade, 2002).…”

Section: Two Phase Flowmentioning

confidence: 99%

Computational fluid dynamics simulation of two-phase flow and dissolved oxygen in a wastewater treatment oxidation ditch

Matko

Chew

Wenk

et al. 2021

Process Safety and Environmental Protection

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This paper presents a computational fluid dynamics (CFD) model of an aerated wastewater treatment oxidation ditch, taking into account gas-liquid flow, mass transfer and dissolved oxygen. This innovative study contributes to knowledge as it considers the effect of bubble size distribution (BSD) and biochemical oxygen demand (BOD) distribution on the dissolved oxygen (DO) distribution. Species transport modelling predicts the DO and BOD distribution. De-oxygenation of local dissolved oxygen by BOD is modelled by an oxygen sink that depends on the local BOD concentration. Bubble coalescence and breakup models predict the BSD. The behaviour of the ditch is non-ideal, which is indicated by the residence time distribution (RTD) and the heterogeneous flow pattern and DO distribution. The parameters with the greatest influence on the dissolved oxygen are the BOD and bubble size. There is good agreement with the observed flow patterns and the measurements of mean DO. This study identifies that the BOD distribution and the BSD are important parameters for predicting the dissolved oxygen distribution and are also current gaps in the published research.

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“…United Nations (UN) aims to ensure availability and sustainability management of water by encouraging water treatment programmes. The core and fundamental component of wastewater treatment plants (WWTPs) is biological wastewater treatment, which is used to extract biodegradable organic waste and suspended solid from raw wastewater [1]. Regarding energy consumption, bioreactor zones can consume up to 70% of the overall energy needed for the whole treatment process [2].…”

Section: Introductionmentioning

confidence: 99%

Computational fluid dynamics-based design of anoxic bioreactor zone in wastewater treatment plant

Amin¹,

Elsakka²,

Oterkus³

et al. 2022

Desalination and Water Treatment

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Hydrodynamics-based design of an anoxic bioreactor tank is one of the serious challenges in wastewater industry. Poor fluid flow may cause settlement and therefore reduce the biological performance of a bioreactor. Whilst, a successful bioreactor design can facilitate the enhancement of biological process efficiency and reduction of energy consumption so that the investment and operation cost can be kept as low as possible. In the present study, three-dimensional computational fluid dynamics models for three common full-scale bioreactor configurations were simulated using a single-phase flow model and the standard two-equation SST k-ε turbulence model. The main objective of this numerical study is to investigate the effect of bioreactor geometry on the hydrodynamics performance of the flow field. Four submerged impellers were modelled for each tank geometry and three thrust scenarios were considered in order to evaluate the effect of changing impeller thrust on the flow velocity distribution inside each tank. The results show that the orbal bioreactor geometry has better performance in driving the flow field with more uniform flow patterns than other bioreactor configurations. The minimum flow velocity required was achieved in orbal tank to maintain the micro-organism particles suspended in the wastewater media at certain mixing power.

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CFD Simulation of Aeration and Mixing Processes in a Full-Scale Oxidation Ditch

Cited by 11 publications

References 12 publications

Modeling and optimizations of mixing and aeration processes in bioreactors with activated sludge

Modeling and optimizations of mixing and aeration processes in bioreactors with activated sludge

Computational fluid dynamics simulation of two-phase flow and dissolved oxygen in a wastewater treatment oxidation ditch

Computational fluid dynamics-based design of anoxic bioreactor zone in wastewater treatment plant

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