scholarly journals Simulation of Biological Wastewater Treatment in Aerotanks with Moving Biocenosis

2021 ◽  
pp. 15-24
Author(s):  
M. M. Biliaiev ◽  
M. V. Lemesh ◽  
V. O. Zadoia ◽  
P. B. Mashykhina ◽  
L. H. Tatarko ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Numerical Model ◽  
Activated Sludge ◽  
Water Purification ◽  
Operating Conditions ◽  
Finite Difference Schemes ◽  
Transfer Model ◽  
Aeration Tank ◽  
Biological Wastewater Treatment ◽  
Biological Water

Purpose. The main purpose of the article is to develop a numerical model for the analysis of the process of biological wastewater treatment in a reactor with a mobile biocenosis. Methodology. For mathematical modeling of the process of biological wastewater treatment in a reactor with a moving biocenosis, a hydrodynamic model of a non-viscous vortex-free flow is used. We calculated the boundary conditions for the modeling equation on the surfaces of the bioreactor, solid walls, and the upper surface; at the inlet boundary; at the outlet boundary from the building. To calculate the process of movement of activated sludge and substrate in the bioreactor, a mass transfer model is used, which takes into account the convective-diffusion movement of the substrate and activated sludge. The process of biological water purification in that part of the bioreactor where there are no mobile biocenosis carriers will be calculated based on the Monod model. The process of biological water purification in the part of the bioreactor where there are mobile carriers is calculated on the basis of an empirical model in three stages. The first stage is determined using the Harremoes model. At the second stage, the rate of substrate «consumption» in the biofilm is calculated. At the third stage, the change in the substrate concentration in the zone where the biocenosis carriers are located is determined due to convective movement, substrate diffusion in the flow and its destruction in the biofilm on the carriers. The chaotic motion of biocenosis carriers in the reactor is modeled based on the parabolic diffusion equation. Finite-difference schemes are used for numerical integration of modeling equations. Findings. The software implementation of the constructed numerical model is carried out. A computational experiment to determine the efficiency of biological wastewater treatment in different parts of the bioreactor was conducted. Originality. An effective multifactorial numerical model has been created, which allows quick analysis of the efficiency of biological wastewater treatment in an aeration tank with mobile biocenosis carriers. Practical value. The created two-dimensional numerical model can be used for serial calculations at the stage of designing biological wastewater treatment systems and analysis of the efficiency of bioreactors under different operating conditions.

scholarly journals MODELING OF WASTEWATER TREATMENT

2021 ◽  
Author(s):  
Yu.S. Chirikanova ◽  
Keyword(s):  
Mathematical Modeling ◽  
Mathematical Model ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Water Purification ◽  
Software Package ◽  
Biological Treatment ◽  
Aeration Tank ◽  
Biological Wastewater Treatment ◽  
Biological Treatment System

The paper deals with the problem of mathematical modeling of biological wastewater treatment. The peculiarity of the biological treatment system is that a block with activated sludge, called an aeration tank, is used for water purification. To describe the process of biological wastewater treatment in aeration tanksa mathematical model developed in the GPS-X software package is proposed.

scholarly journals 3D MODELING OF BIOLOGICAL WASTEWATER TREATMENT IN AERATION TANK

2021 ◽  
pp. 5-14
Author(s):  
M. M. Biliaiev ◽  
M. V. Lemesh ◽  
O. Y. Gunko ◽  
V. O. Zadoia ◽  
P. B. Mashykhina ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Velocity Potential ◽  
Convective Diffusion ◽  
Three Dimensional ◽  
Aeration Tank ◽  
Biological Wastewater Treatment ◽  
Cfd Model ◽  
Diffusion Transfer ◽  
Dimensional Equation

Purpose. The main purpose of the article is to develop a 3D CFD model for modeling the process of biological wastewater treatment in an aeration tank. Methodology. For mathematical modeling of the process of biological wastewater treatment in the reactor, taking into account the flow hydrodynamics, geometric shape of the aeration tank, convective-diffusion transfer of the substrate and activated sludge, a 3D CFD model was built. The model is based on the three-dimensional equation of motion of an ideal liquid and the equation of mass conservation for the substrate, activated sludge. The field of sewage flow rate in the aeration tank is calculated based on the velocity potential equation. The process of biological transformation of the substrate is calculated on the basis of the Monod model. The splitting scheme was used for numerical integration of the equations of convective-diffusion transfer of activated sludge and substrate. The splitting is carried out in such a way to take into account the transfer of substrate (activated sludge) in only one direction at each step of splitting. The calculation of the unknown value of the substrate (activated sludge) concentration is carried out according to an explicit scheme. The Richardson method is used to numerically integrate the three-dimensional equation for the velocity potential, and the unknown value of the velocity potential is calculated by an explicit formula. Euler's method is used for numerical integration of equations describing the process of substrate transformation and change in activated sludge concentration (Monod model). Findings. The software implementation of the constructed 3D CFD model is carried out. A description of the structure of the developed software package is provided. The results of a computer experiment to study the process of wastewater treatment in an aeration tank with additional elements are presented. Originality. A new multifactor 3D CFD model has been developed, which allows quick assessing the efficiency of biological treatment in an aeration tank. Practical value. The constructed 3D CFD model can be used to analyze the efficiency of the aeration tank under different operating conditions at the stage of sketch design of wastewater treatment systems.

scholarly journals The capacity of wastewater treatment plants drives bacterial community structure and its assembly

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Young Kyung Kim ◽  
Keunje Yoo ◽  
Min Sung Kim ◽  
Il Han ◽  
Minjoo Lee ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Community Structure ◽  
Bacterial Community ◽  
Activated Sludge ◽  
Community Assembly ◽  
Bacterial Communities ◽  
Wastewater Treatment Plants ◽  
High Capacity ◽  
Operating Conditions ◽  
Rrna Gene

Abstract Bacterial communities in wastewater treatment plants (WWTPs) affect plant functionality through their role in the removal of pollutants from wastewater. Bacterial communities vary extensively based on plant operating conditions and influent characteristics. The capacity of WWTPs can also affect the bacterial community via variations in the organic or nutrient composition of the influent. Despite the importance considering capacity, the characteristics that control bacterial community assembly are largely unknown. In this study, we discovered that bacterial communities in WWTPs in Korea and Vietnam, which differ remarkably in capacity, exhibit unique structures and interactions that are governed mainly by the capacity of WWTPs. Bacterial communities were analysed using 16S rRNA gene sequencing and exhibited clear differences between the two regions, with these differences being most pronounced in activated sludge. We found that capacity contributed the most to bacterial interactions and community structure, whereas other factors had less impact. Co-occurrence network analysis showed that microorganisms from high-capacity WWTPs are more interrelated than those from low-capacity WWTPs, which corresponds to the tighter clustering of bacterial communities in Korea. These results will contribute to the understanding of bacterial community assembly in activated sludge processing.

An investigation into studying of the activated sludge foaming potential by using physicochemical parameters

2002 ◽  
Vol 46 (1-2) ◽  
pp. 525-528 ◽  
Author(s):  
K. Hladikova ◽  
I. Ruzickova ◽  
P. Klucova ◽  
J. Wanner
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Physicochemical Parameters ◽  
Wastewater Treatment Plants ◽  
Physicochemical Characteristics ◽  
Full Scale ◽  
Aeration Tank ◽  
Foam Formation ◽  
Individual Parameter

This paper examines how the physicochemical characteristics of the solids are related to foam formation and describes how the foaming potential of full-scale plants can be assessed. The relations among activated sludge and biological foam hydrophobicity, scum index, aeration tank cover and filamentous population are evaluated. Individual parameter comparison reveals the scumming intensity can be estimated only on the assumption that foams is already established. None of the above mentioned characteristics can be reliably used to predict the foaming episodes at wastewater treatment plants.

scholarly journals Unravelling diversity and metabolic potential of microbial consortia at each stage of leather sewage treatment

RSC Advances ◽  
2017 ◽  
Vol 7 (66) ◽  
pp. 41727-41737 ◽  
Author(s):  
Hebin Liang ◽  
Dongdong Ye ◽  
Lixin Luo
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Treatment Process ◽  
Sewage Treatment ◽  
Microbial Consortia ◽  
Biological Wastewater Treatment ◽  
Metabolic Potential ◽  
Ecological Functions ◽  
Wastewater Treatment Process ◽  
System P

Activated sludge is essential for the biological wastewater treatment process and the identification of active microbes enlarges awareness of their ecological functions in this system.

scholarly journals Time-series genome-centric analysis unveils bacterial response to operational disturbance in activated sludge

2019 ◽  
Author(s):  
María Victoria Pérez ◽  
Leandro D. Guerrero ◽  
Esteban Orellana ◽  
Eva L. Figuerola ◽  
Leonardo Erijman
Keyword(s):  
Growth Rate ◽  
Time Series ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Microbial Communities ◽  
Wastewater Treatment Plant ◽  
Treatment Plant ◽  
Operating Conditions ◽  
The Face

ABSTRACTUnderstanding ecosystem response to disturbances and identifying the most critical traits for the maintenance of ecosystem functioning are important goals for microbial community ecology. In this study, we used 16S rRNA amplicon sequencing and metagenomics to investigate the assembly of bacterial populations in a full-scale municipal activated sludge wastewater treatment plant over a period of three years, including a period of nine month of disturbance, characterized by short-term plant shutdowns. Following the reconstruction of 173 metagenome-assembled genomes, we assessed the functional potential, the number of rRNA gene operons and thein situgrowth rate of microorganisms present throughout the time series. Operational disturbances caused a significant decrease in bacteria with a single copy of the ribosomal RNA (rrn) operon. Despite only moderate differences in resource availability, replication rates were distributed uniformly throughout time, with no differences between disturbed and stable periods. We suggest that the length of the growth lag phase, rather than the growth rate, as the primary driver of selection under disturbed conditions. Thus, the system could maintain its function in the face of disturbance by recruiting bacteria with the capacity to rapidly resume growth under unsteady operating conditions.IMPORTANCEIn this work we investigated the response of microbial communities to disturbances in a full-scale activated sludge wastewater treatment plant over a time-scale that included periods of stability and disturbance. We performed a genome-wide analysis, which allowed us the direct estimation of specific cellular traits, including the rRNA operon copy number and the in situ growth rate of bacteria. This work builds upon recent efforts to incorporate growth efficiency for the understanding of the physiological and ecological processes shaping microbial communities in nature. We found evidence that would suggest that activated sludge could maintain its function in the face of disturbance by recruiting bacteria with the capacity to rapidly resume growth under unsteady operating conditions. This paper provides relevant insights into wastewater treatment process, and may also reveal a key role for growth traits in the adaptive response of bacteria to unsteady environmental conditions.

scholarly journals Fractal analysis of biological wastewater treatment efficiency

2018 ◽  
Vol 251 ◽  
pp. 06005 ◽  
Author(s):  
Nazira Dzhumagulova ◽  
Ilya Svetkov ◽  
Vladimir Smetanin ◽  
Nguyen Dinh Dap
Keyword(s):  
Wastewater Treatment ◽  
Comparative Analysis ◽  
Activated Sludge ◽  
Biological Treatment ◽  
Sewage Treatment ◽  
Quantitative Composition ◽  
Biological Wastewater Treatment ◽  
Treatment Facility ◽  
Wastewater Purification ◽  
Biological Methods

The purpose of the present research was to enhance the efficiency of biological wastewater treatment through the direct impact on the metabolism of activated sludge. In the course of research, species and quantitative composition of biological community of activated sludge in aeration tanks during wastewater purification process was studied. Comparative analysis was carried out for linen production wastewater and household sewage. Possible application of biological treatment in linen production was evaluated. Proposals were developed on creation of controllable biological treatment facility. In this paper, biological methods are shown to be efficient for household sewage treatment. Comparative analysis was carried out for linen production wastewater and household sewage. Possible application of biological treatment in linen production was evaluated. Proposals were developed on creation of controllable biological treatment facility.

Evaluation of the Effectiveness of the Use of Enzyme Complexes in the Process of Biological Treatment of Wastewater from Pulp and Paper Enterprises

2018 ◽  
Vol 22 (6) ◽  
pp. 15-19
Author(s):  
E.H. Sakaeva ◽  
L.V. Rudakova
Keyword(s):  
Waste Water ◽  
Wastewater Treatment ◽  
Beneficial Effect ◽  
Activated Sludge ◽  
Biological Treatment ◽  
Experimental Studies ◽  
Pulp And Paper ◽  
Technological Scheme ◽  
Biological Wastewater Treatment ◽  
Enzyme Complexes

The results of experimental studies on the evaluation of the possibility of using enzyme complexes in the biological treatment of waste water from pulp and paper enterprises are presented. The use of enzyme complexes will increase the efficiency of wastewater treatment by COD and BOD, and will also have a beneficial effect on the hydrochemical and hydrobiological characteristics of activated sludge. Experimental studies have determined the points of introduction of enzyme complexes into the technological scheme of biological wastewater treatment.

Modelling and simulation of the steady-state of secondary settlers in wastewater treatment plants

2001 ◽  
Vol 43 (7) ◽  
pp. 39-46 ◽  
Author(s):  
I. Queinnec ◽  
D. Dochain
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Wastewater Treatment ◽  
Steady State ◽  
Activated Sludge ◽  
Parameter Identification ◽  
Wastewater Treatment Plants ◽  
Operating Conditions ◽  
Sensitivity Studies ◽  
Activated Sludge Processes

This paper discusses the steady-state modelling of thickening in circular secondary settlers of activated sludge processes. The limitations of the solid flux theory basic models to represent steady-state operating conditions serve as a basis to introduce more sophisticated models derived from computational fluid dynamics. Parameter identification and sensitivity studies have been performed from lab-scale continuous experiments.

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