scholarly journals Comparison between the performance of activated sludge and sequence batch reactor systems for dairy wastewater treatment under different operating conditions

2021 ◽  
Vol 60 (1) ◽  
pp. 1433-1445
Author(s):  
Alaa.H. Khalaf ◽  
W.A. Ibrahim ◽  
Mai Fayed ◽  
M.G. Eloffy
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Batch Reactor ◽  
Operating Conditions ◽  
Dairy Wastewater ◽  
Sequence Batch Reactor

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.

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.

The impact of powdered keramsite on activated sludge and wastewater treatment in a sequencing batch reactor

2019 ◽  
Vol 237 ◽  
pp. 305-312 ◽  
Author(s):  
Adam Masłoń ◽  
Janusz A. Tomaszek ◽  
Justyna Zamorska ◽  
Monika Zdeb ◽  
Adam Piech ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Activated Sludge ◽  
Sequencing Batch Reactor ◽  
Batch Reactor ◽  
The Impact

scholarly journals DairyWater: striving for sustainability within the dairy processing industry in the Republic of Ireland

2018 ◽  
Vol 85 (3) ◽  
pp. 366-374 ◽  
Author(s):  
William Finnegan ◽  
Eoghan Clifford ◽  
Jamie Goggins ◽  
Niall O'Leary ◽  
Alan Dobson ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Large Scale ◽  
Energy Use ◽  
Rainwater Harvesting ◽  
Batch Reactor ◽  
Dairy Wastewater ◽  
Processing Industry ◽  
Republic Of Ireland ◽  
Dairy Processing ◽  
The Republic

This Review describes the objectives and methodology of the DairyWater project as it aims to aid the Irish dairy processing industry in achieving sustainability as it expands. With the abolition of European milk quotas in March 2015, the Republic of Ireland saw a surge in milk production. The DairyWater project was established in anticipation of this expansion of the Irish dairy sector in order to develop innovative solutions for the efficient management of water consumption, wastewater treatment and the resulting energy use within the country's dairy processing industry. Therefore, the project can be divided into three main thematic areas: dairy wastewater treatment technologies and microbial analysis, water re-use and rainwater harvesting and environmental assessment. In order to ensure the project remains as relevant as possible to the industry, a project advisory board containing key industry stakeholders has been established. To date, a number of large scale studies, using data obtained directly from the Irish dairy industry, have been performed. Additionally, pilot-scale wastewater treatment (intermittently aerated sequencing batch reactor) and tertiary treatment (flow-through pulsed ultraviolet system) technologies have been demonstrated within the project. Further details on selected aspects of the project are discussed in greater detail in the subsequent cluster of research communications.

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.

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 Simulation for the Performance and Economic Evaluation of Conventional Activated Sludge Process Replacing by Sequencing Batch Reactor Technology in a Petroleum Refinery Wastewater Treatment Plant

2019 ◽  
Vol 3 (2) ◽  
pp. 45 ◽  
Author(s):  
Shahryar Jafarinejad
Keyword(s):  
Computer Simulation ◽  
Wastewater Treatment ◽  
Activated Sludge ◽  
Sequencing Batch Reactor ◽  
Petroleum Refinery ◽  
Batch Reactor ◽  
Refinery Wastewater ◽  
Conventional Activated Sludge ◽  
Petroleum Refinery Wastewater ◽  
Project Construction

Treatment of the petroleum refinery wastewater containing complex chemicals using biological processes is usually challenging because of the inhibition and/or toxicity of these matters when they serve as microbial substrates. In addition, performance modeling and cost evaluation of processes are essential for designing, construction, and forecasting future economic requirements of the petroleum refinery wastewater treatment plants (PRWWTPs). In this study, the performance and economics of conventional activated sludge (CAS) process replacing by sequencing batch reactor (SBR) technology in a two train PRWWTP were evaluated using simulation. The final treated effluent characteristics for the PRWWTPs containing CAS + CAS and SBR + CAS processes under steady state conditions were studied and evolution of the main parameters of the final effluent during the 30 days of simulation for these plants were investigated. Finally, the total project construction, operation labor, maintenance, material, chemical, energy, and amortization costs of these plants were estimated and compared. Results demonstrated that the project construction cost of PRWWTP containing CAS + CAS processes was lower than that of PRWWTP containing SBR + CAS processes and the energy and amortization costs for both plants were higher in comparison with the operation, maintenance, material, and chemical costs. Note that this study is a computer simulation and drawing general conclusions only on the basis of computer simulation may be insufficient.

scholarly journals Methodology for Energy Optimization in Wastewater Treatment Plants. Phase I: Control of the Best Operating Conditions

2019 ◽  
Vol 11 (14) ◽  
pp. 3919 ◽  
Author(s):  
Ana Belén Lozano Avilés ◽  
Francisco del Cerro Velázquez ◽  
Mercedes Llorens Pascual del Riquelme
Keyword(s):  
Wastewater Treatment ◽  
Control System ◽  
Activated Sludge ◽  
Phase I ◽  
Wastewater Treatment Plants ◽  
Energy Optimization ◽  
Industrial Process ◽  
Operating Conditions ◽  
Process Conditions ◽  
Real Time Control

Most purification systems work correctly from the point of view of water quality; purification, like any industrial process, must also be carried out efficiently with a minimization of costs. The overall project examined the potential benefits of using a recommended methodology for process evaluation and energy optimization in the aeration stage of activated sludge in the biological reactor at wastewater treatment plants (WWTP), which accounts for more than 44% of total operating costs. This energy control methodology encompasses the process, the installation and the control system. These three phases are examined in separate articles to make it easier to guide the user in the arduous task of optimizing energy efficiency of the WWTP from start to finish. This article focuses on Phase I of the methodology, the stage in charge of selecting the correct variables to control the best process conditions in the activated sludge system of the WWTP. Operating conditions that are a function of the recommended sludge age are influenced by exogenous factors such as temperature. The implementation of a real-time control system of the selected process variables, adapted to the needs, achieves reductions in the overall energy consumption of the installation, in this phase alone, of more than 15%, by reducing the oxygen requirements of the system and the recirculation ratios.

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