Hydraulic and disinfection efficiency of an ozonation contactor for a municipal water treatment plant using computational fluid dynamics

2017 ◽  
Vol 95 (11) ◽  
pp. 2063-2072 ◽  
Author(s):  
Shahram Niazi ◽  
Mansour Kalbasi ◽  
Alireza Bahramian
2006 ◽  
Vol 6 (4) ◽  
pp. 9-16 ◽  
Author(s):  
J. Li ◽  
J. Zhang ◽  
J. Miao ◽  
J. Ma ◽  
W. Dong

Many approaches have been used to model the performance and efficiency of ozone contactors based on some assumptions to characterize the backmixing in fluids. Recently, computational fluid dynamics (CFD) technique has been proposed to simulate and optimize ozone contactors by calculating residence time distribution of fluid. To improve the ozone contactor performance of Bijianshan Water Treatment Plant in Shenzhen in South China, CFD was used for simulation and development of new optimization measures. Results showed that the low depth/length ratio of the contactor chambers in the original design resulted in short circuiting and backmixing, with the T10/HRT being only 0.40. Installation of guide plates substantially reduced short circuiting and backmixing with a much higher T10/HRT (0.66), increased by 73% compared with the original design.


2015 ◽  
Vol 17 (5) ◽  
pp. 745-762 ◽  
Author(s):  
Anastasios Stamou ◽  
Anthoula Gkesouli

A computational fluid dynamics model is presented for the calculation of the flow, suspended solids, and tracer concentration fields in the settling tanks of the water treatment plant of Aharnes, an important component of the water supply system of the greater area of Athens, Greece. The model is applied to investigate the expected negative effect of the wind on the hydraulic and settling performance of the tanks and to evaluate the improvement resulting from the installation of one and two baffles; the wind is modeled using a simple and very conservative approach that involves the setting of a constant horizontal flow velocity on the free surface. The model is calibrated and verified with field turbidity measurements. Calculations show that the effect of wind on the flow field and the hydraulic efficiency is strong, with the creation of massive re-circulation areas with intense mixing and high short circuiting; however, the effect of wind on the settling performance of the tanks is not pronounced. The removal efficiency of the tanks, which is 72.48% in calm conditions, is reduced to 68.07% for windy conditions; moreover, it increases to 70.00 and 71.04%, when one or two baffles are installed, respectively.


1999 ◽  
Vol 40 (4-5) ◽  
pp. 81-89 ◽  
Author(s):  
C. J. Brouckaert ◽  
C. A. Buckley

Computational Fluid Dynamics (CFD) studies of a secondary clarifier at Durban's Northern Wastewater Treatment Works, and of a clarifier at the potable water treatment plant at Umzinto, a small town near Durban, have been undertaken with a view to improving their load capacities. In both cases the units are located in relatively old treatment plants, which face continually increasing loads due to population growth. Increasing the capacity of existing equipment, rather than installing new equipment, constitutes an efficient use of development capital. Although the two clarifiers have considerable design differences, the CFD studies indicated remarkably similar circulating flows, which concentrate up-flow near the outer wall of the clarifier in the region of the clarified water overflow weirs. Baffles were designed to disrupt the circulation so as to distribute up-flow over a wider area, thereby reducing the maximum vertical velocities. In the case of the wastewater secondary clarifier, the modification has been implemented, and evaluated in comparative tests involving an otherwise identical unmodified clarifier. In the case of the potable water clarifier, the modification has still to be implemented.


2018 ◽  
Vol 44 ◽  
pp. 00045
Author(s):  
Justyna Górka ◽  
MaŁgorzata Cimochowicz-Rybicka ◽  
Beata Fryźlewicz-Kozak

This research was conducted to evaluate the effects of thermal and ultrasound disintegration on the disintegration degree (DD) of water treatment sludge from a municipal water treatment plant. A disintegration process was used to (i) improve subsequent coagulation efficiencies and dewatering processes (ii) reduce sludge production, and (iii) obtain both economic and enviromental benefits. The results show that using the disintegration process has an influence on DD values. It is also worth emphasising that the main parameter determining the efficiency of ultrasonic and thermal disintegration was the time of the applied process. Other parameters such as ultrasound intensity and temperature had a reduced impact on DD values.


2001 ◽  
Vol 43 (8) ◽  
pp. 35-41 ◽  
Author(s):  
I. A. Crossley ◽  
M. T. Valade ◽  
J. Shawcross

The paper describes the method that led to the design of the 1,500 Ml/day dissolved air flotation (DAF) water treatment plant for Boston's water supply. In particular, the topics of flocculation techniques, floated solids removal and DAF recycle as they relate to very large capacity plant design are covered in detail. The use of mathematical models, including computational fluid dynamics (CFD) software, to refine the design is described.


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