scholarly journals Computational Fluid Dynamics Modeling and Field Applications of Non-Powered Hydraulic Mixing in Water Treatment Plants

Water ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 939
Author(s):  
Tea In Ohm ◽  
Jong Seong Cae ◽  
Meng Yu Zhang ◽  
Jin Chul Joo
Keyword(s):  
Fluid Dynamics ◽  
Water Quality ◽  
Computational Fluid Dynamics ◽  
Energy Consumption ◽  
Water Treatment ◽  
Cfd Modeling ◽  
Vertical Shaft ◽  
Raw Water ◽  
Maintenance Costs ◽  
Water Treatment Plants

In this study, non-powered hydraulic mixing with three layers of baffles and holes was evaluated as an alternative to vertical shaft impellers in a rapid mixing process through both computational fluid dynamics (CFD) modeling and field applications. From the CFD modeling, the turbulence (i.e., vortex rings) caused by excess kinetic energy between the inlet and second-layer baffle ensures rapid mixing of the coagulants throughout the total water flow and overcomes the damping effect of the components in a mixing basin. Although optimal inlet velocity needs to be investigated for sufficient mixing between coagulants and pollutants in raw water with relatively low energy consumption and maintenance costs, non-powered hydraulic mixing developed in this study was proved to create strong turbulence and can be applied in any water treatment plants that involves coagulation-flocculation processes. Based on the comparison of the water quality between two water treatment plants using identical raw water and coagulant operated from 2014 to 2016, no difference in water quality of treated water indicated that non-powered hydraulic mixing can be replaced with vertical shaft impellers, hence, both energy consumption and maintenance costs can be reduced. Further study is warranted to optimize non-powered hydraulic mixing for the tradeoff between mixing efficiency and energy consumption in the water treatment plants.

scholarly journals Computational Fluid Dynamics Modeling of Rotating Annular VUV/UV Photoreactor for Water Treatment

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 79
Author(s):  
Minghan Luo ◽  
Wenjie Xu ◽  
Xiaorong Kang ◽  
Keqiang Ding ◽  
Taeseop Jeong
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Water Treatment ◽  
Cfd Modeling ◽  
Flow Mode ◽  
Oh Radicals ◽  
Dynamics Modeling ◽  
Rotational Movement ◽  
Contaminant Degradation ◽  
Wide Range

The ultraviolet photochemical degradation process is widely recognized as a low-cost, environmentally friendly, and sustainable technology for water treatment. This study integrated computational fluid dynamics (CFD) and a photoreactive kinetic model to investigate the effects of flow characteristics on the contaminant degradation performance of a rotating annular photoreactor with a vacuum-UV (VUV)/UV process performed in continuous flow mode. The results demonstrated that the introduced fluid remained in intensive rotational movement inside the reactor for a wide range of inflow rates, and the rotational movement was enhanced with increasing influent speed within the studied velocity range. The CFD modeling results were consistent with the experimental abatement of methylene blue (MB), although the model slightly overestimated MB degradation because it did not fully account for the consumption of OH radicals from byproducts generated in the MB decomposition processes. The OH radical generation and contaminant degradation efficiency of the VUV/UV process showed strong correlation with the mixing level in a photoreactor, which confirmed the promising potential of the developed rotating annular VUV reactor in water treatment.

scholarly journals Assessment of the Effluents of Basra City Main Water Treatment Plants for Drinking and Irrigation Purposes

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3334
Author(s):  
Suhad Almuktar ◽  
Ahmed Naseh Ahmed Hamdan ◽  
Miklas Scholz
Keyword(s):  
Water Quality ◽  
Water Treatment ◽  
Management Strategies ◽  
Arabian Gulf ◽  
Water Source ◽  
Raw Water ◽  
Water Contaminants ◽  
Water Treatment Plants ◽  
Quality Of Water ◽  
To Come

A severe water scarcity challenge is facing Iraq, which is predominantly due to the absence of water management policies, negatively impacting the water quantity and quality provision from the Tigris and Euphrates Rivers. Moreover, these practices have led to the intrusion of the Arabian Gulf salinity wedge into the Shatt Al-Arab River (SAR), which is the main water source for most water treatment plants (WTPs) in Basra city. In addition, the inadequate management and operation for most WTPs is another reason for the deterioration of water quality provided to Basra province. Accordingly, the aim of this study is to evaluate the performance of the main WTP within Basra province and to subsequently make recommendations for decision-makers to come up with new management strategies and policies. The effluents from eight WTPs were selected to study the quality of water supply for Basra city during the period between January 2018 and December 2018. The results showed that all WTPs were inadequate to treat raw water for drinking or irrigation purposes mainly due to the very bad raw water quality provided by the SAR as well as the lack of maintenance for such plants, resulting in very low removal efficiencies for various water contaminants.

Environmental analysis of chemicals and energy consumption in water treatment plants: case study of Oslo, Norway

2012 ◽  
Vol 12 (2) ◽  
pp. 200-211 ◽  
Author(s):  
G. Venkatesh ◽  
Helge Brattebø
Keyword(s):  
Water Quality ◽  
Global Warming ◽  
Energy Consumption ◽  
Water Treatment ◽  
Environmental Impacts ◽  
Quality Criteria ◽  
Water Treatment Plants ◽  
Environmental Life Cycle Assessment ◽  
Abiotic Depletion

This paper studies the trend in the consumption of energy and chemicals and the associated environmental impacts, for water treatment plants (WTPs) in Oslo, over the years between 2000 and 2009. The Norwegian Drinking Water Regulations stipulate that supplied water should comply with over 50 quality criteria. Abiding by the regulations and improving the water quality has its costs – economically and environmentally. Quality improvement entails, inter alia, the consumption of more chemicals, both in terms of quantity and variety, and a rise in energy consumption. In order to determine the environmental impacts of the consumption of chemicals and energy, an environmental life cycle assessment (LCA) was carried out. It was observed that the impacts of chemicals have increased dramatically after 2007, courtesy of a process upgrading at one of the WTPs. Except in the years 2004 and 2007, the impacts attributable to chemicals consumption have exceeded those due to energy consumption. Global warming is the key impact in both cases, though in the case of energy consumption, abiotic depletion and acidification are also significant.

scholarly journals A study on prediction method for ozone dosage and residual ozone concentration in advanced ozone water treatment

2017 ◽  
Vol 12 (1) ◽  
pp. 87-96 ◽  
Author(s):  
J. S. Hyung ◽  
K. B. Kim ◽  
M. C. Kim ◽  
I. S. Lee ◽  
J. Y. Koo
Keyword(s):  
Water Quality ◽  
Hydrogen Peroxide ◽  
Water Treatment ◽  
Environmental Factors ◽  
Real Time ◽  
Ozone Concentration ◽  
Prediction Method ◽  
Optimum Amount ◽  
Factors Affecting ◽  
Water Treatment Plants

Ozone dosage in most water treatment plants is operated by determining the ozone concentration with the experience of the operation. In this case, it is not economical. This study selected the factors affecting residual ozone concentration and attempted to estimate the optimum amount of hydrogen peroxide dosage for the control of the residual ozone concentration by developing a model for the prediction of the residual ozone concentration. The prediction formulas developed in this study can quickly respond to the environment of water quality and surrounding environmental factors, which change in real time, so it is judged that they could be used for the operation of the optimum ozone process, and the control of ozone dosage could be used as a new method in controlling the concentration of ozone dosage and the concentration of residual ozone.

Effect of Air Conditioning Position on Thermal Comfort in the Floor Air Conditioning System

2014 ◽  
Vol 493 ◽  
pp. 74-79
Author(s):  
Y.A. Sabtalistia ◽  
S.N.N. Ekasiwi ◽  
B. Iskandriawan
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Energy Consumption ◽  
Thermal Comfort ◽  
Energy Efficient ◽  
Air Conditioning ◽  
Air Conditioning System ◽  
Air Supply ◽  
Air Conditioning Systems ◽  
Air Diffusion

Energy consumption for air conditioning systems (air conditioning system) increased along with the increasing need for fresh air and comfortable in the room especially apartments. FAC system (Floor Air Conditioning) is growing because it is more energy efficient than CAC (Ceiling Air Conditioning) system. However, the position of the AC supply is on the lower level at the FAC system causes draft discomfort becomes greater as air supply closer to the occupants so that thermal comfort can be reduced. Heat mixture of windows, exterior walls, kitchen, and occupants in the studio apartment affect thermal comfort in the room too.This study aims to determine the position of the AC supply which has the best thermal comfort of FAC system in the studio apartment. It can be done by analyzing ADPI (Air Diffusion Performance Index), the distribution of air temperature, wind speed, RH (Relative Humidity), and DR (Draft Risk) to change the position of the AC supply supported by CFD (Computational Fluid Dynamics) simulation.This result prove that AC position 2 (on wall near the kitchen) is more comfortable than AC position 1 (on the bathroom wall) because AC position 2 away from occupied areas, thereby reducing the occurrence of draught discomfort.

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