scholarly journals The Study of Operating Conditions by Establishing Density Currents Generator for Improving of Water Quality on Lake Water - With Focus on DO and Water Temperature -

2014 ◽  
Vol 36 (4) ◽  
pp. 286-294 ◽  
Author(s):  
Young-Shin Lee ◽  
Kyung-Hee Han ◽  
Young-Kyu Kim ◽  
Hyung-Chul An ◽  
Sung-Woo Shin
Keyword(s):  
Water Quality ◽  
Water Temperature ◽  
Lake Water ◽  
Operating Conditions ◽  
Density Currents

scholarly journals Effects of dimensionality on the performance of hydrodynamic models

2021 ◽  
Author(s):  
Mayra Ishikawa ◽  
Wendy Gonzalez ◽  
Orides Golyjeswski ◽  
Gabriela Sales ◽  
J. Andreza Rigotti ◽  
...  
Keyword(s):  
Water Quality ◽  
Water Temperature ◽  
Flow Velocity ◽  
Numerical Models ◽  
Mixed Layer Depth ◽  
Water Reservoir ◽  
Density Currents ◽  
Hydrodynamic Models ◽  
Subtropical Zone ◽  
Drinking Water Reservoir

Abstract. Numerical models are an important tool for simulating temperature, hydrodynamics and water quality in lakes and reservoirs. Existing models differ in dimensionality by considering spatial variations of simulated parameters (e.g., flow velocity and water temperature) in one (1D), two (2D) or three (3D) spatial dimensions. The different approaches are based on different levels of simplification in the description of hydrodynamic processes and result in different demands in computational power. The aim of this study is to compare three models with different dimensionality and to analyze differences between model results in relation to model simplifications. We analyze simulations of thermal stratification, flow velocity, and substance transport by density currents in a medium-sized drinking water reservoir in the subtropical zone, using three widely used open-source models: GLM (1D), CE-QUAL-W2 (2D) and Delft3D (3D). The models were operated with identical initial and boundary conditions over a one-year period. Their performance was assessed by comparing model results with measurements of temperature, flow velocity and turbulence. Results show that all models were capable of simulating the seasonal changes in water temperature and stratification. Flow velocities, only available for the 2D and 3D approaches, were more challenging to reproduce, but 3D simulations showed closer agreement with observations. With increasing dimensionality, the quality of the simulations also increased in terms of error, correlation and variance. None of the models provided good agreement with observations in terms of mixed layer depth, which also affects the spreading of inflowing water as density currents, and the results of water quality models that build on outputs of the hydrodynamic models.

scholarly journals Cooling Performance Assessment of a Slinky Closed Loop Lake Water Heat Pump System under the Climate Conditions of Pakistan

Processes ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 553 ◽  
Author(s):  
Muhammad Kashif Shahzad ◽  
Mirza Abdullah Rehan ◽  
Muzaffar Ali ◽  
Azeem Mustafa ◽  
Zafar Abbas ◽  
...  
Keyword(s):  
Water Temperature ◽  
Heat Pump ◽  
Lake Water ◽  
Closed Loop ◽  
Operating Conditions ◽  
Coefficient Of Performance ◽  
Experimental Setup ◽  
Pump System ◽  
Climate Conditions ◽  
Heat Pump System

This paper presents an experimental evaluation of a closed loop lake water heat pump (LWHPs) system based on the slinky coiled configuration. Initially, a mathematical model is developed in the Engineering Equation Solver (EES) for the heat pump system and the submerged coils in a lake. System performance is determined for the submerged slinky copper coils under the various operating conditions. Afterwards, parametric analysis is performed considering different influencing parameters, such as the lake water temperature, ambient temperature, and mass flow rate of the circulating fluid at constant lake depth of 4 ft. The experimental setup is developed for 3.51 kW cooling capacity after cooling load calculation for a small room. In the current study, slinky copper coils are used to exchange heat with lake water. The experimental setup is installed in Taxila, Pakistan, and the system’s performance is analyzed during selected days. After experimentation based on hourly and daily operation characteristics, it is observed that the lake water temperature has significant influence on the heat transfer rate between slinky coil and lake water. While the lake water temperature in summer decreases and increases in winter with the depth. The resulted daily average coefficient of performance (COP) of the system is within the range of 3.24–3.46 during the selected days of cooling season. Based on these results, it can be concluded that the LWHP systems can be considered a viable solution for Pakistan having a well-established canal system.

scholarly journals Monthly Variations of Physico-Chemical Factors of Keenjhar Lake, Sindh, Pakistan

2019 ◽  
Vol 10 (1) ◽  
pp. 29-35
Author(s):  
Shahina Rao ◽  
Muhammad Arshad Azmi ◽  
Solaha Rahman
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Air Temperature ◽  
Lake Water ◽  
Fish Culture ◽  
Physico Chemical ◽  
Permissible Range ◽  
Chemical Factors ◽  
Monthly Variations

The present study was carried out with the aim to assess water quality using physico-chemical factors ofKeenjhar lake. For this purpose, lake water was analyzed with regular intervals. The air temperature ranged between 21°C to 38 °C, water temperature between 19 °C to 36 °C , pH 5.5 to 8, dissolved oxygen 2.26 mg/L to 6.81 mg/L,salinity 0.16 mg/L to 1.13 mg/L, alkalinity from 30 mg/L to 165 mg/L, acidity 8 to 110 mg/L, sulphate 2.6 mg/L to 310mg/L, phosphate from 1 mg/L to 31 mg/L and nitrates 16 mg/L to 180 mg/L during 2006, 2007 and 2008. It wasconcluded that various parameters lie within the permissible range except in a few months and suitable for drinking,irrigation and fish culture purposes.

scholarly journals Monthly Variations of Physico-Chemical Factors of Keenjhar Lake, Sindh, Pakistan

2019 ◽  
Vol 10 (1) ◽  
pp. 29-35
Author(s):  
Shahina Rao ◽  
Muhammad Arshad Azmi ◽  
Solaha Rahman
Keyword(s):  
Water Quality ◽  
Dissolved Oxygen ◽  
Water Temperature ◽  
Air Temperature ◽  
Lake Water ◽  
Fish Culture ◽  
Physico Chemical ◽  
Permissible Range ◽  
Chemical Factors ◽  
Monthly Variations

The present study was carried out with the aim to assess water quality using physico-chemical factors ofKeenjhar lake. For this purpose, lake water was analyzed with regular intervals. The air temperature ranged between 21°C to 38 °C, water temperature between 19 °C to 36 °C , pH 5.5 to 8, dissolved oxygen 2.26 mg/L to 6.81 mg/L,salinity 0.16 mg/L to 1.13 mg/L, alkalinity from 30 mg/L to 165 mg/L, acidity 8 to 110 mg/L, sulphate 2.6 mg/L to 310mg/L, phosphate from 1 mg/L to 31 mg/L and nitrates 16 mg/L to 180 mg/L during 2006, 2007 and 2008. It wasconcluded that various parameters lie within the permissible range except in a few months and suitable for drinking,irrigation and fish culture purposes.

Application of a Pilot-Scale Pulsed Electrocoagulation system to OCC-Based Paper Mill Effluent

TAPPI Journal ◽  
2009 ◽  
Vol 8 (3) ◽  
pp. 14-20 ◽  
Author(s):  
YUAN-SHING PERNG ◽  
EUGENE I-CHEN WANG ◽  
SHIH-TSUNG YU ◽  
AN-YI CHANG
Keyword(s):  
Water Quality ◽  
Quality Indicators ◽  
Paper Mill ◽  
Pilot Scale ◽  
Operating Conditions ◽  
Optimal Dosage ◽  
Water Quality Indicators ◽  
Paper Mill Effluent ◽  
Treated Effluent ◽  
True Color

Trends toward closure of white water recirculation loops in papermaking often lead to a need for system modifications. We conducted a pilot-scale study using pulsed electrocoagulation technology to treat the effluent of an old corrugated containerboard (OCC)-based paper mill in order to evaluate its treatment performance. The operating variables were a current density of 0–240 A/m2, a hydraulic retention time (HRT) of 8–16 min, and a coagulant (anionic polyacrylamide) dosage of 0–22 mg/L. Water quality indicators investigated were electrical con-ductivity, suspended solids (SS), chemical oxygen demand (COD), and true color. The results were encouraging. Under the operating conditions without coagulant addition, the highest removals for conductivity, SS, COD, and true color were 39.8%, 85.7%, 70.5%, and 97.1%, respectively (with an HRT of 16 min). The use of a coagulant enhanced the removal of both conductivity and COD. With an optimal dosage of 20 mg/L and a shortened HRT of 10 min, the highest removal achieved for the four water quality indicators were 37.7%, 88.7%, 74.2%, and 91.7%, respectively. The water qualities thus attained should be adequate to allow reuse of a substantial portion of the treated effluent as process water makeup in papermaking.

Improvement of Lake Water Quality by using Moving Rapid Water Treatment System

2018 ◽  
Vol 18 (1) ◽  
pp. 107-115 ◽  
Author(s):  
Kwang-Hee Lee ◽  
◽  
Min-Ho Kim ◽  
Nam-Woo An ◽  
Chul-hwi Park
Keyword(s):  
Water Quality ◽  
Water Treatment ◽  
Lake Water ◽  
Treatment System ◽  
Lake Water Quality ◽  
Water Treatment System

Subfossil insect remains (Chironomidae) and lake-water temperature inference in the Sisimiut–Kangerlussuaq region, southern West Greenland

2000 ◽  
pp. 78-82 ◽  
Author(s):  
Klaus Peter Brodersen ◽  
N. John Anderson
Keyword(s):  
Climate Variability ◽  
Water Temperature ◽  
Lake Water ◽  
Anthropogenic Impact ◽  
Biological Diversity ◽  
Biological Indicators ◽  
Lake Ecosystems ◽  
West Greenland ◽  
Physical Chemical ◽  
Temperature Inference

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Brodersen, K. P., & Anderson, N. J. (2000). Subfossil insect remains (Chironomidae) and lake-water temperature inference in the Sisimiut–Kangerlussuaq region, southern West Greenland. Geology of Greenland Survey Bulletin, 186, 78-82. https://doi.org/10.34194/ggub.v186.5219 _______________ Climate and water temperature have an important influence on the functioning of lake ecosystems. From limnological and palaeolimnological studies of lakes, information on biological diversity and climate variability in time and space can be gleaned from physical, chemical and biological indicators preserved in the lake sediments. The lakes in southern West Greenland are particularly useful for this purpose – they are numerous, diverse and have minimal anthropogenic impact (Anderson & Bennike 1997). Palaeolimnological data are fundamental for understanding the functioning and development of modern lakes and for understanding the causes of climatic change as well as the effect on lake biota.

A modeling approach to simulate impact of climate change in lake water quality: phytoplankton growth rate assessment

1998 ◽  
Vol 37 (2) ◽  
pp. 177-185 ◽  
Author(s):  
Hany Hassan ◽  
Keisuke Hanaki ◽  
Tomonori Matsuo
Keyword(s):  
Climate Change ◽  
Water Quality ◽  
Growth Rate ◽  
Dissolved Oxygen ◽  
Lake Water ◽  
Phytoplankton Growth ◽  
Quality Data ◽  
Model Parameters ◽  
Lake Water Quality ◽  
Phytoplankton Growth Rate

Global climate change induced by increased concentrations of greenhouse gases (especially CO2) is expected to include changes in precipitation, wind speed, incoming solar radiation, and air temperature. These major climate variables directly influence water quality in lakes by altering changes in flow and water temperature balance. High concentration of nutrient enrichment and expected variability of climate can lead to periodic phytoplankton blooms and an alteration of the neutral trophic balance. As a result, dissolved oxygen levels, with low concentrations, can fluctuate widely and algal productivity may reach critical levels. In this work, we will present: 1) recent results of GCMs climate scenarios downscaling project that was held at the University of Derby, UK.; 2) current/future comparative results of a new mathematical lake eutrophication model (LEM) in which output of phytoplankton growth rate and dissolved oxygen will be presented for Suwa lake in Japan as a case study. The model parameters were calibrated for the period of 1973–1983 and validated for the period of 1983–1993. Meterologic, hydrologic, and lake water quality data of 1990 were selected for the assessment analysis. Statistical relationships between seven daily meteorological time series and three airflow indices were used as a means for downscaling daily outputs of Hadley Centre Climate Model (HadCM2SUL) to the station sub-grid scale.

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