Power Generation and Oxygen Transfer Analyses for Micro Hydro-Turbine Installed in Wastewater Treatment Aeration Tank

2021 ◽  
pp. 1-16
Author(s):  
Abdel Rahman Salem ◽  
Alaa Hasan ◽  
Ahmad Abdelhadi ◽  
Saif Al Hamad ◽  
Mohammad Qandil ◽  
...  
Keyword(s):  
Wastewater Treatment ◽  
Oxygen Transfer ◽  
Power Loss ◽  
Wastewater Treatment Plants ◽  
Aeration Tank ◽  
Hydro Turbine ◽  
Oxygen Transfer Efficiency ◽  
Aeration Process ◽  
The U.S ◽  
Water Height

Abstract This study targets one of the major energy consumers in the U.S. It suggests a new mechanical system that can recover a portion of the energy in Wastewater Treatment Plants (WWTPs). The proposed system entails a hydro-turbine installed above the air diffuser in the aeration tank to extract the water-bubble current's kinetic energy and converts it to electricity. Observing the optimum location of the turbine required multiple experiments where turbine height varies between 35% and 95% (water height percentages above the diffuser), while varying the airflow between 1.42 L/s (3 CFM) and 2.12 L/s (4.5 CFM) with a 0.24 L/s (0.5 CFM) increment. Additionally, three water heights of 38.1 cm (15”), 53.4 cm (21”), and 68.6 cm (27”) were considered to study the influence of the water height. It was noticed that the presence of the system has an adverse effect on the Standard Oxygen Transfer Efficiency (SOTE). Therefore, a small dual-blade propeller was installed right above the diffuser to directly mix the water in the bottom of the tank with the incoming air to enhance the SOTE. The results showed that the maximum reclaimed power was obtained where the hydro-turbine is installed at 65% - 80% above the diffuser. A reduction of up to 7.32% in SOTE was observed when the setup was placed inside the tank compared to the tank alone. The addition of the dual-blade propeller showed an increase in SOTE of 7.27% with a power loss of 6.21%, ensuring the aeration process was at its standards.

scholarly journals THE INFLUENCE OF AERATOR MOUNTING AND WASTEWATER TREATMENT PLANT DESIGN ON THE PERFORMANCE OF AERATION SYSTEMS

2010 ◽  
Vol 2 (5) ◽  
pp. 97-102
Author(s):  
Ala Sokolova ◽  
Mindaugas Rimeika
Keyword(s):  
Wastewater Treatment ◽  
Oxygen Transfer ◽  
Wastewater Treatment Plants ◽  
Oxygen Transfer Rate ◽  
Treatment Plant ◽  
Aeration Tank ◽  
Plant Design ◽  
Operational Parameters ◽  
Aeration System ◽  
The Impact

The paper analyzes the impact of the way of mounting a tube diffuser, the design of an aeration tank and the presence of a fixed carrier on the operational parameters of aeration systems used in small wastewater treatment plants. It was found out that the vertically mounted tube diffuser decreased standard oxygen transfer rate (SOTR) of the aeration system by approximately 20% and standard oxygen transfer efficiency (SOTE) by 25% comparing to the horizontally mounted tube diffuser. It was also defined that the design of the aeration tank might have an impact on the operation parameters of the aeration system: when the centre shell used to protect a diffuser was dismantled from a test tank, SOTR and SOTE increased by approximately 20%. It was also established that the presence of the fixed carrier in the aeration tank did not have an impact on the performance of aeration systems. Finally, research was carried out to compare the operational parameters of two diffusers of different types offered on the market and used in small wastewater treatment plants. It was found out that the performance different type diffusers might vary considerably.

Oxygen Transfer Efficiency of the Aeration Process in Refinery Waste Water Treatment

2008 ◽  
Vol 59 (2) ◽  
pp. 220-225
Author(s):  
Miroslav Stanojevic ◽  
Aleksandar Jovovic1 ◽  
Dejan Radic ◽  
Milan Pavlovic
Keyword(s):  
Waste Water ◽  
Experimental Investigation ◽  
Water Column ◽  
Oxygen Transfer ◽  
Mass Concentration ◽  
Waste Water Treatment ◽  
Motor Oil ◽  
Refinery Waste Water ◽  
Oxygen Transfer Efficiency ◽  
Aeration Process

This paper presents the results of an experimental investigation of aeration of water with a corresponding mass concentration of waste motor oil depending on the height of the liquid column for varied flow of air introduced into the water. The aeration process for water column heights of 1 and 2 m were investigated. The purpose of investigations performed on an experimental installation was comparison of technical indicators of the aeration process depending on the height of the water column and air flow in order to achieve more efficient purification of waste water.

Micropollutants Produced by Disinfection of Wastewater Effluents*

1982 ◽  
Vol 14 (12) ◽  
pp. 45-59 ◽  
Author(s):  
R L Jolley ◽  
R B Cumming ◽  
N E Lee ◽  
J E Thompson ◽  
L R Lewis
Keyword(s):  
Wastewater Treatment ◽  
Uv Irradiation ◽  
Base Pair ◽  
Wastewater Treatment Plants ◽  
Department Of Energy ◽  
Union Carbide Corporation ◽  
Organic Constituents ◽  
Chemical Effects ◽  
Base Pair Substitution ◽  
The U.S

The principal objective of this research program was to examine the effects of disinfection by chlorine, ozone, and ultraviolet light (uv) irradiation on nonvolatile organic constituents relative to chemical effects and the formation of micropollutants. In a comparative study of highly concentrated samples of effluents from nine wastewater treatment plants, it was determined that disinfection with chlorine or ozone both destroys and produces nonvolatile organic constituents including mutagenic constituents. The chemical effects of disinfection by uv irradiation were relatively slight, although the mutagenic constituents in one effluent were eliminated by this treatment. The nine wastewater treatment plants were selected by using the following criteria: disinfection method, nature of wastewater source, type of wastewater treatment, standards for quality of treatment, and geographical location. The treatment plants varied from pilot plant and small plants [0.05 m3/s (1 Mgd)] treating principally domestic waste to large plants [4.4 m3/s (100 Mgd)] treating principally industrial waste. Four plants used only chlorine for disinfection, four used ozone for disinfection, and one used uv irradiation for disinfection. Eight treatment plants used conventional secondary or more advanced wastewater treatment, and one plant used primary treatment. The following methodology was used in this investigation: grab sample collection of 40-L samples of undisinfected and disinfected effluents; concentration of the effluents by lyophilization; high-pressure liquid chromatographic separation of nonvolatile organic constituents in effluent concentrates using uv absorbance, cerate oxidation, and fluorescence detectors; bacterial mutagenicity testing of concentrates and chromatographic fractions; and identification and characterization of nonvolatile organic constituents in mutagenic HPLC fractions. With these procedures, over 100 micropollutants were identified in the wastewater effluent concentrates. Interplant comparison revealed considerable variability in the presence of mutagenic nonvolatile organic constituents in the undisinfected effluent concentrates as well as much variability in the destruction of the mutagenic constituents and the formation of other mutagenic constituents as a result of disinfection. Moreover, the effects varied on samples collected at the same wastewater treatment plant at different periods. No micropollutants known to be mutagens were identified in the mutagenic HPLC fractions separated from the undisinfected, chlorinated, and ozonated effluent concentrates. The mutagenic activity of the nonvolatile organic constituents in one chlorinated effluent concentrate was not attributable to organic chloramines. Most of the mutagens detected in effluent concentrates are direct acting and do not require metabolic activation. Both base-pair substitution mutagens and frame-shift mutagens occurred in the wastewater concentrates, but the former type was more frequent. For many of the compounds in effluents, strain TA-1535 was more sensitive than strain TA-100 in detecting base-pair substitution mutagens. *Research sponsored by the U.S. Department of Energy and the U.S. Environmental Protection Agency. The work was carried out at the Oak Ridge National Laboratory, which is operated by the U.S. Department of Energy under contract W-7405-eng-26 with the Union Carbide Corporation.

Usacerl's Experiences with Small Wastewater Treatment Plants in the USA

1990 ◽  
Vol 22 (3-4) ◽  
pp. 49-56
Author(s):  
E. D. Smith ◽  
R. J. Scholze
Keyword(s):  
Wastewater Treatment ◽  
Waste Treatment ◽  
Wastewater Treatment Plants ◽  
Remote Site ◽  
Corps Of Engineers ◽  
Military Installations ◽  
Recreation Areas ◽  
The Usa ◽  
Rotating Biological Contactors ◽  
The U.S

This paper presents a review of collected experience of one of the U.S. Corps of Engineers research laboratories in the area of small systems for wastewater treatment. Findings and experiences are presented for the use of package plants such as rotating biological contactors (RBCs), and remote site waste treatment at military installations and recreation areas.

The Staging of Large Wastewater Treatment Plants - A “Modular” Approach

1992 ◽  
Vol 25 (4-5) ◽  
pp. 67-73
Author(s):  
H. Fleckseder ◽  
L. Prendl ◽  
H. Meulenbroek
Keyword(s):  
Wastewater Treatment ◽  
Driving Force ◽  
Wastewater Treatment Plants ◽  
Aeration Tank ◽  
Modular Approach ◽  
Central European ◽  
Plant Hydraulics ◽  
The World ◽  
Whole Life Cycle ◽  
Over Time

The primary driving force for re-investments in wastewater treatment plants in Austria - and also other countries in Central Europe - is at present not an increase in load to treatment but a marked increase in effluent requirements to be fulfilled. (The re-investments necessary for sludge handling and treatment remain outside this paper.) Within a period of 20 years, the load specific requirements on aeration tank volume rose five- to tenfold, when Lv = 2.0 kg BOD5/(m3d) was the starting value, and roughly doubled for final clarifiers. In addition, the importance of the application and expansion of primary sedimentation decreased as well. This development over time in Central European countries as well as the need to utilize previous investments as long as possible - 35 to 60 years for civil works are common as periods of depreciation - indicate that investments in new plant at any location in the world have to consider the possible whole life cycle of a plant and that plant hydraulics becomes the “key hook” for expandability.

Bulking and Foaming Organism Control at Phoenix, AZ WWTP

1992 ◽  
Vol 26 (3-4) ◽  
pp. 461-472 ◽  
Author(s):  
O. E. Albertson ◽  
P. Hendricks
Keyword(s):  
Wastewater Treatment ◽  
Nitrogen Removal ◽  
Retention Time ◽  
Oxygen Transfer ◽  
Average Rate ◽  
Oxygen Transfer Efficiency ◽  
Solids Retention ◽  
Total Nitrogen Removal ◽  
The Cost ◽  
The City

A 1630 L/s activated sludge plant at Phoenix was limited to an average rate of 1050 L/s and operated, at 400-600 mg/L MLSS and 0.8-1.3 day solids retention time (SRT) due to bulking sludge and limited clarification capacity. Higher SRTs also produced uncontrolled Nocardia foaming and low dissolved oxygen due to partial nitrification. The City retained the services of a team of consultants to resolve these problems as well as to upgrade the plant to provide nitrification and total nitrogen removal. An anoxic selector design was implemented within the existing basin and the clarifiers were modified to improve inlet design and sludge transport. The modified advanced wastewater treatment (AWT) plant operating at 1450 L/s has averaged an effluent of 7.6 mg/L BOD5, 8.2 mg/L TSS, 1.3 mg/L NH4N, 4.1 mg/L NO3N and 2.9 mg/L TP. Oxygen transfer efficiency has increased about 80% in the nitrification-denitrification (NdeN) mode. The cost of modification/upgrading to AWT was approximately $730,000 and a 400 L/s increase in hydraulic capacity was realized. Upgrading costs were $5.63/m3 ($0.02/gal.)

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.

Non-Conventional Technologies for the Manufacturing Systems Use in Biological Wastewater Treatment Process

2015 ◽  
Vol 809-810 ◽  
pp. 1573-1578
Author(s):  
Casen Panaitescu ◽  
Monica Emanuela Stoica ◽  
Ciner Fehiman
Keyword(s):  
Wastewater Treatment ◽  
Oxygen Transfer ◽  
Manufacturing Systems ◽  
Wastewater Treatment Plants ◽  
Design Parameters ◽  
Biological Wastewater Treatment ◽  
Wastewater Treatment Process ◽  
Aeration System ◽  
Treatment Technologies ◽  
And Performance

Manufacture of wastewater treatment technologies is an important issue due to the complexity of design parameters and performance. Biological wastewater treatment is a process in which the intensity of oxygen transfer into water is an issue that has been extensively studied but yet insufficiently resolved. The present paper aims to describe an aeration system developed by the author in the laboratory by means of non-conventional technologies, and subsequently implemented in refinery wastewater treatment plants. The aeration system takes the form of modules, which are equipped with a new type of membrane. The analysis of the system performance revealed that oxygen transfer was 62%, specific adsorption of oxygen was 37 % and the specific oxygen transfer was 7%/m. The advantages of this new system are as follows: compared to existing technologies there is a higher rate of oxygen transfer into water; longer life; there are no dead zones in the basin as a result of their location; possibility of operating on separate sections.

Study of Air Bubble Formation for Wastewater Treatment

2011 ◽  
Author(s):  
Bryan A. Miletta ◽  
R. S. Amano ◽  
Ammar A. T. Alkhalidi ◽  
Jin Li
Keyword(s):  
Wastewater Treatment ◽  
Oxygen Transfer ◽  
Surface Membrane ◽  
Bubble Formation ◽  
High Oxygen ◽  
Transfer Efficiency ◽  
Intimate Contact ◽  
Rubber Membrane ◽  
Unit Process ◽  
Oxygen Transfer Efficiency

Aeration, a unit process in which air and water are brought into intimate contact, is an extremely important step in the process of wastewater treatment. The two most common systems of aeration are subsurface and mechanical. A mechanical system agitates the wastewater by various means (e.g. paddles, blades, or propellers) to introduce air from the atmosphere. Subsurface aeration is the release of air, in the form of bubbles, within the tank of wastewater to supply the microorganisms with the required amount of oxygen they need to metabolize and break down the organic material suspended in the wastewater. The bubbles of Air are released from the bottom of the wastewater tank through diffusers. These diffusers have a surface membrane, usually made of punched rubber, to create the fine bubbles with high oxygen transfer efficiency from supplied air to the diffusers. Since the energy crisis in the early 1970’s, there has been increased interest in these systems due to its high oxygen transfer efficiency. This paper covers experimentation of different air diffuser membranes, varying in material, used in the aeration process of wastewater treatment. Rubber, EPDM rubber (ethylene-propylene-diene Monomer) and PTFE Polytetrafluoroethylene membranes coated membranes were tested. Experimental results showed that the rubber membrane produced the smallest bubble size against expectation. This could be a result of the coating being on the top surface only and the bubble starts from inside the punch.

scholarly journals Improvement of Final Settling Tanks Performance by Using Chemical Additions

2019 ◽  
pp. 1-7
Author(s):  
Mohamed A. E. Halawa ◽  
Hanan A. Fouad ◽  
Rehab M. Elhefny ◽  
A. F. Wail
Keyword(s):  
Wastewater Treatment Plants ◽  
Settling Tank ◽  
Aeration Tank ◽  
Mechanical Equipment ◽  
Plant Model ◽  
Effluent Quality ◽  
Sludge Properties ◽  
Do Concentration ◽  
Aeration Process ◽  
The Impact

Biological treatment in wastewater treatment plants WWTPs consists of two main tanks, aeration tank and final settling tank. Aeration process using in return activated sludge system is very costly and it is required to operate WWTPs with low dissolved oxygen (DO) concentration in aeration process without risking poor effluent quality. To apply this study, a plant model for the addition of chemicals must be made with the necessary calibration of this model. Laboratory experiments were started between November 2017 and June 2018. This paper will discuss the impact of DO concentration on sludge properties by using a pilot plant model WWTP and find the optimum doses of Hydrogen peroxide H2O2 concentration with using low DO concentration to achieve good sedimentation.  In this study the DO set-point was changed every 3 weeks between 0.5 mg/l and 4.5 mg/l for a few months.  Experiments were carried out to The optimal ratio and dosage of H2O2 /Fe+2 was 5 as 30/6 mg/l. BOD, COD, TSS and VSS removal efficiency by using H2O2 /Fe+2 were 91%, 89% 90% & 89%, respectively with DO = 1.5 mg/l at an increased rates were 21.3%, 25.4%, 20% & 12.7%, respectively. Results of paper proves that the addition of optimum H2O2 will save 2 mg/l of DO concentration and providing a high cost of using electricity and mechanical equipment compared to the non-use of H2O2.

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