0 MGD, a CBOD into aeration of 200 ppm, and aeration volume of 0. The Aeromax system is designed to provide years of trouble-free service using a water treatment method known as aeration. Buy Faucet Extender Aerator,1080° Rotating Universal Splash Filter Faucet,1080 Big Angle Swivel Faucet Aerator Sink Face Wash Attachment With 2 Water Outlet Modes - B + Faucet Ext. The flexibility of a blower system is crucial for the performance of the aeration system since plants need to handle a large variation in load. Additional References A-4. Observations on air distribution in each aeration tank. Each bed. Storm water retention tanks, and balancing tanks. 0mg/L is enough. 512. Types: With agitator, without agitator, Insulated. #5. After the full mixing of the air and water, aerated water from the device was injected into the fish tank. To calculate the aeration tank volume for wastewater treatment, you’ll need to determine the influent flow rate (e. Sep 25, 2017. The most widely-used and practical. Our containerized and skid-mounted units are modular and can be combined for systems that address larger flows and multi-stage treatment. Adding a pneumatic backflush system can virtually eliminate all. Find. Under this expansion project, Samsung C&T will be the exclusive partner in charge of engineering, procurement, and construction (EPC) as well as building three 187,000m³ LNG storage tanks, three loading facilities, and transport pipes. Aeration Tanks are an. Diagram of the aeration system used in the experiments. Several simulations are done for two different cases, dry weather and rain episode. Water testing of the new aeration tank (tank no. Center Enamel designs, manufactures and installs aeration tanks of 20 cubic meters to 25,000 cubic meters. Aerator w/Blow Molded Tank. based in Rancho Cucamonga, CALIFORNIA (USA) Superior Tank Co. Duke Indoor Aerator 500 Gal. Aerator Issue Hello, I have a float sitting in the aerator tank. Memasuki aerator, lumpur aktif dengan cepat memanfaatkan zat organik. SBR reactors treat waste water such as sewage or output from anaerobic digesters or mechanical biological treatment facilities in batches. The the day, week and year as well as along the aeration tank. To model theThis would either imply a surplus or deficiency in the existing works. Re: Aeration pumps for holding tanks. From a modest beginning in 1988, the Company has grown to become one of the leading manufacturers of electric water heaters in the Arabian Gulf. Includes. All wastewater from your bathrooms, kitchen and laundry is collected in the Septic Tank (or Primary Chamber). The weight of microorganisms under aeration, again fromAerators spray water into the aerator tank and let the sulfur dissipate through the air. 10 × 0. Introduction Aeration tank is an important part of activated sludge treatment system, and its cost accounts for a large proportion of the total cost of sewage treatment system. 3. The problem with conventional aeration tank control systems is that most plants neglect influent loading and set air-blowers at fixed dissolved oxygen (DO) concentrations of 2. aerobic oxidation of wastewater in waste treatment plants, fish water tanks, oxygenation of small ponds or water pools, etc. 3. biological processes require aeration and have a larger land footprint for the various. Rumaillah Group WLL. M. Choosing the Right Air Supplier. Modeling of aeration tanks based on a neutral density approach with steady Reynolds-averaged Navier-Stokes (RANS) simulations and the s k − ε turbulence model enables a relatively fast and straightforward prediction of the liquid-gas velocity fields and gas holdup; i. Activated sludge isn’t a thing, it’s a process. square foot of aeration surface: 0. Pawfly Aquarium 40 GPH Compact Air Pump Quiet Oxygen Aerator Pump with Air Stone Airline Tubing and Check Valve Accessories for 5-20 Gallon Buckets and Fish Tanks. . Using the. Pure Water Products Single Tank Aeration Systems are based on our years of experience with closed tank aeration (see our AerMax units ). 5 feet. The key parameter in this methodology is the air temperature variation that represents an. The model developed takes into account the main fluid dynamics parameters in the aeration tank. Bacteria that forms the activated sludge, after settling in a. know the nutritional requirements of your fish. Close valves 4 and 6 and open valves 1, 2 and 3, refill unit through valve 5 taking care not to over pressurise the tank. Aeration is an important step in wastewater treatment in every. Over-aeration wastes energy and can negatively affect process performance. study of agitation and material transfer phenomena in a biological reactor activated sludge type mechanically stirred tank. This can be used on any 750GPD to 1000GPD device that is more commonly seen. 25 million gallons, and an MLTSS of 2500 ppm. Yellowpages. Buy yourself a 12V bait tank aerator and run the aerator hose to a hose barb you fabricate in the top of your holding tank. Grand 16000 venturi jet aerator pump with 3 jet nozzle 1 fou. Our Price: $ 699. Use the Allied Molded Products LLC AERATOR 160 Gal. Messages 6 Reaction score 0 Points 1. 6 FILTER BACKWASH BLOWERS, SAS TANK BLOWERS,. Indoor cover with exhaust blower. 2. 2 to 0. The transformation of a traditional aeration tank to MPSR was mainly divided into three steps. Doha. Emission characteristics. <br><br>Railway experience in MRT Sg Buloh ~ Kajang, Penang. Municipal and industrial wastewater applications. An aeration tank of the wastewater treatment plant Werdhölzli, Zurich serves as an example for the complex flow features that evolve in such tanks. Included in this video is an awesome time-lapse of the process. Foaming in activated sludge process is a common operational problem in many wastewater treatment plants. This filter should be cleaned approximately every 6 months. The system includes a spray bar and mist nozzles for convenience. 32, and 0. Turn on the electric power supply after all the water drains from the aerator tank. Primary treated effluent is mixed with the returned activated sludge from the secondary settlement tank and uniformly distributed in channels for aeration with the help of mechanically driven aerators. Oxygen is needed by the bacteria to allow biodegradation to occur. The YardBreather measures 40 inches high, with plugging spikes spaced 8 inches apart, and it weighs a little more than 3. For a conventional aeration tank, the DO level most frequently selected (and usually required by regulatory agencies) is 2 mg/l. These are vented out by the automatic Air Vent on top of the De-aerator Head. INVEST’s mixing, aeration systems treat Qatar’s wastewater | Wastewater Digest. The biodegradation of organic matter under anaerobic conditions is a very slow biological process. 61-66, 2022. 06 MGD. ¾” pipe connectors with bypass valve. Using the pressure provided by a well pump. The total cost depends on how long you plan to keep the tool in your possession, and which model you select. Aerators are a non-chemical alternative for reduction or removal of unwanted gasses or odors. Published: 01 Mar 2021 - 12:06 pm | Last Updated: 01 Nov 2021 - 04:07 pm Abdullah Ibrahim Jaidah & Sons (100% Qatari Company) was established in 1973 in the State of Qatar as a manufacturer of Tents & their Accessories and later on expending the expertise and business to Car Parking Shades, Tents, Tensile Shade Structure solutions across the GCC region; we have more than Fifty years of experience in designing specialize structures. 147 4. Sizing for the aeration tank capacity is usually determined by the amount of wastewater the system is designed to take in per day. Theoretical background and calculation of mixing aeration tank. Constructed of all FDA approved materials. HELP LINE 1-800-722-3212. Four of the company’s first-generation HST 2500 machines have been doing that job for almost two decades at the Deventer wastewater treatment plant in the Netherlands. Aerators work on two principles and those are Hendry’s Law and Gas solubility. The following point shuld be taken. 7. The size and type of air stripper . 1 Conventional aeration. It is the most energy-consuming part of the wastewater treatment process, accounting for 50% to 60% of the energy consumption of the entire wastewater treatment plant. Rob Decker, senior project coordinator at Roquette, was searching for new technology to reduce maintenance time and costs associated with his aeration tanks. Weam Saad. Constructed of all FDA approved materials. This aerobic atmosphere activates bacteria that help break down solids and waste. The pond has no flow to mix layers and the warm water can’t hold enough oxygen so fish start swimming near the surface. As you now see, aeration is not mandatory if your fish tank already has. Henry’s law is a gas law that states that the amount of dissolved gas in a liquid is proportional to its partial pressure above the liquid. $3999. In addition, the top of all components of the aerobic treatment system, excluding the trash tank and the dispersal field should be covered with no more than 24 inches of soil. Doha, Qatar. 6 % respectively. the reactor, the aeration phenomenon with the performance of agitators and developSulzer’s HST™ turbocompressors were specifically designed for the water industry’s need for high volume, low pressure air to feed aeration tanks. Best Push Spike: Agri-Fab 16-Inch Push Spike Aerator. Landia supplied the first mixers for aeration tanks in the 1980s. evaporate VOCs. Aerators mix the water column enough that dissolved gas concentrations are equalized. Put on latex gloves. They can be supplied in a submersible version where the entire aerator is lowered into the tank or for mounting through the side of the tank - dry-installed. The Hiblow HP 120LL (Long Life) Air Pump has an extremely high-quality air pressure system which results in a 5. Aeration systems are designed to increase the air-water interface within a process liquid, allowing for sufficient oxygen transfer required to support the biological processes. 8) Sludge Drying Beds- This unit is meant for dewatering and drying the excess biological sludge. Note that this pipe length must not exceed 4 feet in length. This lets the aquarium water that is on the water surface to absorb more oxygen from the air. 2020 ). These are access ports for inspection and maintenance for the aeration tank. 05 %, 93. The size of your tank will determine the minimum flow rate that your air pump should be able to handle. These aerators are ideal for large circular or rectangular tanks and usually have a single header down the middle of the tank. let us discuss the working principle of deaerators in detail and how there are applied the deaeration process. 99 $ 29. Hussein, “Factors Affecting Coverage Ratio of Fine Disc Air Diffusers in Aeration Tanks,” International Research Journal of Advanced Engineering and Science, Volume 7, Issue 4, pp. The effluent of the aeration tank was received by two circular secondary settlers (diameter: 23. Hendry law. Aeration in food. Bubble Diameter: 1 mm. 5–6. Each jet aerator can be fitted with the most efficient pump and number of ejector pipes (1-4) to suit a specific tank. The Best Explanation. 2 m. 49 MG. 09) started at Doha West WWTW Old Plant. minimum required oxygen should be 2mg/L to4. The plant comprised storm tanks, detritus channels, primary sedimentation, mechanical aeration, final sedimentation and sludge digestion. Reply. With Landia’s aerators, you can keep the wastewater fresh in your wastewater tanks. Mixed liquor out of the aeration tank is made to settle in the secondary settlement tanks. aeration tank should be worked out considering the return sludge volume. It is clear to see that aerators are the key. Continued testing, research and development has meant that we have kept up with the times and today can offer energy-efficient mixing combined with the longest equipment life in the industry – something we are of course willing to guarantee! The most simple aeration tank is the complete mix tank provided with one surface aerator or with bubble aeration on the bottom. Browse 120 wastewater aeration photos and images available, or start a new search to explore more photos and images. When the aeration compartment is empty, close valve number 2. Average aerosolization rate was 7. 5 Cubic foot of Centaur carbon filter media. 15. Based on this centrifugal removal method, aerated grit tanks were designed to generate a mixing loop with enough momentum to maintain suspension of the organic particles and to extend the. Each aeration tank had a volume of 2469 m 3 (area: 588 m 2). Three Volunteers Three members of the staff volun teered to test the. August 2009; Journal of Environmental Engineering 135(8):684-691;the De-aerator Head before it enters the feed tank and the boiler . The power usage in mass transfer operations is very important in judging the aera-tion performance of the aerator. Jetting volume: 2. The cost of the works was £9 million at 1963 prices. The mixed liquid then enters the settling or. of aeration tanks to produce a huge number of very fine air bubbles. Aeration is the process of reducing the concentration of volatile organic compounds at the inlet. Page 1 of 224 DOHA SOUTH SEWAGE TREATMENT WORKS Phase II Expansion Civil Project 361/1 Public Works Authority. 022MPa Adjustable High Output Air Stone Bubbler. 115V. 4 litres of air is required for 1 litre of water. This process can take up to 24 hours. If the system was properly tuned, the. Optimizing your aeration processes Although we offer the best aeration equipment, equipment isn’t everything. Experimental studies were performed in a laboratory scale, two-phase, liquid-gas reactor, 0. We are based in the UK and our team has more than 30 years’ experience designing, constructing and deploying algal photobioreactors,. If you have a large pond, you may want. Aeration Treatment Unit (Consists of Aeration Tank and Aerator) - Traps scum and solids, provides treatment through retention time and aerobic bacteria digestion, settles solids before effluent enters the dosing chamber. The water supply pressure to the deaerator should be at least 2 bar to ensure good distribution at the nozzle. 2. View Product . 106 – 0. any shaped surface aeration tanks [5,6]. 58" E, that shown inEditor’s Rating: Why we like it: The MarineLand Penguin Power Filter gives the beneficial bacteria in your tank a much-needed boost with its Bio-Wheel technology, on top of its 3-stage filtration, reliable design, and adjustable flow rate features. 2CFM max airflow resulting in 120LPM of air. Power consumption is a basic integral quantity in an aerator, which determines the other processes involved in aeration phenomena such as ‘mass transfer rates’, ‘gas hold up’ etc. Results showed that the bioaerosol concentration from microporous aeration tank (20-262 CFU m-3) was one order of magnitude lower than rotating disc aeration tank. Pump or drain the aeration compartment contents overboard. Doha, Qatar. Result of the study shows that within 12 hours, 8 hours, 6 hours and 4 hours of hydraulic retention time (HRT) in aeration tank and sludge circulation ratio 0f R = 1. the percentage by volume of the gas (air) in the multiphase mixture in the reactor. Additionally, because the use of pure oxygen avoids the compression and stripping of large amounts of nitrogen, the power requirements and emissions are lower than in regular aeration. The all in one AquaTek Pro aerator will remove up to 10 ppm hydrogen sulfide, 10 ppm of iron contaminants and turbidity! Don’t suffer from iron staining or rotten egg smells anymore!The advantages of diffused aerators include the following: More complete mixing from bottom to top: Unlike surface aerators for wastewater management, which provide strong mixing primarily at the surface, diffused aerators provide complete mixing throughout the wastewater. aeration tanks or reducing mixed liquor suspended solids [10-16]. Save 5% with coupon (some sizes/colors) FREE delivery Wed, Nov 1. Dimensioning is based on two parameters: contact time at peak output (approximately 10 to 30 minutes regarding the conception) and a rapidly assimilated COD loading applied to the zone. Measure the lengths of pipe necessary to join the pressure tank to the aerator just below the tank pressure gauge. of aeration tanks to produce a huge number of very fine air bubbles. Authors. #9. Aerators for wastewater. Measure the lengths of pipe necessary to join the pressure tank to the aerator just below the tank pressure gauge. AERATION . The. The weather forecast in Doha, shown in Table 2, shows humidity in the range of 26–55%. Air pressure at each aeration tank. 4 units 1 additional unit; Clarifiers (suction type) 8 units ; 2 additional units . Best Handheld Core: Yard. Once settled in a separate settling tank, bacteria forming the "activated sludge" flocks are continually recirculated back to the aeration basin, increasing decomposition rates. Aerators. 115V. Thus, an optimum aeration intensity needs to be found which strikes a balance between these. 0 m. This study developed a new type of micro-pressure swirl reactor (MPSR) for treating rural domestic sewage with variable water volume in northern China. 500. Indoor cover with exhaust blower. Aeration is an activated sludge process, promoting microbial growth in the wastewater. mathankumar says: 10/02/2017 at 11:48 AM. Quorum quenching also offers a strong potential for fouling control but pilot-scale testing is required to explore the feasibility of full. 9. 1" L x 2" W x 1. Fig. [7,8]. AQUA TB is a specialized company in outdoor and indoor containerized & non containerized RO plant that provides information, technical assistance and marker research over products and / or markets for business clients or special Projects. The solenoid valve is 110 vac and is on the outside of the aerator tank. 3 to 4. How the system works: The AIO air filter maintains. Distributor in Doha, QATAR Newterra is a recognized leader in modular, decentralized solutions for water, wastewater, groundwater, and stormwater treatment. 1 offer from. Open app. Table 3 displays the average concentrations of aerosolized S. Currently, two blowers are supplying air to diffusers submerged 20 feet in theThe SBR tank 10 L, operating in 8 h with filling continuously, 30 min of the aeration (repeating 6 times), 50 min of the non-aeration (repeating 6 times), settling 40 min, draw/idle 10 min. The Company manufactures a range of domestic and large capacity storage type electric water heaters under the brand names of ‘HOTEX’ & ‘SUNEX’. In theory, oxidized forms of P are not released into. . Often used before a catalytic carbon backwash filter as a second stage. Once settled in a separate settling tank, bacteria forming the "activated sludge" flocks are continually recirculated back to the aeration basin, increasing decomposition rates. Aeration tanks are typically sold as continuously operated skid-mounted units. Aerators will reduce/remove unwanted odors, gasses, and VOC's from your water supply, and also reduce water borne radon. Readily available treated wastewater is used to fill up the tank with… | 19 comments on LinkedIn The settled sludge from Clarifier tank is recirculated to the Aeration tank for maintaining the MLSS concentration. Mechanical aerators usually have an efficiency in clean water of less than half of this a typical figure being 3. Aeration is an activated sludge process, promoting microbial growth in the wastewater. Qatar Petroleum awards North Field expansion project contract for LNG storage and loading facilities. Readily available treated wastewater is used to fill up the tank with… | 19 comments on LinkedInThe effluent is then led to anaerobic digester. Well Pump. Typical coarse-bubble diffusers provide an oxygen transfer rate of about 2. Hence, the first step in designing is to choose a suitable value of q c (or F/M) which depends on the expected winter. 5 m) with a liquid depth of 4. First phase of the project, which is currently under implementation, will deliver storage capacity of about 2,300 million gallons of water in 24 huge concrete reservoirs and some 480km of buried ductile iron pipelines. 302 kg/m 3 . The aeration system distributes and provides air supply (oxygen) in aerotanks to create the necessary oxygen regime (Dyagelev et al. Thethe day, week and year as well as along the aeration tank. Historically, inlet vanes or outlet dampers have been used to meet a varying demand but not in an energy efficient manner (WPCF & ASCE ). Authors claim that the tube aeration device is energy-saving equipment and is economically viable. Aeration experiments were conducted in a brick masonry tank of dimension 5. Billy Goat leads the industry in advanced technology reciprocating aerators, including the game changing PLUGR® cam-driven core aerators and the 30" "One & Done" hydrostatic aerator--an industry first, which raises. Waste water flow rate, Qo in (m3/d) Primary Effluent BOD5, So in (g/m3) Aeration Tank MLSS, X in (g/m3) Percentage volatile MLSS, in % Vol. Wastewater Aeration stock photos are available in a variety of sizes and formats to fit your. Permeability and make of diffusers installed in each unit, including the range of permeability conAeration provides oxygen to bacteria for treating and stabilizing the wastewater. Express delivery to Qatar, Doha. Apr 17, 2022. 25m×2. 115V or 220V with Exhaust Fan. Additionally, the methodology by which aeration uses is organic, cost-effective, and environmentally friendly. The aeration. Wastewater samples have been collected from aeration tank of Kima Wastewater Treatment Plant, Aswan, Egypt, coordinates 24°04'55. Gordon McKay. In the aeration tank, biological reactions _____ considerably below 5 °C. The typical optimum MLVSS-to-MLSS ratio in activated sludge plants is between . 6 pounds of oxygen. 300+ bought in past month. The microbes then feed on organic material, forming flocks which easily settle out. Another example is a directional aerator, like the one shown below in the middle. The model takes into account the dissolved and not dis-solved oxygen transfer in aeration tank. Plus they are backed by precise monitoring and control systems. The septic aerator pump breathes air into a holding chamber in your septic tank. to the aeration process are key to reducing energy consumption. F/M = QS O / XV. During start-up, the air bearing turbo initially starts in full-load operation, and maintains this operation for 10 minutes. Aeration is used in liquids, soils and foods to improve quality and reduce contamination. A sub-surface aeration system provides oxygen to microorganisms by injecting air into the wastewater. Aeration is a very natural process and environmentally green technology. These traditional operating systems are insensitive to influent conditions because of following pre-determined treatment static setpoints that disregard. Download Table | | Design analysis assumptions for selected aeration tank layouts from publication: Temperature modelling and prediction for activated sludge systems | Temperature is an important. 4 day-1 and SVI of 100 ml/gram. Aeration systems are designed to increase the air-water interface within a process liquid, allowing for sufficient oxygen transfer required to support the biological processes. Aeration Tank Loading lb BOD/day/1 000 cu ft Percent BOD (g BOD/m3 d) Removal 40 (640) 90 80 (1 300) 80 120 (1 900) 70 160 (2 600) 60 200 (3 200) 50 240 (3 800) 40 As with aeration time, aeration tank loadings in g BOD/m3-d (lb BOD/day/1000 cu ft) Work began in the early 1960s to install a modern treatment plant capable of treating 450,000 cubic metres per day of sewage. ر. Voi. To facilitate assembly and possi-ble future disassembly for cleaning, use union fittings at each tank, rather than “ hard pipe” the connections. You could also pipe the vent hole in the well seal where it could dump the excess water from the well, and there would be no pressure left to overflow the aerator tank. Aerator Tank Systems: These tanks allow the water to spray into the tank through aeration nozzles. . Good day to all. 5 pounds. cyclestopvalves. The Agri-Fab plug aerator has 32 galvanized plugs that will penetrate to a depth of three inches. Operational Considerations 41 G. Application: Fruit pulps and Juices. tubular fine bubble for wastewater treatment. ق. 0 mg/L in the aeration tank are:Sulzer ABS offerings: Waste water pumps, mixers, aerators, turbo compressors, flow boosters, progressive cavity pumps and macerators. Superior Tank Co. نوفمبر ٢٠٠٨ - مارس ٢٠١١ 2 من الأعوام 5 شهور. Bacteria break down organic matter in the wastewater for hours and transform it into harmless by-products. com. Higher aeration rates also increase the energy consumption leading to an increase in operating costs [62,63]. 2002; Voronov 2009). As the water is spraying, it. I pipes including fittings of Ductile Iron pipe in nominal trenching, construction of 100 Valve Chamber), Two Ground Reservoir (GLR) one of them inside the Doha airport with all. Air supply rate is 10 m3/ m2 of sewage /day. , 25(6), 1338-1343 (2008) SHORT COMMUNICATION Design considerations and economics of different shaped surface aeration tanks Achanta Ramakrishna Rao and Bimlesh Kumar† Civil Engineering Department, Indian Institute of Science, Bangalore, 560012, India (Received 16 May 2007 • accepted 12 April 2008). Occasional disinfection of the well can reduce the. SPP Pumps. Deskripsi Aeration Tank Proses Lumpur Aktif Aliran umpan air limbah/ subtrat, bercampur dengan aliran lumpur aktif yang dikembalikan sebelum masuk rektor. Able to hold 140 pounds of weight (4 concrete blocks), the steel construction will withstand years of use. sequencing batch reactors), which impacts blower technology selection. And as aeration is central to the level of efficiency in processing wastewater for disposal it is essential that you have the technology and equipment to meet these demands. 1. An aeration tank is a biochemical reactor designed according to the characteristics of microorganisms and uses the activated sludge method for wastewater. 1 Required Volume The size of the aeration tank for any particular adaptation of the process shall be based on the food-to-microorganism (F/M) ratio, using the influent BOD (load per day) divided by the mixed-liquor volatile suspended solids. Size (s): 4” x 2”. The foam can occur in aeration tank, secondary clarifier, as well as in anaerobic digester. Water Heaters Buy Online with Best Price. Aeration provides dissolved oxygen as an electron acceptor in the biological nitrogen and phosphorus removal processes and also provides mixing in the tank. They can be used for retrofitting an existing. 3. aerator. The waste sludge suspended solids concentration is 4900 mg/L. com. Aeration provides dissolved oxygen as an electron acceptor in the biological nitrogen and phosphorus removal processes and also provides mixing in the tank. 25" N and 32°55'40. and density of ventilation holes in the aeration pipes of the aeration tank, and also obtained the relationship between the changes of AVF and ventilation velocity in the aeration tank so as to define a better range of ventilation velocity. Scrub the insides and all portions of the aerator and tank using a sponge while wearing the gloves. Most municipal and industrial water treatment plants use. arabian equipment trading, gate 37, street 3013 zone 91, manateq free zone, barkat al awamer, doha, qatar + 974 55140215; sales@aet. The microbes then feed on organic material, forming flocks which easily settle out. Find out more on how Howden lead the way in smart aeration. 7. Under this expansion project, Samsung C&T will be the exclusive partner in charge of engineering, procurement, and construction (EPC) as well as building three 187,000m³ LNG storage tanks, three loading facilities, and transport pipes. Adding air through aeration is crucial, as it promotes bacterial growth and activity. Show abstract. Aeration is an important step in wastewater treatment in every industry. Premium Efficiency IE3 motors from 1. 42 %, 89 %, and 79. The result indicated that the accumulation of the N 2 O gas was highest at the non-aeration period, with an accumulation rate of around 8. 2. Open valve number 1 and empty the settling tank. A. such as aeration tank water levels4. The water is moved around the tank at a predetermined velocity.