The methods describes new and efficient water aeration technology as aeration is the most expensive part of water treatment. This technology can dissolve oxygen at a faster rate while using minimal energy compared to other methods. Efficient and rapid regulation of water flow and the back pressure is the crucial element of this technology, especially when conducting experiments with the different funnels of different sizes to achieve specific regimes.
To begin set up the experiment, turn on the flow meter and start the underground water pump. Open the control valve and adjust the water flow to be significantly higher than the maximum flow required to form a water vortex. If necessary, tighten the clamp near the funnel outlet and raise the water level in the funnel's top cylindrical portion.
Next sequentially modify the water flow and water level values in the upper cylindrical portion of the funnel to set twisted and straight regimes. For the restricted regime, squeeze the clamp near the funnel outlet to create back pressure and set the flow rate to 882 liters per hour and the water level to three centimeters. Then change the flow rate to 936 liters per hour and the water level to nine centimeters.
For the tracer experiment, calibrate the pH probes by preparing two standard higher and lower pH solutions than the operating range. Measure the pH value of one standard pH solution and set the value in the data logger during the calibration. Similarly, measure the pH of a higher pH solution and set it in the data logger.
Then allow the data logger to calibrate the pH probes. Install pH probes at the inlet and outlet of the funnel. Start the recording mode.
Next start the experiment, ensuring the water vortex is stable. Fill the syringe with the prepared tracer mixture of sodium hydroxide and connect it to the tracer injection line. Quickly unscrew the valve in the injection system.
Then inject the tracer liquid, and finally screw the valve quickly. Once the pH is stabilized, save the pH peaks recorded during the passage of the tracer liquid through a glass funnel. To analyze the entry and exit peaks for HRT calculation, convert pH to sodium hydroxide concentration peak and take the start point of the first peak for the countdown.
Then take the point on the second peak which divides it into two figures of equal area for the conclusion of the countdown. For the DO experiment, install the DO sensor at the inlet and outlet of the funnel. Then install the temperature sensors near the funnel inlet and outlet.
Connect each sensor to the fiber optic oxygen transmitter. Then start the setup, ensuring the water vortex is stable. Start recording mode, and once the DO concentration is stable, record the data.
The twisted regime had a double helix shape and the largest interface between water and air, whereas the straight regime had a smooth straight shape and a smaller interface between water and air. The restricted regime took the form of twisted or straight vortices, depending on the water level;however, its length changed depending on the application of back pressure. The water flow should be quickly controlled to avoid overflows, and calibrated sensors should be used to obtain reliable data.
Our ongoing project involves developing a new wastewater treatment technology that integrates plasma discharge to generate oxidants in the gas space and a water vortex to dissolve them in water.
