Performance evaluation of ultrasonic transducer in a mist bioreactor by different nutrient media
The mist bioreactor has been shown to have a higher performance relative to the liquid phase reactor. To evaluate the performance of the misting system, water and conventional media (MS, ½ MS, and B5) were tested in mist bioreactor. The physicochemical properties of liquids at fresh state (zero treated time) and when treated for 1, and 2 hours was measured. At a given airflow rate, the misting rate for different height of various media was determined. The results demonstrated that the electrical conductivity of all media increased with the duration of sonication. The ultrasonic effect caused an increase in surface tension of MS and ½ MS, while the pH of MS and ½ MS reduced with ultrasonic treatment. The inverse trends were observed for water and B5 for these properties. The misting rate increased by increasing liquid height to a maximum value, then decreased to a minimum value at the highest height. For all liquids studied in this experiment, this maximum value of misting performed at height ranged between 3 to 4 centimeters. The maximum and minimum values of the ultrasonic misting rate was belonged to MS (2.78×10^(-2) gr/s) at height 3 centimeters and B5 (0.52×10^(-2) gr/s) at height 1 centimeters, respectively.