Determination of gas hold-up of Pasig River using dynamic gassing out method in a bubble column reactor

Abstract

This study determines the gas hold-up of Pasig River in a bubble column reactor using dynamic gassing out method by sparging air at different initial liquid height (13 and 25 inches) and superficial gas velocity (0.15, 0.20 and 0.24 cm/s) under atmospheric condition. Discrete grab water sampling was used for water sample collection. Experimental findings showed that the gas hold-up profiles were linear with respect to superficial gas velocity with R2 of 0.997 and 0.999 for 13 inches and 25 inches of liquid height, respectively. The values of gas hold-up decreased with increased liquid height to compensate for the increased in liquid holdup in the column. Experimental results showed that the desired sparging conditions was at high superficial gas velocity and at low initial liquid height in the reactor. The highest dissolved oxygen concentration resulted to the highest gas hold-up in the bubble column reactor. With the results of the study, the data of gas hold-up can be used for future studies to better understand the mass transfer mechanism of the aerated water sample in Pasig River, which eventually leads to the design and scale up of bubble column reactors and aerators for future rehabilitation projects of Pasig River to increase dissolved oxygen content.