Simulation Of Ozone Transfer In Water. Comparison With A Pilot Unit

A computer simulation of a bubble column is established to determine the residual ozone concentration in the air and the dissolved ozone residual in the water. This study is aimed to improve the control of ozonation systems, both technically and economically.

The program is based on mass balances along the contact column, which take into account the ozone consumption due to both the self-decomposition and the reactions with organic compounds contained in the water. The experimental measurements allow quantification of the ozone concentration in the air at the inlet and outlet of the pilot unit, as well as the dissolved ozone concentration at different heights along the column. A relation between the transfer coefficient, k_La, and the superficial velocity of the ozonated air is established. It is specific to the diffusion characteristics of the pilot unit. The k_La then is reintroduced in the program.

The calculated and the measured values are shown to be similar regarding the transfer yields, the dissolved ozone concentrations at the pilot unit outlet and the profiles of dissolved ozone concentrations along the contact column. Using the program, the influence of the most important parameters of ozonation on the transfer (treatment rates, initial ozone concentration in the air, pH and organic content of the water, k_La values) have been simulated.