Reactors Used for Ozonation

Each reactor type has its characteristic hydrodynamic behavior. Knowledge of the hydro-dynamic behavior as well as its mass transfer characteristics is important for evaluating experimental results. Table 2-4 summarizes characteristic features of five important reactor types. 

Bubble columns (BCs) and stirred tank reactors (STRs) are the most frequently used types of reactors in laboratory ozonation experiments. Bubble columns can be roughly assumed to behave like perfectly mixed reactors with respect to the liquid phase, provided the ratio of height (h) to diameter (d) is small hid 10). 

In small lab-scale STRs almost complete mixing of the gas-phase can also be assumed whereas plug-flow or mixed behavior can be generally assumed for the gas phase in bubble columns (Marinas et. al., 1993 Stockinger, 1995 Huang et al., 1998) and packed towers (Lin and Peng, 1997). 

If the liquid as well as the gas phases are ideally mixed (i. e. the reactor behaves like a completely mixed STR, often called CSTR) the degradation processes can easily be calculated from integral mass balances for ozone and the dissolved target substances, 

Type of Reactor or Mass T ransfer System Type of Hydrodynamic Behavior Specific Power Consumption (kW m 3) 

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