The aim of this work was the study a trickling biofilter, where water was circulated throughout the bed. In the first
steady state experiment, the packing materials used were 25mm Pall rings. The airflow rate was increased
gradually and the concentration of styrene in the air stream was held constant. In the second experiment, 15mm Pall
rings were used. In this case, the feed contained both styrene and a small amount of acetone. The concentration of
acetone and the air flow rate were kept constant, but the styrene inlet concentration was increased. The
concentrations were measured at the input, and also at an intermediate and the outlet position in the biotrickling
filter to determine the concentration profile along the reactor. Using the values of coefficient of determination (R2)
and the coefficient of variation of the fitted constant as criteria, a zero order model with diffusional limitation was
chosen as the best representation of the data. Then a further, third, set of experiments were done at unsteady state,
using step changes of the inlet concentration levels of both styrene and acetone at a steady air flow-rate . Inlet and
outlet concentrations were measured as a function of time and the results were adequately described using a simple
first order model.
