Abstract
The Wheeler-Jonas model is well known for its good prediction of breakthrough times for organic vapors on activated carbon beds. However, in its original form it is only valid under dry conditions: no prewetting of the filter and no humidity in the ambient air during use. The main parameter in the Wheeler-Jonas equation is the adsorption capacity, We. By measuring over 200 breakthrough times, with 7 different vapors on 3 different types of activated carbon, a satisfactory model for the influence of moisture on We was established. The only supplementary information needed, compared with the application of the Wheeler-Jonas equation under dry circumstances, is the water isotherm of the activated carbon.