Rapid removal of trace HCHO from indoor air by an air purifier consisting of a continuous concentrator and photocatalytic reactor and its computer simulation

A mathematical model has been constructed for the removal of gaseous HCHO at a very low concentration level in a closed room by use of an air purifier that consists of a photocatalytic reactor combined with a continuous adsorption and desorption concentrator and the performance of the air purifier has been evaluated by computer simulation. The calculated result for the time course of the HCHO concentration in a 10 m3 closed room shows that the mathematical model can satisfactorily describe the time-transient behavior of the experimental values. The computer simulation for the treatment of HCHO in an actual dwelling house with the continuous release of HCHO from the building materials indicates that the air purifier can steadily keep the HCHO concentration below the WHO guideline (<80 ppb).