Development of the new desiccator system for measuring the removal effect of the formaldehyde as an indoor air pollutant by the adsorbent

Abstract

The new desiccator system with measures for the prevention of dew drops and the processing of the formaldehyde (FA) gas discharged from the final desiccator was produced, and the FA removal rate for various adsorbents was examined. For the prevention of dew drops in the desiccator, a hygroscopic bottle containing silica gel was used next to the FA gas generator, and humidity was adjusted by adjusting the interval between the FA gas outlet (a) and the desiccant (b). The removal of the harmful FA gas discharged from the final desiccator (n = 5) is an important in the environmental preservation. To solve this problem, the FA gas was passed through an oxidation bottle containing KMnO4-H2SO4 solution, and it was possible to confirm the complete decomposition of the FA by increase of the CO2 and elimination of the FA. For the determination of the FA concentration in the desiccator, 100 ml air was beforehand collected using a gas collector into a 100 ml vial bottle containing 2 ml distilled water, and 50 ml of air from each desiccator was injected using a glass syringe. This was left under a slightly reduced pressure for 20 min, and the FA concentration was determined by the AHMT method. The FA removal rate after 1 h for each adsorbent (0.5 g) was 50% or more for chitin, KIMCO and silica gel. The removal efficacy for activated carbon was higher for fine particles than for coarse particles, and a dose-response relationship was established. © 2005 The Pharmaceutical Society of Japan.