Adsorption of Formaldehyde on the Surface of Environmental Test Chamber

The tracking experiments in an environmental test chamber for 25 d were carried out, including the stages of intrinsic formaldehyde concentration test, formaldehyde release, formaldehyde concentration attenuation, ventilation and formaldehyde release after it was adsorbed on the chamber surface. So it is necessary to investigate its releasing rules in order to improve the subsequent testing and propose guidance on the control of indoor pollution. The research results show that the formaldehyde concentration (C) in the chamber changes consistent with a logarithmic function: C=Alnt+B [when formaldehyde in the chamber releases, A0, B0, when formaldehyde attenuates, A0, B0, t is time (h)], where A is closely related to the relative equilibrium concentration established again after the adsorbed formaldehyde releases. Using suction type ventilation system for the chamber is in favor of residual formaldehyde reduction. After closing the ventilation system, the initial concentration of formaldehyde in the chamber increases quickly, and then a relatively low concentration of formaldehyde (0.3203mg/m3) will be established again in balance. Adsorption degree of formaldehyde in the chamber is related to the substrate surface adsorption ratio θ and hitting quantity of the adsorbate on the substrate surface U.