A study on the adsorption characteristics of various sorbents for gaseous phase aldehyde by air server/thermal desorption - gas chromatography/mass spectroscopy (AS/TD-GC/MS) & Sensor

Abstract

Airborne gaseous formaldehyde (FA) is a typical pollutant in atmosphere and indoor air. The permissible indoor air quality FA standard is less than 82 µg/m3. Formaldehyde is to harmful influence to the human respiratory organ, especially for infants with weak immunity. An efficient methodology for airborne formaldehyde removal is needed as FA is the main cause of ‘Sick house syndrome’ (SHS). For this purpose, we selected these sorbents for evaluation; CBAP-1 (EDA), CBAP-1 (DETA), MOF-5, UiO-66-NH2, and Activated carbon. The FA concentrations investigated were 0.1, 0.25, 0.5 ppm for the AS/TD-GC/MS and 5, 10, and 25 ppm if using for sensor. The 10 % breakthrough volume (BTV 10) (L g-1) decreased while the experimental concentration increased. For example, the UiO-66-NH2 BTV 10 were 1,014, 523, 502, 54.8, 66.0, and 36.8 L g-1, respectively. The UiO-66-NH2 maximum adsorption capacity is 69.7 mg g-1 in 2.5 Pa. For evaluating the experimental results, we used Langmuir and Freundlich model which are typical isotherm adsorption model. The Langmuir isotherm was a better fit to the experimental isotherms than the Freundlich isotherm. The linearized Langmuir plots showed two distinct sorption profiles.