The Study of an Ultraviolet Radiation Technique for Removal of the Indoor Air Volatile Organic Compounds and Bioaerosol

Abstract

This study examined the use of high dosages of ultraviolet germicidal irradiation (UVGI) (253.7 nm) to deal with various concentrations of air pollutants, such as formaldehyde (HCHO), total volatile organic compounds (TVOC), under various conditions of humidity. A number of irradiation methods were applied for various durations in field studies to examine the efficiency of removing HCHO, TVOC, bacteria, and fungi. The removal efficiency of air pollutants (HCHO and bacteria) through long-term exposure to UVGI appears to increase with time. The effects on TVOC and fungi concentration were insignificant in the first week; however, improvements were observed in the second week. No differences were observed regarding the removal of HCHO and TVOC among the various irradiation methods in this study; however significant differences were observed in the removal of bacteria and fungi.

Spatio-temporal photolysis rate profiles of UV254 irradiated toluene

“…Photo-degradation is based on the irradiation of the substance by the UV sources 1 , 14 – 19 . The efficiency of the removal rate of pollutants by the UV irradiation, sensitively, depends on the UV energy and dosage, method of irradiation, the ambient temperature, relative humidity, air flow, the mixing of air in the environment and, unquestionably, the VOC’s functional groups 20 – 27 .…”

“…For instance, the UV-C (i.e., 100–290 nm with equivalent energies 12.4–4.3 eV) are able to dissociate formaldehyde and toluene molecules as the required energy, to break down the C–C and C–H bonds, lies in this band 11 , 45 , 46 . Definitely, this causes an alteration in the physical and the chemical properties of these UV irradiated molecules 20 .…”

Photocatalytic Oxidation of PLA/TiO2-Composite Films for Indoor Air Purification

“…An air purifier is an affordable, user-friendly, and easily accessible way to control chemical hazards . Technologies for VOC reduction include adsorption, liquid absorption, photolysis, membrane separation, bio-filtration, ozonation, plasma catalysis, biological degradation, and advanced oxidation processes such as photocatalytic oxidation . Photocatalytic oxidation (PCO) has been widely used and is well known for the treatment of VOCs because it can transform not only VOCs but also a wide range of pollutants to end products obtained from processes involving H 2 O and CO 2 ; it exhibits various advantages, such as operation at low pressure and temperature .…”

Does Prolonged Exposure of Environmental Fungi to Ultraviolet Irradiation Change the Pattern of Drug Resistance?

“…Ultraviolet ray is divided into the three groups of UVA (320 -400 nm), UVB (280 -320 nm), and UVC (200 -280 nm) based on wavelength (10,12,13). Among these types, the UVC ray has the shortest wavelength and the highest energy; as a result, it can induce great effects on spores (14,15). UV germicidal irradiation is a well-known method for inactivating a significant number of microorganisms and has wide application for sterilization.…”