Evaluation of a new thermo-regenerative air cleaning device for reducing indoor exposure of multiple gas-phase contaminants

摘要

Background: There are many types of gas-phase contaminants indoors. Exposure to these compounds can cause some serious adverse health effects like allergy, cancer and leukemia etc. Adsorption technology is widely used to remove these pollutants for healthy indoor environment. However, the life span for indoor air pollutants is short, especially when the indoor concentrations of sub-ppbv level. Aims: This work aims to develop a new air cleaning device with thermo-regeneration for long term application. Methods: A thermo-regenerative air cleaning device is developed. Its removal performance for 8 kinds of indoor contaminants (acetaldehyde, ethanol, toluene, ethyl acetate etc.) is continuously validated in 30-round close-loop test and 6-round single-pass test. Each round spends 24 hours. After every round test, the device will be thermo-regenerative. The concentrations of contaminants were analyzed by GC-FID with the two-layer sorbent tubes (Tenax TA and Carbosieve Ⅲ). The influence of moisture concentrations to the removal efficiency of pollutants is also detected. Results: Although the removal efficiency of pollutants is decreasing initially with the round times increasing, it keeps stable after 30-round test. The average removal efficiency of all pollutants is larger than 90% finally. Moisture is found to have great negative or passive impact to the adsorption effect, which seems linking to the hydrophilic or hydrophobic performance of pollutants. Conclusions: The results indicated that the developed air cleaning device can efficiently and continuously remove common indoor pollutants. It can be used to reduce the indoor exposure of multiple gas-phase contaminants simultaneously.