Simultaneous removal of multiple indoor-air pollutants using a combined process of electrostatic precipitation and catalytic decomposition

A synergistically combined process was studied for the removal of multi-pollutants in indoor air. Technologies including electrostatic precipitation and catalytic decomposition were integrated and investigated in a 3 m3 environmental chamber. Various sources of pollutants including cigarette smoke and building material were used to generate contaminants with complex composition. Simultaneous and effective removal of particulate matter, VOCs and ozone were achieved. The effective combination of the technologies synergistically improved the decontamination performance. Electrostatic precipitation removed particulate matter (94%-100% removal), while UV-catalysts oxidized VOCs (100% removal) within 20 min. In addition, during this process, the precipitator and VUV lights produced ozone (up to 360 ppb), initiated ozone-catalytic oxidation of gaseous pollutants, consequently enhanced the removal of VOCs. Moreover, an ozone depleting module was installed downstream to decompose the residual ozone, ensuring no ozone was released into ambient air. Notably, comparing with other reported works, the gas hourly space velocity in this work was high as 594,000 h−1, while the contact time of pollutants on the catalyst was short as 0.02 s. However, simultaneous and effective removal of real and complex pollutants was achieved under such circumstance. The experimental results also suggest that the combined process can effectively improve the indoor air quality.