A Comparative Assessment of the Some Commercially Available Portable Bipolar Air Ionizers Particulate Pollutants (PM2.5, PM10) Removal Efficacies and Potential Byproduct Ozone Emission

Abstract

Indoor air cleaning interventions such as bipolar air ionizers have increased lately due to rampant air pollution and the COVID-19 pandemic. Hitherto, the bipolar air ionizer efficacy against particulate pollutants and byproduct ozone emission has not been fully understood and remained a critical concern. Currently, available diverse and complex methods are insufficient to determine commercially available bipolar air ionizer reliability. The National and International market of bipolar air ionizers is proliferating, while safety standards and information are comparatively limited, in such cases, any misleading information by manufacturers could be detrimental to consumers. To focus on those gaps, the present study comprised five different types of commercially available bipolar air ionizers labeled as BAI 1, BAI2, BAI3, BAI4, and BAI5, which were examined against the most concerned indoor particulate pollutants and potential byproduct ozone. Seven days of consecutive experiments were performed in five acrylic boxes, each box assembled with a testing bipolar ionizer model, calibrated air quality monitor, and particulate pollutant source (incense sticks). Two runs/day for each individual bipolar ionizer were performed for up to seven consecutive days. Overall performance was procured from the daily cumulative arithmetic average. All tested bipolar air ionizers models showed notable, up to 80% particulate matter (PM 2.5 and PM 10 ) removal efficiencies. The highest particulate matter removal was associated with bipolar air ionizers model 4 (PM 10 79.7%, PM 2.5 80.4%) and the minimum with BAI model 5 (PM 10 72.2%, PM 2.5 72.3%). Abnormal ozone emission was not observed with any bipolar air ionizer conduction in this study. Almost negligible elevation in background temperature (0.4 °C) and relative humidity (0.6%) were also observed. In conclusion, bipolar air ionizers could be byproduct ozone-free, indoor particulate matter removal, and low maintenance indoor air cleaning option.

Removal of incense smoke and corollary particulate matter using a portable bipolar air ionizer in an unventilated setup

“…Albeit, there is no abnormal ozone emission observed in this study. Similarly, in our previous study, comparative results from several bipolar ionizers showed up to 80% particulate matter removal efficiency of tested bipolar air ionizers and negligible ozone (Gupta et al, 2023). Current and previous study data indicates ozone emission is not always linked with bipolar air ionizers air cleaning.…”

“…The air quality monitor is rechargeable and can transfer real-time data by Wireless Fidelity (WiFi) to the laboratory computer. The air quality monitor is customized with the required sensors (PM 2.5 , PM 10 , CO 2 , O 3 , Temp., RH) which have been employed in our previous study (Gupta et al, 2023) During experiments, ambient Particulate matter (PM) concentration in the study area was derived from the nearby regional air quality monitoring station (Knowledge Park-V, Greater Noida-UPPCB) operated by the central pollution control board of India (https://app.cpcbccr.com/AQI_India/).…”

“…Bipolar air ionizers are simple electrical devices that produce electrically charged positive (H + ) and negative (O 2 − ) ions into the air, water molecules present in air breakdown into positive and negative ions due to the exposure to high voltage discharge generated by bipolar air ionizers. Those highly reactive ions react with air pollutants and cause agglomeration which lead settlement of several air pollutants, in case of microbial airborne contaminates OH − ions attract H + from microbial cell to form a water molecule, which causes the inactivation of airborne pathogens (Gupta et al, 2023).…”