Optimizing Ozone Removal with PRMs for Taza Aya’s NTP Module under Freezing Temperatures and Elevated Humidity at Michigan Turkey Producers (Student Poster #24)

Abstract Description: Worker safety is crucial in meat and poultry processing, particularly during turkey production, where the risk of airborne pathogen exposure is high due to congregated working environments. Taza Aya Inc. commercializes a wearable invisible visor utilizing nonthermal plasma (NTP) to inactivate airborne pathogens. However, the NTP module generates trace amounts of ozone ( < 200 ppb), poses risks to workers respiratory health and other specific medical conditions with prolonged exposure. Therefore, efficient ozone filtration is essential to ensure worker safety. Our previous study identified activated carbon (AC) Foam as an effective passive removal material (PRM) for ozone removal, achieving ~99% efficiency with minimal pressure drop of 1 Pa at 3 cfm under room temperature. However, workers at Michigan Turkey Producers (MTPs) often operate in harsh environments, including freezing temperatures ( < 40 °F) and high humidity (60-80 %RH) in the evisceration area, requiring PRMs need to be evaluated under these conditions.

The present study focuses on testing two ozone PRMs—activated carbon (AC) and Manganese dioxide (MnO2), in the form of granular and porous foam. The Carulite 200 catalyzes ozone breakdown chemically, while Arq’s granular AC is known for strong adsorption. The experimental setup features a fixed-bed reactor with compressed air conditioned by a vortex tube and water bubbler to simulate freezing and moist conditions at MTPs. An ozone generator and dilutor provide low ozone concentrations (~200 ppb). Ozone analyzers measure concentrations upstream and downstream, while a differential pressure sensor records pressure drops across the bed, and a hygrometer monitors relative humidity and temperature. The performance of ozone removal materials is evaluated by space velocities (flow rate/bed volume) and breakthrough curves.

Preliminary findings show that at 200 ppb of ozone and 3.75 cfm, AC foam achieved the highest ozone removal efficiency (~88%) at 55°F with 50% RH, maintaining stable performance over extended periods. A slightly lower efficiency (~84%) was observed at 55°F with 20% RH. At room temperature with 50% RH, efficiency was reduced (~76%) and exhibited a consistent decline, emphasizing the negative impact of higher temperatures. These results indicate the critical influence of environmental conditions, particularly temperature and humidity, on the performance of PRMs. Further investigation is required to validate long-term performance, including testing at lower temperatures (around 40°F) and elevated humidity levels of up to 80% RH. These studies will help optimize ozone filtration, ensuring worker safety and improving the reliability of Taza Aya’s wearable technology in diverse environmental conditions.

Keywords: Adsorption, Activated Carbon, Ozone Filtration, Freezing Temperature, Humidity