Particulate Matter Phytoremediation by Sansevieria trifasciata under a Simulated Microgravity System in a Pilot Testing Experiment: Effect of Watering and Plant Stress

Particulate matter (PM) pollution poses a profound challenge to human health and environmental sustainability, especially in extraterrestrial environments. Phytoremediation, a sustainable biotechnology, has emerged as a promising approach for air purification. This study investigates the potential of Sansevieria trifasciata to remediate PM under simulated microgravity (μG) conditions. Plants were exposed to PM in a 24-m 3 closed chamber under μG, achieved using a random positional machine. The results demonstrated that S. trifasciata maintained its PM removal capacity under μG across multiple cycles. After 16 h of exposure, the plant effectively removed PM 1 , PM 2.5 , and PM 10 , with removal efficiencies of (303 ± 41) μg/m 3 , (309 ± 54) μg/m 3 , and (353 ± 66) μg/m 3 , respectively. Notably, plant distance from the PM source did not significantly impact removal efficiency. To optimize phytoremediation, the effects of watering and plant growth regulators (auxin/IAA and gibberellic acid/GA 3 ) were examined. Watering was found to be crucial for maintaining photosynthetic efficiency (photosystem II activity), antioxidant capacity (ascorbic acid), and reactive oxygen species (ROS) levels, thereby enhancing PM removal. In contrast, IAA and GA 3 did not exhibit significant effects on PM phytoremediation. This study provides a foundational understanding of plant-based air purification in space environments. By leveraging the inherent capabilities of S. trifasciata , this research contributes to the development of sustainable and effective strategies for ensuring air quality in future space missions.