Phytoremediation for indoor air quality (IAQ) improvement: removal efficiency of formaldehyde by epiphytic Tillandsia
摘要
Formaldehyde (FA) is a high-priority indoor pollutant with proven adverse effects on human health. Recent preliminary evidence has demonstrated that epiphytic Tillandsia plants can uptake airborne pollutants directly from the gas-phase. This study aims to further investigate on the phytoremediation potential of two Tillandsia species, T. velutina and T. ionantha, specifically focusing on their efficiency in removing FA. To conduct a comparative evaluation, experiments were designed and performed inside a test chamber with and without plants, under controlled micro-environmental and lighting conditions using the same FA emission source. Additionally, investigations on Tillandsia leaves, before and after exposure to FA, were carried out to understand the effect of FA absorption on plant metabolism. The experimental results revealed that T. ionantha exhibited a higher FA removal efficiency per leaf area unit (0.36 μg m−3 cm−2) compared to T. velutina (0.26 μg m−3 cm−2) and showed relatively higher FA tolerance. The unchanged FA levels before and after exposure, along with the reduction in Glutathione (GSH) content and the increase in soluble protein content in the leaves of both species, suggest that after absorption FA is rapidly metabolized.