An efficient plant–microbe phytoremediation method to remove formaldehyde from air

Abstract

In 2012, 7 million premature deaths were attributed to air pollution, of which 4.3 million to indoor air pollution inducing the “sick building syndrome.” In particular, formaldehyde, a toxic and highly reactive chemical, has been linked to cancer. The use of soil microbial biomass and plants to remove formaldehyde from polluted air by plants has been proposed, but there are so far few quantitative reports. Here, we developed an efficient plant–microbe technology to remove formaldehyde by adding cultured microorganism into the rhizosphere of three plant species, Tradescantia zebrina Bosse (T. zebrina), Aloe vera (Haw.) Ber (A. vera) and Vigna radiata (Linn.) Wilczek (V. radiata). Shoots were exposed to 0.72 mg of formaldehyde per m3 of air for 24 h. Results show that formaldehyde removal rates were 23.1 ± 0.1 μg/h/g fresh weight with microbes versus 18.5 ± 0.21 μg/h/g without microbes for A. vera, 86.4 ± 0.7 versus 59.3 ± 0.2 μg/h/g for T. zebrine and 97.6 ± 0.9 versus 25.1 ± 4.2 μg/h/g for V. radiata. Overall, formaldehyde removal was increased by 6.7–90.5% using microbes. Formaldehyde removal was influenced by light intensity, with this effect more pronounced in plant–microbe systems.