Phytoremediation of formaldehyde by the stems of Epipremnum aureum and Rohdea japonica.

Decorative plants can efficiently purify formaldehyde and improve the quality of indoor air. The existing studies primarily revealed that the aerial and underground parts of plants' capacity to purify formaldehyde, while the performance of stems is unclear. A formaldehyde fumigation experiment was conducted on Epipremnum aureum and Rohdea japonica in a sealed chamber. Results showed the stems could remove formaldehyde. The efficiency of removal by the stems of each plant was 0.089 and 0.137 mg∙m-3∙h-1, respectively, the rate of purification was 40.0 and 61.6%, respectively. Both were related to plant species and the latter was affected by other factors like exposed area. To further explore the mechanism of phytoremediation, the correlation between the concentration of formaldehyde and CO2 during the experiment was investigated. Results showed when leaves of plants were exposed to formaldehyde, the concentration of CO2 increased with the decrease in concentration of formaldehyde, and the change in concentration of CO2 could be used as an indicator of the degree of decontamination of formaldehyde by the plants.