asparagus densiflorus, sulfur dioxide, phytoremediation, biofiltration


Sulfur dioxide is an inorganic compound (IC) and air pollutant that causes health risks in humans. The buildup of sulfur dioxide (SO2) in enclosed indoor spaces is, therefore, a concern to human health, especially since the average person spends 90% of his/her time indoors. This study focused on decreasing SO2 concentration in a cost-effective and simple way—by using botanical biofiltration, or the uptake of pollutants by plants. Research in biofiltration has focused mostly on the remediation of volatile organic compounds (VOC). However, research has also shown that plant species that remediate VOC efficiently also have the potential for efficient IC remediation. Asparagus densiflorus, which has a superior capacity for VOC uptake, has not yet been tested for the uptake of SO2. In order to fill that research gap, this study measured the difference in the amount of SO2 after 3 hours in an airtight container in the presence of an Asparagus densiflorus plant divided by the amount of SO2 present in the absence of the plant. This result was considered the fraction of SO2 remediated by the plant. The results in this experiment, although showing significant fractions of SO2 removal, were too variable to be conclusive about the amount of SO2 removed from an enclosed atmosphere and, therefore, of the biofiltration ability of A. densiflorus. Nonetheless, further research using a different research design is recommended to investigate whether A. densiflorus is more efficient than other plants at removing SO2 from the atmosphere and, therefore, could be used in biofilters.