An experimental work to investigate the capabilities of plants to remove particulate matters in an enclosed greenhouse

Many studies, especially those conducted in laboratory chambers, have shown that plants are effective in removing indoor air pollutants. However, some researchers claim that laboratory results are not adequate evidence of validating the effectiveness of plants. Thus, an experimental work was designed and conducted by this research to investigate the capabilities of plants to remove particulate matters (PMs), given PM_2.5 and PM₁₀ are the primary air pollutants in both indoor and outdoor environment in China. The experimental results have indicated that an enclosed space had a lower PM concentration than the outdoor environment. In addition, plants can further reduce the indoor PM concentrations because they increased the surface area of the space. Airflow speed has adverse effects on the efficiency of plants’ PM removal. A relative slow airflow speed is beneficial to creating a stable indoor environment and to increase plants’ efficiency in removing PMs. The experiment recorded removal efficiencies of plants were approximately 0.2–0.36 for PM_2.5 and 0.24–0.39 for PM₁₀, respectively. Moreover, measures, such as reducing infiltration rate, can further increase the removal efficiencies.