Stabilizing Soil Moisture and Indoor Air Quality Purification in a Wall-typed Botanical Biofiltration System Controlled by Humidifying Cycle

Abstract: The ultimate goal of this research is to develop a botanical biofiltration system that combines a green interior, biofilterin g, and automatic irrigation to purify indoor air pollutants according to indoor space and the size of biofilter. This study was pe rformed to compare the stability of air flow chara cteristics and removal efficiency (RE) of fine dust within a wall-typed (vertical) bo tanical biofilter depending on humidifying cycle and to investigate RE of volatile organic compounds (VOCs) by the biofilter. The biofi lter used in this experiment was designed as an integral form of water metering pump, water tank, blower, humidifier, and multi-leve l planting space in order to be suitable for indoor space utilization. As a result, relative humidity, air temperature, and soil moisture content (SMC) within the biofilter showed stable values regardless of three different humidifying cycles operated by the meteri ng pump. In particular, SMCs were consistently maintained in the range of 27.1-29.7% during all humidifying cycles; moreover, a humidifying cycle of operating for 15 min and pausing for 45 min showed the best horizontal linear regression (y = 0.0008x + 29.09) on SMC (29.0 ± 0.2%) during 120 hour. REs for number of fine dust (PM10) and ultra-fine dust (PM2.5) particles passed through the biofilter were in the ra nge of 82.7-89.7% and 65.4-73.0%, respectively. RE for weight of PM10 passed throu gh the biofilter was in the range of 58.1-78.9%, depending on humidifying cycle. REs of xylene, ethyl benzene, total VOCs (TVOCs), and toluene passed through the biofilter were in the range of 71.3-75.5%, while REs of benzene and formaldehyde (HCHO) passed through the biofilter were 39.7% and 44.9%, respectively. Hence, it was confirmed that the wall-typed botanical biofilte r suitable for indoor plants was very effective for indoor air purification.Additional key words: