Efficiency evaluation of commonly used methods to accelerate formaldehyde release and removal in households: A field measurement in bedroom

Abstract

Modern home interiors are prone to toxic gas emissions, such as formaldehyde, which can lead to respiratory diseases and cancer. Therefore, removing formaldehyde from households is crucial. This study measured the effects of common household factors (air temperature and light intensity) on formaldehyde release, and evaluated the efficiency of various removal methods (pothos, activated carbon, TiO₂ suspension, and ventilation) in bedroom. The formaldehyde release rate (K) ratio at different air temperatures: K₁₆ °_C:K₂₁ °_C:K₂₆ °_C = 0.474:1:1.65. Under different light conditions: K_UV-125lx:K_UV-324lx:K_INB-117lx = 2.407:4.099:1. Regarding formaldehyde removal, Pothos initially contributed to a fluctuation in formaldehyde concentration (C) due to vapor release, but had minimal overall impact on removal. Activated carbon and TiO₂ suspensions can remove formaldehyde. Activated carbon initially caused C to decline, followed by a subsequent increase. The TiO₂ suspension increased humidity, leading to an initial rise in C, followed by a decrease to a stabilized level. Ventilation led to a rapid drop in C, followed by an increase, and finally a decline, due to the dynamic balance between ventilation and K. Comprehensive evaluation of the net formaldehyde removal rate per unit volume (or per unit leaf area for pothos) revealed: activated carbon >TiO₂ suspension >pothos. At different air change per hour (ACH), the ratio of time required for formaldehyde removal (t) was t_ACH-10.89:t_ACH-54.39:t_ACH-108.78 = 1.825:1:0.754. Effect size analysis showed that Cohen's d for primary data was >0.5, combined with the K, C, and t results, temperature and UV irradiation were positively correlated with formaldehyde release, while ACH and activated carbon amount were positively correlated with formaldehyde removal.