Examination of the Chitosan Filter to Remove Formaldehyde from Building Materials

摘要

Formaldehyde (HCOH) is carcinogenic to human body. Due to some volatile decorating materials and the weather condition, e.g., high temperature and humidity in Taiwan, high level of formaldehyde in indoor air environment occurs frequently. Studies confirmed that chitosan-coated building materials can decomposes formaldehyde. In this study, the HCOH removal efficiency by chitosan-coated filters was examined. With different doses of chitosan (1.56 mg/m2, 3.44 mg/m2, 5.60 mg/m2) sprayed on the filter, the 24-hour HCHO concentration was assessed and then the HCHO removal efficiency under high (2 ppm) and low (0.5 ppm) inlet concentration was evaluated. The HCHO removal efficiency by barely 1 ml water-sprayed filter was also assessed. The results show that under low HCOH concentration, the HCHO removal efficiency by 1.56 mg/m2 chitosan-coated filter was 48.1%, which is a little lower than that under high HCOH concentration. In addition, the HCHO removal efficiency by barely 1 ml water-sprayed filter was 19.1% and 27.9 % under low and high HCOH concentration.