Pollution Patterns And Characteristics Of TVOC And HCHO In Residencial Indoor Air

In recent years, indoor air pollution has arroused attentions from both researchers and residents, for it’s becoming increasingly serious. There are a wide variety kinds of indoor air pollutants from a wealth of sources. Total Volatile Organic Compounds (TVOC) and formaldehyde (HCHO) are typical key indicators of indoor air quality, and have multiple sources, various concentrations and long exposure time.In this thesis, the review of volatile organic compounds (VOCs) and typical indicators (TVOC and HCHO) pollution in residences was summarized, and TVOC and HCHO concentrations and characteristics in residencial indoor air were focused on. Concentrations of TVOC and HCHO in two kinds of residences (newly-decorated homes and conventional homes) in Hangzhou were analysed, and characteristcis were studied. The results show that concentrations of TVOC and HCHO in newly-decorated residences were much higher than that in conventional ones, and have rather high over-limit ratios. The residential indoor air pollution was classified into three types:decoration pollution, trasition pollution and domestic pollution, according to three stages of indoor air pollution (newly-decorated stage, trastition stage and domestic stage), based on a TVOC concentration model. The results show mat the indoor air pollution in residences that were newly-decorated within9months is decoration pollution, and the main sources are building and decorating materials. The concentrations of pollutants are rather high and decay rapidly over time. The indoor air pollution in residences that were decorated for over16months is domestic pollutionm, and the main sources are human activities and household products. The concentrations of pollutants fluctuates with or without these sources. The indoor air pollution in residences that were decorated within9to16months is trasition pollution and it’s caused by both building and decorating materials and human activities. The sink effect of indoor materials was also investigated, the result shows that the sink effect of wallpaper to p-xylene varies in different ingredients and is influenced by temperature, and in perspective of sink effect, wallpeper of PVC and non-woven fabrics are more applicable in indoor decoration.Results of this study are believed to enrich the databased of indoor air pollution monitoring, help understand TVOC and formaldehyde pollution characteristics in residences, and support controlling indoor air pollution and improving indoor air quality.