Experimental Research On VOCs Emission Of Indoor Building Materials And Control Technology

Volatile Organic Compounds （VOCs） are a series of important indoor contaminants,which exist in the indoor air, doing harm to the people inside. At present, the main indoorpollution resources of VOCs are building and finishing materials. The research on the VOCsemissions of indoor building and finishing materials can provide reliable theoretical basis forindoor environment control as well as improving original control techniques. As a type ofnew technology of indoor pollution control, activated carbon-photocatalytic purificationtechnique is supposed to be the most applicable control technology in the future.This research tested the VOCs emissions under the conditions of different temperature,relative humidity and air change rate of dry and wet building materials using PGM-7240handheld VOC detector and other devices in an experimental chamber which simulates theindoor environment. By analyzing the test results, the author figured out the characteristiccurves and equations of the concentrations and emission rates of the contaminants. Theresearch also tested the control results of activated carbon-TiO₂composite photocatalyticpurification device on VOCs pollution. By altering the experimental conditions of ultravioletintensity, initial contaminant concentration, air velocity and TiO₂loading, the author studiedthe influences of the conditions on the purification efficiency. Based on the researches above,the author designed an activated carbon-TiO₂composite photocatalytic purifier andconducted performance and economic evaluation.The test results of VOCs emissions show that the rise of ambient temperature as well asthe increase of relative humidity can accelerate the emission of VOCs; the thicker the coatingof the wet material is, the higher VOCs concentration becomes inside the chamber; increasingair change rate of the chamber can improve the decay rate of the VOCs.The test results of the activated carbon-TiO₂composite photocatalytic purificationpurifying VOCs show that the composite purification device can effectively purify highconcentration VOCs pollution and have a relative high purification efficiency on exceedingstandard concentration VOCs pollution; The increase of ultraviolet intensity can improve thepurification efficiency; The higher the initial contaminant concentration is, the more effectivethe photocatalysis becomes; The air velocity has inverse relation to the purification efficiency,so maintain the air velocity of the system under certain level will help increase the time thatphotocatalysis needs and improve the photocatalysis efficiency; Higher TiO₂loading providesmore photocatalyst to the device and accelerates the photocatalysis.This research designed an activated carbon-TiO₂composite photocatalytic purifierwhich can purify indoor gaseous contaminants effectively, improving indoor air quality. The initial cost and operating cost of this composite purifier is low, and it has a wide applicationon indoor environment control.