VOC REMOVAL AT LOW CONTAMINANT CONCENTRATIONS USING GRANULAR ACTIVATED CARBON

Small-scale beds of granular activated carbon (GAG) have been tested i n this research using challenges of volatile organic compounds (VOCs) in air at concentrations ranging from approximately 0.5 to 100 ppm. Th e research linked the performance of GAC from high-concentration quick ly completed tests to performance at low concentrations near those enc ountered indoors. For all tests, the carbon bed was approximately 2.54 cm thick and operated with a residence time of 0.11 s. The tests were conducted at 25 degrees C and 50% relative humidity. The measured 10% breakthrough times ranged from about 0.5 hour to several hundred hour s. For the individual compounds, the relationship between the logarith ms of breakthrough time and concentration was approximately linear ove r the experimental range, with different compounds producing lines hav ing different slopes. The measured breakthrough times compared favorab ly to published data and models. The results suggest that higher-conce ntration single-component breakthrough tests, which are short and easi ly obtained, may be cautiously extrapolated to indoor concentrations f or these compounds.