Volume 8, No. 2, June 2008, Pages 178-187 PDF(208 KB)
Adsorption Characteristics of Granular Activated Carbon and SPME Indication of VOCs Breakthrough
Department of Occupational Safety and Hygiene, Fooyin University, Kaohsiung County, Taiwan, Republic of China
Internal circulation cabinets equipped with granular activated carbon (GAC) to adsorb volatile organic compounds (VOCs) are extensively utilized to store bottles containing organic solvents in Taiwanese university, college, and hospital laboratories. This work evaluates the VOC adsorption capacity of GAC with various adsorption periods for 102–2652 ppm average inlet toluene concentrations at 27°C and relative humidity (RH) 72 ± 3%. Additionally, solid-phase micro- extraction (SPME) technology was employed for indicating the renew moment of GAC, and avoiding a breakthrough of toluene from adsorbents. Experimental results demonstrate that toluene adsorption capacity is linearly expressed as the natural logarithm of adsorption time (ln(t)) at a constant temperature, and the equilibrium adsorption capacity (Qe, g toluene/g GAC) for average 102–2652 ppm gaseous toluene was accurately simulated using the proposed models. The SPME fiber installed in the outlet air stream for adsorbing toluene exhausted through GAC effectively indicated the breakthrough of VOCs. The GAC-SPME operational instructions to indicate the replace time of adsorbent in the internal circulation cabinets are concluded in this study.c
Volatile organic compounds (VOCs); Emission; Solid-phase microextraction (SPME); Granular activated carbon (GAC).