Predictive Models for Gaseous-Phase Carbon Adsorption and Humidity Effects on Trichloroethylene Adsorption

摘要

Theoretical models were applied to the adsorption of trichloroethylene (TCE) at influent concentrations ranging from 300 to 1350 mg/cum in air on granular activated carbon at low relative humidity. The models are shown to predict both the adsorptive capacity of activated carbon (maximum error < 8 percent). These low humidity data were then compared to TCE absorption by the same carbon at 25, 50, 65, and 85 percent relative humidities. Increasing levels of humidity had increasingly deleterious effects on the absorptive capacity of activated carbon at all TCE concentrations tested. The adverse effect caused by the presence of water vapor was more significant at the lower TCE concentrations than at the higher concentrations. The presence of water vapor not only decreased the carbon's absorptive capacity but also reduced its efficiency by increasing the dispersion of the breakthrough curve. Data at all humidity levels fit the Dubinin-Polanyi Isotherm equation equally well, indicating that the impact of water vapor on the adsorptive capacity of carbon for TCE is predictable and could be accurately modeled. Originator supplied keywords include: Freundich Isotherm, Langmuir Isotherm, Dubinin-Polanvi Isotherm, Trichloroethylene, Carbon adsorption, Activated carbon, Air Pollution Control, and Air Stripping Emissions Control.