MODELING ADSORPTION OF TCE BY ACTIVATED CARBON PRELOADED BY BACKGROUND ORGANIC-MATTER

Experiments with a natural water and a synthetic water were conducted to investigate systematically the effects of preloading of activated carbon by background organic matter on the subsequent adsorption of trichloroethylene (TCE). Equilibrium capacities and rates of adsorption were both found to decrease with increased periods of continuous preloading by both background waters. The effect of preloading by the natural water was observed to level off after several weeks. A pore diffusion model calibrated with adsorption parameters measured under different controlled conditions was used to predict fixed-bed adsorber breakthrough behavior. The modeling results indicated that equilibrium and rate parameters may need to be varied with preloading time to accurately predict target compound breakthrough for systems which undergo extensive preloading. A constant parameter approach appears adequate if preloading effects are small, or if the operating time of an adsorber is very long.