Granular Activated Carbon Adsorption Treatment for Removal of Trichloroethylene from Groundwater

Batch adsorption equilibrium experiments and continuous flow breakthrough experiments were conducted to compare the effectiveness of 7 granular activated carbons (GACs) in removing trichloroethylene (TCE) from groundwater. The order of GACs' adsorptive capacities for TCE was in the same order of their phenol numbers (indicator for internal surface of < 1 nm micropores). A small amount of methanol (0.05% v/ v) did not affect the pure water TCE capacities, which were notably reduced by the small organic constituents of tap water. The breakthrough results showed that the GACs' capacities for TCE were lower when it was removed from tapwater than the wellwater due to the greater competitive effect of its smaller organic constituents, that the lack of larger micropores of the higher capacity coconut carbons resulted in the lower capacity utilizations, and that the serial bed mode of treatment was necessary to attain a high capacity utilization for meeting a stringent discharge limit. The low cost, environmental friendly bamboo GAC is attractive since its competitive TCE capacity was readily utilized in actual treatment due to its favorable pore structure.