AWWA ACE93108

The presence of the background matrix is known to affect the adsorption capacity of granular activated carbon (GAC) for specific target compounds. The impact of five different background matrices, both natural and synthetic in origin, on the GAC adsorption capacity for 1,2-dichloropropane (1,2-DCP) was investigated using the batch equilibrium adsorption test (isotherm test). Both organic and inorganic matrices were considered. Isotherms were conducted under different types of conditions to assess the impact of the background matrix: 1)single-solute isotherms in laboratory clean water; 2) fresh carbon isotherms in the presence of the background matrix; and 3) isotherms with carbons preexposed to the background matrix. 1,2-DCP was chosen for study because it represents a regulated compound that is sometimes present in industrially impacted source waters. The MCL for this compound is 5 ug/L and the MCL goal is zero. 1,2-DCP is a weakly adsorbing compound which can be removed by both GAC and packed tower aeration. Because it is weakly adsorbing, any significant decrease in its GAC capacity by the background matrix will likely make removal of GAC uneconomical. The above elements make 1,2-DCP an interesting compound for examination.