Selecting activated carbon for micropollutant removal in drinking water treatment: Trace capacity number test

This research explores new GAC testing protocols that can be used to assist in the selection of activated carbon for geosmin and MIB removal in drinking water treatment. The trace capacity number (TCN) in liquid- and gas-phase show promise of being fast and simple tests that yield information about the number of high-energy adsorption sites on carbon: a parameter that is theorized to be more closely indicative of the ability of a particular GAC to adsorb organic micropollutants such as goesmin and MIB. Six different common GACs from several manufacturers were characterized using traditional parameters, as well as the TCN tests. Actual carbon performance was then evaluated in the laboratory using water from Lake Ontario that was spiked with 100 ng/L geosmin and 100 ng/L MIB, and directed through bench-scale column tests. The results indicated that as hypothesized, the conventional GAC characterization parameters (e.g. iodine numbers, adsorption isotherms) did not correlate well to actual geosmin and MIB removal performance as given by the column tests, but that the TCN and column tests yielded a similar best-to-worst ranking of the six carbons.