Full- and pilot-scale GAC adsorption of organic micropollutants

Granular activated carbon (GAC) adsorption of 30 environmentally relevant micropollutants (MP) from four surface waters was investigated at the pilot-scale with empty bed contact times (EBCTs) of 7 and 15 min. An increase in background dissolved organic matter resulted in more and earlier MP breakthrough. Compared to an EBCT of 7 min, MP breakthrough at an EBCT of 15 min demonstrated 52% later breakthrough on average for five MPs on a throughput basis. A regression model was developed with data from three waters to predict MP throughput in bed volumes to 10% breakthrough (BV10%) based on the influent dissolved organic carbon concentration and the MP pH-dependent octanol-water partition coefficient, polarizability, and molecular volume. The regression model over predicted full-scale BV10% values when applied to a wastewater-water impacted water source and to GAC with a larger particle diameter, for which a particle size adjustment was able to account for most of the difference.