Continuous removal of both mutagens and mutagen-forming potential by an experimental full-scale granular activated carbon treatment system

Full-scale studies were being carried out on the performance of an experimental granular activated carbon column. Results are presented from experiments to assess the trends in the removal of mutagenic compounds over a 32-week period, representing conditions up to and well beyond the point at which the carbon was considered to be exhausted as regards removal of total organic carbon (TOC). No mutagens were detected in the settled water, so it was assumed that most of the mutagens entering the carbon column were products of the chlorination procedure. These compounds were preferentially removed by the carbon, and the effluent from the carbon column showed greatly reduced potential for formation of mutagens when the effluent was rechlorinated, even when the carbon was used for several months beyond normal use for TOC removal.