AWWA WQTC65763

The purpose of this paper is to report on results of studies of alternate strategies for Mn control including intermittent and seasonal regeneration of media in particle removal filters as well as the use of post filter contactors. The work is part of a soon to be completed American Water Works Association Research Foundation (AwwaRF) research project with a final report entitled "Characterization and Performance of Filter Media for Manganese Control" (Tobiason et al. 2007). Experimental methods used in this work included monitoring of full-scale plants and experiments conducted at bench and pilot-scale; details are provided elsewhere (Tobiason et al. 2007). Full-scale monitoring occurred at several plants operated by the Aquarion Water Company of Connecticut during 2005 when pre-filter chlorination practices were altered. Bench-scale experiments were conducted at the University of Massachusetts to assess the effectiveness of intermittent regeneration of filter media during or just after standard filter backwashing practices in restoring Mn(II) uptake capability. Media were backwashed with varied levels of oxidant (chlorine, permanganate) at controlled pH (6.3 or 7.5), different hydraulic loading rates, and different time periods. Pilot-scale experiments were conducted at Virginia Tech and participating utilities (Blacksburg, VA; Newport News, VA) to evaluate the performance of high-rate post filter contactors for Mn removal (Zuravnsky 2006; Knocke et al. 2006; Tobiason et al. 2007). Includes 26 references, figures.