AWWA ACE61824

Pilot-scale results from the City of Boulder's 63rd Street Water Treatment Plant showed that while onlyweeks were required to achieve steady-state concentrations of attached biomass for a low-ozone dosedinfluent, acclimation with respect to MIB and geosmin removal at a 20 ng/L influent concentration was onthe order of months. For the first month of the study, percent removals for these compounds were lessthan 12%. By the fourth month, results for a 13 min empty bed contact time (EBCT) yielded up to 65%removal even though biomass values had not significantly increased. Results also indicated that shorterEBCTs (less than 8 min) often found in higher rate filters, may not be long enough for T&O control.A major issue with controlling MIB and geosmin is the highly varying source water concentration. Thepilot results showed a lag in the performance when the influent concentration was increased from 20 ng/Lto 80 ng/L. The full-scale biofilter (pre-granular activated carbon) results at the Greater Cincinnati Water Works (GCWW)showed that MIB and geosmin could be removed (32% to 96%) under varying influent concentrations (2 to398 ng/L MIB), with the lower removals associated with low influent concentrations and lowtemperatures. Other acclimation and biofilter performance factors include the impact of media-type andimpact of acclimation source. In this study, biologically active carbon (BAC) filters outperformed sandmedia filters and media acclimated off-site (at the GCWW) showed similar percent removals of MIB andgeosmin after being relocated and exposed to changes in influent water quality. MIB and geosminremovals recorded during this study are compared to two other pilot studies and six other fullscalebiofilters. Includes 18 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

06/17/2005

Number of Pages:

20

File Size:

1 file , 1.3 MB