AWWA ACE54308

Cryptosporidium oocyst removal was evaluated during the filter ripening periods of pilot scale conventional and biological filters. The main objective of this study was to determine whether or not a high concentration of oocysts pass through the filter during the ripening period. Although previous studies did not find that this occurred, none of those studies spiked the preceding filter run (allowing oocysts to be present in the backwash remnants which compose a significant portion of initial filter ripening turbidity spike). Typically, the concentrations of oocysts found in the backwash remnants were no higher than those in water passing through the filter after the ripening period. Conventional and biological filters showed almost identicalremovals (roughly 2 Log) during this study, with the exception that biological filters had marginally lower concentrations of oocysts present in the backwash remnant samples. Overall, the ripening period did not appear to be a compromised portion of the filter run for Cryptosporidium passage as it is for particle counts and turbidity. A promising fluorescent polystyrene microsphere surrogate was also evaluated in this study and performed admirably. Includes 12 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

06/01/2001

Number of Pages:

11

File Size:

1 file , 340 KB