The objective of this powerpoint presentation was to evaluate the dependence of Cryptosporidium
oocyst and Giardia cyst removal on the influent
concentration of oocysts and cysts. The sampling approach included:
Grab Sampling
(10 L samples,
concentrated to 200 mL
with CSCC);
continuous sampling
(CSCC hooked up directly
to filter effluent for 30 hour
run time); and,
CSCC concentrated 288 L
of filter effluent to 200 mL. The analytical approach at Wisconsin State
Laboratory of Hygiene
(WSLH) included:
centrifugation;
fluorescent antibody
staining;
flow cytometry used to
separate microbes from
other particles in sample; and,
separated microbes placed
on slide and counted by
microscopy. The analytical approach at Marshfield Clinic
Research Foundation
(MCRF) included:
membrane filtration;
fluorescent antibody
staining; and,
counting under a microscope. Potential implications include:
water utilities using conventional surface water
treatment may not be achieving the level of oocyst
and cyst removal that they think they are
achieving;
when detected, typical counts in U.S. source waters are
on the order of 100 microbes/L or less; and,
extrapolation of Lake Mendota results to this level
suggests removal may only be 0.5 log to 1.0 log, rather
than 2.5 log to 3.0 log. Includes table.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 3.4 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 15 |
| Published : | 11/01/2007 |
