AWWA WQTC64116

Despite the improved Cryptosporidium recoveries (relative to previous methods) that have beenobtained using U.S. Environmental Protection Agency method 1622/23, processing large volumes of raw and treated water hasremained a laborious, unreliable and costly task. Emelko and Reilly (2002) demonstrated increasing thenumber of counts in a sample can be integral to reducing the uncertainty in concentration and logremoval estimates. One strategy substantially reducing uncertainty associated with the concentrationand enumeration of C. parvum is to increase processed volume (with increased replication or improvedanalytical methods) so that at least several oocysts (at least ten or more as opposed to one or none) areobserved. This paper demonstrates a modified form of previously reported membrane filtration methodsfor Cryptosporidium and oocyst-sized surrogate enumeration. A critical and unique feature of thismodified method is that large volumes of water can be processed, concentrated, and enumerated.Preliminary investigations utilizing deionized water, groundwater, and treated surface water samples ofup to 2000L (and all with turbidities <0.3 NTU) have demonstrated C. parvum recoveries ofapproximately 45-50% and oocyst-sized microsphere recoveries of 70-90%. This approach provides acost-effective alternative method for conducting performance demonstrations and seeding experiments. Includes 27 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/01/2006

Number of Pages:

10

File Size:

1 file , 420 KB