AWWA WQTC60632

Sensitivity and reliability are two important issues for membrane integrity testing.Sensitivity of a membrane direct integrity-testing method is likely to govern the removalcredit granted to a membrane system. The recent data from a microbial challenge test onproduction plant scale validated the sensitivity of integrity-testing method the first timeand demonstrated high sensitivity of the pressure-hold test for a membrane system.Reliability, defined as the ability of an integrity-testing method, has not been a regulatoryfocus. However, it is a crucial issue when establishing upper control limit (UCL) forindirect integrity monitoring. The reliability of a membrane integrity-testing method canbe evaluated via probabilities of false negative and false positive signals generated by amethod and monotonic response to increasing severity of membrane integrity-breach.Because of randomness of a measurement, an UCL has to be established based on somestatistical characteristics of a sample population. Recent data indicated that many of theindirect integrity-testing methods are not only low in sensitivity, but also unreliable,which makes indirect-integrity monitoring rather difficult to implement. Includes 9 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

11/15/2004

Number of Pages:

11

File Size:

1 file , 480 KB