In this paper, indirect and direct integrity methods are compared in a challengeexperiment with Bacillus subtillis spores used as a surrogate to Cryptosporidium oocysts.The challenge study was conducted with a cassette of 3 ZeeWeed(R) 500 ultrafiltrationmodules. Results for the intact membrane demonstrated a log removal value (LRV) largerthan 7.0 based on feed concentration. The LRV was reduced to 5.2 with a pinhole andfurther to less than 4.0 with the two cut fibers. Turbidity did not allow the detection of thepinhole or cut fibers. The permeate particle counters did show significant departures frombaseline when the membranes were compromised. Results are compared to LRVsestimated from a draft ASTM method. Includes 3 references, tables, figures, appendix.
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Edition: Vol. - No. Published: 03/05/2003 Number of Pages: 12File Size: 1 file , 280 KB