This paper presents the results of a challenge study conducted on two immersed low-pressure
membrane pilot plants using Bacillus megaterium spores. The reliability of
available theoretical models for relating direct integrity monitoring results to microbial
LRV is also evaluated. The challenge study
was conducted in the light of the proposed Long Term 2 Enhanced Surface Water
Treatment Rules (LT2ESWTR). Two important requirements of the proposed rule,
namely resolution and sensitivity of the direct integrity tests, were evaluated. Spores of
Bacillus megaterium (0.7 µm x 1.4µm) were used as surrogates for Cryptosporidium spp.
Duplicate challenge studies were conducted for each pilot plant. One of the main
differences in the two pilot plants was the fiber inside diameter with ZW1000a having an
inside fiber diameter of 0.35 mm vs. 0.75 mm for the ZW500d©. Membranes were
compromised with one and two pinholes, followed by one, two, or three cut fibers.
Multiple pressure decay tests were conducted for each condition. Includes 9 references, table, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 600 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 18 |
| Published : | 06/17/2004 |
