AWWA ACE60014

This paper presents the results of a challenge study conducted on two immersed low-pressuremembrane pilot plants using Bacillus megaterium spores. The reliability ofavailable theoretical models for relating direct integrity monitoring results to microbialLRV is also evaluated. The challenge studywas conducted in the light of the proposed Long Term 2 Enhanced Surface WaterTreatment Rules (LT2ESWTR). Two important requirements of the proposed rule,namely resolution and sensitivity of the direct integrity tests, were evaluated. Spores ofBacillus 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 maindifferences in the two pilot plants was the fiber inside diameter with ZW1000a having aninside fiber diameter of 0.35 mm vs. 0.75 mm for the ZW500d©. Membranes werecompromised 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.

Product Details

Edition:

Vol. - No.

Published:

06/17/2004

Number of Pages:

18

File Size:

1 file , 600 KB