AWWA MTC50288

This paper discusses two promising integrated membrane systems (IMSs) for disinfection of surface water: advanced physical/chemical treatment including coagulation, sedimentation, filtration (CSF), biological activated carbon filtration and slow sand filtration followed by reverse osmosis; and, microfiltration and ultrafiltration followed by ultralow pressure reverse osmosis. Spiking with MS-2 phages in the slow sand filtrate in the first system showed a removal capacity of 3.4 log units for reverse osmosis. Removal of spores of Sulphite Reducing Clostridia proved to be complete. Giardia and Cryptosporidium removal should be equal to this removal efficiency. For direct cell counts and heterotrophic plate counts a lower efficiency was found. Probably this is due to regrowth on the permeate side of the reverse osmosis installation. In the second system, indicator organisms E-Coli and spores of sulphite Reducing clostridia present in CSF treated Yssel Lake water were reduced after ultrafiltration to values below the detection limit. Generally ultrafiltration showed a complete (>5-log) removal of MS02 phages. After an introduced leakage of 0.2% removal was 2.7-log units only. Ultra low pressure reverse osmosis showed a high (4.7-4.9-log) although no complete removal. In the second system, integrity of the ultrafiltration is measured by a pressure hold test and monitored by particle counting. Ultra low pressure reverse osmosis integrity is measured by vacuum testing and in situ conductivity and monitored by particle counting and sulphate removal. Includes 8 references, tables, figures.

Product Details

Edition:

Vol. - No.

Published:

01/01/1999

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1 file , 110 KB