To provide a better and more fundamental understanding of natural organic matter (NOM) fouling of
membranes, a comprehensive study, funded by AwwaRF, was conducted that focused on
characterization of fouling of microfiltration (MF) and ultrafiltration (UF) membranes by three classes or categories of NOM foulants:
allochthonous, represented by humic and fulvic acids; autochthonous or algal-derived; and, effluent
organic matter. Study objectives included identifying problematical NOM
foulants, quantifying the NOM fouling potential of a variety of waters, distinguishing between NOM
fractions that contribute to reversible and irreversible fouling, assessing the properties of membranes
that influence fouling and developing a predictive tool or surrogate test that could be used to measure
the "NOM fouling index" of a given water. The research was conducted by using a combination of
bench, pilot and full-scale tests conducted with a variety of flat-sheet and hollow-fiber MF/UF
membranes. Stirred cell and small-scale hollow fiber bench test apparatuses were evaluated for
fouling prediction and results compared with pilot to assess viability. A variety of analytical methods,
included LC/DOC, XAD resin, AFM, GC/MS pyrolysis and AFM were employed for foulant
characterization in aqueous and solid phases. Bench results show clear differences in fouling potential
by different waters/NOM types, for different membrane materials on a given water and between water
and chemical backwashes. Good correlations were observed between different bench test methods.
Characterization of NOM from raw, filtrate and backwash samples show that polysaccharides and
large MW fraction of NOM is primary fouling constituent, relatively independent of source or NOM
type. The results of this research will provide the drinking water/reuse communities with better
understanding of NOM fouling, effectiveness of membrane materials/properties and
backwashing/chemical washing in managing NOM fouling and value of rapid, bench scale tests in
rapid NOM fouling prediction. This information can be utilized for more cost effective design and
operation of full-scale MF/UF facilities. Includes reference, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 1.3 MB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 20 |
| Published : | 11/01/2005 |
