This paper presents a study on the development and validation of a laboratory-scale
membrane testing protocol to select viable membranes for pilot- and full-scale operation.
This selection protocol balanced operational characteristics (such as pressure, flux and
potential for fouling) with product water quality and allowed for a pre-selection of
potentially viable candidate membranes. Membranes considered for selection were
characterized as thin-film composite (TFC) polyamide membranes and included
commercially available ULPRO (TFC-ULP, Koch Membrane Systems; XLE,
Dow/Filmtec; TMG10, Toray America; RE-BLR, Saehan) and nanofiltration (NF) membrane products
(NF-90, NF-270, NF-200 and NF-4040, Dow/Filmtec; TFC-S, Koch Membrane Systems;
ESNA1-LF, Hydranautics; MX07, Osmonics; NE-90, Saehan).
Three candidate membranes were selected and tested using a 68 L/min (18 gpm)
membrane pilot skid that was designed, constructed and operated during this study. The
three selected candidate membranes were each tested for at least 1,300 hours on
microfiltered feed water at two full-scale facilities. The different feed waters represented
non-nitrified microfiltered effluent provided by the West Basin Water Recycling Plant
(WBWRP) in El Segundo, CA and nitrified/denitrified microfiltered effluent provided by
the Scottsdale Water Campus (SWC), Arizona. Operational performance and rejection of trace organics, nutrients and total organic carbon were monitored during pilot-scale testing and
compared to the performance of full-scale trains operating on the same feedwater
employing conventional RO membranes (i.e., TFC-HR, Koch Membrane Systems and
ESPA2, Hydranautics). During several occasions, challenge tests were conducted at pilot-scale
to examine rejection of trace organics during periods of elevated feed
concentrations. The best performing ULPRO membrane was also selected for testing over
5,000 hours in a 6.6 m<sup>3</sup>/min (2.5-mgd) full-scale reverse osmosis (RO) train to further verify findings from
pilot-scale and to determine rejection behavior and operating costs under full-scale
conditions.
The study was assisted through state-of-the-art membrane characterization to
describe the fouling character of NF/ULPRO membranes and its role on operation (e.g.,
flux decline) and rejection. A comprehensive membrane autopsy was performed after
each pilot-scale testing period to determine the nature of the observed flux decline and
characterize the type and location of fouling. Includes 12 references, tables, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 740 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 10 |
| Published : | 03/01/2007 |
