The use of membrane technology and, in particular, microfiltration (MF) is
becoming more popular as a water treatment technology. The potential
lifetime of MF can be reduced by natural organic matter (NOM) which is a
known foulant to these membranes. The MIEX dissolved organic carbon (DOC) process was developed
to remove NOM from raw water sources. It is anticipated that the reduction in
NOM resulting from the MIEX DOC process would also improve the
performance of MF systems. A pilot plant study was undertaken to directly
measure the impact of MIEX pretreatment on MF performance. A single module continuous microfiltration - suspended (CMF-S) membrane
pilot plant was provided on lease from Veolia Water. The unit
incorporated a suspended S10V membrane module supplied by Memcor. The S10V module
consists of 14,000 hollow fiber filaments made from PVDF polymer with a
nominal pore size of 0.04µm. The module's fresh weight was 6.7kgs and it is
capable of withstanding 200ppm of free chlorine.
It was necessary to produce MF treated water from MIEX and raw source
waters, using two modules in a staggered parallel mode. One
membrane was stored in a refrigerator in chlorinated WTP treated water when
not in use. During the change over, the membranes were rinsed with WTP
treated water. Some programmable logic controller modification was required
to allow the membrane to run in staggered parallel fashion.
The rig was operated at 1000L/hr flow rate (39.5L/hr/m<sup>2</sup> flux rate) and was
backwashed by air scour every 45 minutes. A weekly pressure decay test was
performed to detect any broken membrane fibers. A clean-in-place (CIP) was
conducted after 600 hours of operation of each module which involved a 3 hour
recycling and soaking cycle at pH 2 with 4g of EDTA at 40ºC.
Fouling of the membranes was determined using the resistance, a value
calculated from the transmembrane pressure (TMP). Includes 5 references, figures.
| Edition : | Vol. - No. |
| File Size : | 1
file
, 930 KB |
| Note : | This product is unavailable in Ukraine, Russia, Belarus |
| Number of Pages : | 8 |
| Published : | 11/01/2008 |
