Full Description

The use of membrane technology and, in particular, microfiltration (MF) isbecoming more popular as a water treatment technology. The potentiallifetime of MF can be reduced by natural organic matter (NOM) which is aknown foulant to these membranes. The MIEX dissolved organic carbon (DOC) process was developedto remove NOM from raw water sources. It is anticipated that the reduction inNOM resulting from the MIEX DOC process would also improve theperformance of MF systems. A pilot plant study was undertaken to directlymeasure the impact of MIEX pretreatment on MF performance. A single module continuous microfiltration - suspended (CMF-S) membranepilot plant was provided on lease from Veolia Water. The unitincorporated a suspended S10V membrane module supplied by Memcor. The S10V moduleconsists of 14,000 hollow fiber filaments made from PVDF polymer with anominal pore size of 0.04m. The module's fresh weight was 6.7kgs and it iscapable of withstanding 200ppm of free chlorine.It was necessary to produce MF treated water from MIEX and raw sourcewaters, using two modules in a staggered parallel mode. Onemembrane was stored in a refrigerator in chlorinated WTP treated water whennot in use. During the change over, the membranes were rinsed with WTPtreated water. Some programmable logic controller modification was requiredto allow the membrane to run in staggered parallel fashion.The rig was operated at 1000L/hr flow rate (39.5L/hr/msup2/sup flux rate) and wasbackwashed by air scour every 45 minutes. A weekly pressure decay test wasperformed to detect any broken membrane fibers. A clean-in-place (CIP) wasconducted after 600 hours of operation of each module which involved a 3 hourrecycling and soaking cycle at pH 2 with 4g of EDTA at 40C.Fouling of the membranes was determined using the resistance, a valuecalculated from the transmembrane pressure (TMP). Includes 5 references, figures.

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Edition: Vol. - No. Published: 11/01/2008 Number of Pages: 8File Size: 1 file , 930 KB