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The primary goal of this AwwaRF funded research was to investigate the impact and contributionof natural organic matter (NOM) fouling using vendor-supplied proprietary units from membranemanufacturers on specific natural water supplies. Interactions between water quality, pretreatmentchemicals, membrane materials, and membrane configurations were tested at pilot-scale withvarious operating conditions. Pilot studies were conducted with Zenon's Zee-Weed 1000 pilot unitwith immersed membranes at the Tampa Bay Regional Water Treatment Plant, utilizing raw andcoagulated waters as feed. The unit was equipped with 0.02 m PVD hollow fiber membranes.The pilot testing program was designed to distinguish between three types of NOM-based fouling:hydraulically reversible fouling, chemically reversible fouling, and irreversible fouling. Membranefiltration cycle was evaluated through quantification of membrane flux decline rates. Chlorineoxidation was more effective in reversing the effect of NOM fouling of the Zeeweed PVDFmembrane compared with the acid and caustic. Runs that utilized lowered recovery or phosphoricacid chemical wash showed a reduction in membrane fouling compared to coagulated waterbaseline runs. HPSEC analyses revealed that high molecular weight compounds (10k-30k Daltons)were rejected or adsorbed by the ZeeWeed 1000 PVDF membrane as indicated by the decreasedconcentration of these compounds in the permeate. Backwash samples showed an elevated responseof the high molecular weight compounds, indicating that these compounds were hydraulicallydisplaced from the membrane or with the foulant layer. Data from 3-D fluorescence excitationemission matrices supported this trend. Includes 6 references, tables, figures.

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Edition: Vol. - No. Published: 11/01/2005 Number of Pages: 20File Size: 1 file , 640 KB