Full Description

Nanofiltration (NF) was evaluated as a polishing process to remove algal toxins, taste and odor compounds, and disinfection byproduct precursors from a conventionally treated Florida surface water. Bench-scale tests were conducted using water samples collected following treatment by enhanced coagulation, sedimentation, and dual media filtration, but before chloramination. Samples were spiked with 10 ug/L of microcystin-LR and approximately 50 ng/L each of geosmin and 2-methylisoborneol (MIB) to evaluate nanofiltration removal of these compounds. In addition, 70 percent recovery permeates were tested for formation potential of trihalomethanes (THMFP) and haloacetic acids (HAA6FP). NF membranes achieved excellent removals of microcystin (82 to 99 %). Feed water geosmin levels of 47 to 70 ng/L were reduced 9 to 98%, and feedwater MIB concentrations of 46 to 77 ng/L were reduced 17 to 96%. NF membranes achieved TOC reductions of 80 to 96 percent at 70% recovery, as well as 43 to 95 percent THMFP reduction and 84 to 97 % HAA6FP reduction. The results of these bench scale tests suggest that NF membrane treatment has the potential to remove microcystin-LR to below the World Health Organization (WHO) Guideline of 1.0 ug/L. Includes 15 references, tables, figures.

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Edition: Vol. - No. Published: 11/01/2002 Number of Pages: 9 File Size: 1 file , 280 KB