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Ultrafiltration organic fouling control: Comparison of air‐sparging and coagulation
Author(s) -
Wray Heather E.,
Andrews Robert C.,
Bérubé Pierre R.
Publication year - 2014
Publication title -
journal ‐ american water works association
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.466
H-Index - 74
eISSN - 1551-8833
pISSN - 0003-150X
DOI - 10.5942/jawwa.2014.106.0018
Subject(s) - fouling , sparging , alum , ultrafiltration (renal) , coagulation , chemistry , flocculation , air sparging , membrane fouling , filtration (mathematics) , water treatment , dissolved organic carbon , turbidity , environmental engineering , pulp and paper industry , membrane , chromatography , environmental chemistry , environmental science , environmental remediation , mathematics , psychiatry , ecology , oceanography , contamination , engineering , biology , psychology , biochemistry , statistics , organic chemistry , geology
Air‐sparging and coagulation/flocculation were compared as fouling control strategies during ultrafiltration of surface waters. Fouling was assessed following coagulation (0.5 and 15 mg/L alum) and surface shear stress representative of different air‐sparging conditions: continuous coarse bubble, intermittent coarse bubble, and large pulse bubble. Results indicated that 0.5 mg/L of alum reduced membrane fouling, especially for waters with higher concentrations of organic matter (> 4 mg/L dissolved organic carbon). A 15‐mg/L alum dose did not significantly improve membrane performance relative to the low dose. Air‐sparging reduced fouling, but the benefits were not additive in combination with coagulation. Potential cost savings were calculated based on longer permeation times made possible by reduced fouling, and the value associated with water produced relative to energy costs (air‐sparging) and chemical costs (coagulant). For the water investigated, 0.5 mg/L of alum or large pulse bubble air‐sparging was optimal for membrane fouling control.