title: Cleaning strategies for flux recovery of an ultrafiltration membrane fouled by natural organic matter.
abstract: One of the most common problems encountered in water treatment applications of membranes is fouling. Natural organic matter (NOM) represents a particularly problematic foulant. Membranes may be fouled by relatively hydrophilic and/or hydrophobic NOM components, depending on NOM characteristics, membrane properties, and operating conditions. To maximize flux recovery for an NOM-fouled ultrafiltration membrane (NTR 7410), chemical cleaning and hydraulic rinsing with a relatively high cross-flow velocity were investigated as cleaning strategies. The modification of the membrane surface with either an anionic or a cationic surfactant was also evaluated to minimize membrane fouling and to enhance NOM rejection. Foulants from a hydrophobic NOM source (Orange County ground water (OC-GW)) were cleaned more effectively in terms of permeate flux by acid and caustic cleanings than foulants from a relatively hydrophilic NOM source (Horsetooth surface water (HT-SW)). An anionic surfactant (sodium dodecyl sulfate (SDS)) was not effective as a cleaning agent for foulants from either hydrophobic or hydrophilic NOM sources. High ionic strength cleaning with 0.1 M NaCl was comparatively effective in providing flux recovery for NOM-fouled membranes compared to other chemical cleaning agents. Increased cross-flow velocity and longer cleaning time influenced the efficiency of caustic cleaning, but not high ionic strength cleaning. The membrane was successfully modified only with the cationic surfactant; however, enhanced NOM rejection was accompanied by a significant flux reduction.
authors.affiliation: Department of Environment Sciences & Engineering, Kwangju Institute of Science and Technology, South Korea.
authors.forename: H
authors.initials: H
authors.lastname: Lee
authors.forename: G
authors.initials: G
authors.lastname: Amy
authors.forename: J
authors.initials: J
authors.lastname: Cho
authors.forename: Y
authors.initials: Y
authors.lastname: Yoon
authors.forename: S H
authors.initials: SH
authors.lastname: Moon
authors.forename: I S
authors.initials: IS
authors.lastname: Kim
mesh_terms: D000143:Acids / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D008567:Membranes, Artificial; D008851:Micropore Filters; D009930:Organic Chemicals / Q000737:chemistry / Q000302:isolation & purification*; D009994:Osmolar Concentration; D013501:Surface-Active Agents / Q000737:chemistry; D013997:Time Factors; D014462:Ultrafiltration / Q000379:methods*; D018508:Water Purification / Q000379:methods*
chemical_list: D000143:Acids; D008567:Membranes, Artificial; D009930:Organic Chemicals; D013501:Surface-Active Agents