title: Effect of coagulation mechanisms on the fouling and ultrasonic cleaning of PTFE membrane.
abstract: In this study, the effect of coagulation pretreatment on membrane fouling and ultrasonic cleaning efficiency was investigated using a dead-end polytetrafluoroethylene (PTFE) microfiltration system. The extent of membrane fouling was examined under different coagulation mechanisms such as charge neutralization (CN), electrostatic patch effect (EPE) and sweep flocculation (SW). Fouling through EPE mechanism provided the greatest flux decline and least permeate flux recovery over CN and SW. EPE produces more stable, smaller and more compact flocs while CN and SW have large, easily degraded and highly-branched structured flocs. The predominant fouling mechanism of EPE, CN and SW is pore blocking, a combination of pore blocking and cake formation, and cake formation, respectively. Better permeate flux recovery is observed with SW over CN and EPE, which implies formation of less dense and more porous cake deposits. The morphology of fouled membranes was examined using scanning electron microscopy (SEM).
authors.affiliation: Department of Environmental Engineering and Science, Chia Nan University of Pharmacy and Science, Tainan, Taiwan.
authors.forename: Meng-Wei
authors.initials: MW
authors.lastname: Wan
authors.forename: Cybelle Morales
authors.initials: CM
authors.lastname: Futalan
authors.forename: Cheng-Hung
authors.initials: CH
authors.lastname: Chang
authors.forename: Chi-Chuah
authors.initials: CC
authors.lastname: Kan
mesh_terms: D057219:Biofouling / Q000517:prevention & control; D002712:Chlorides; D005290:Ferric Compounds; D005427:Flocculation; D008567:Membranes, Artificial; D008855:Microscopy, Electron, Scanning; D011138:Polytetrafluoroethylene; D013016:Sound; D013242:Sterilization
chemical_list: D002712:Chlorides; D005290:Ferric Compounds; D008567:Membranes, Artificial; D011138:Polytetrafluoroethylene; C024555:ferric chloride