title: Modification of low pressure membranes with carbon nanotube layers for fouling control.
abstract: Carbon nanotubes (CNTs) with different physiochemical properties were layered onto low pressure membranes and tested for antifouling properties using a natural surface water with high fouling potential. Membranes modified with the largest diameter pristine multi-walled CNTs (MWCNTs) were most effective in controlling membrane fouling, tripling the time it took for the membrane to become noticeably fouled at a CNT loading of 22 g/m(2). The differences in the structure of CNT layers were an important contributing factor for antifouling properties; scanning electron microscopy imaging showed that large diameter MWCNTs formed homogeneous porous layers across the membrane surface, while less effective, small diameter MWCNTs formed heterogeneous layers. Water quality analysis showed that CNT-membranes constructed with larger diameter CNTs were more effective at removing larger organic macromolecules responsible for fouling from feedwater compared to membranes made with smaller diameter CNTs. This reduced the concentration of foulants reaching the PVDF membrane and thus helped reduce membrane fouling. Beneficial for application, increased loadings of CNTs onto the membrane surface increased resistance to fouling while only slightly reducing the clean water permeability of the modified membranes. Overall, CNT layered membranes were shown to highly resist membrane fouling with potential applications in sustainable water treatment.
authors.affiliation: Center for Water and Health, Johns Hopkins University, Baltimore, MD 21205, USA.
authors.forename: Gaurav S
authors.initials: GS
authors.lastname: Ajmani
authors.affiliation: Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218, USA.
authors.forename: David
authors.initials: D
authors.lastname: Goodwin
authors.affiliation: Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218, USA.
authors.forename: Kristofer
authors.initials: K
authors.lastname: Marsh
authors.affiliation: Department of Chemistry, Johns Hopkins University, Baltimore, MD 21218, USA.
authors.forename: D Howard
authors.initials: DH
authors.lastname: Fairbrother
authors.affiliation: Center for Water and Health, Johns Hopkins University, Baltimore, MD 21205, USA.
authors.forename: Kellogg J
authors.initials: KJ
authors.lastname: Schwab
authors.affiliation: Center for Water and Health, Johns Hopkins University, Baltimore, MD 21205, USA; MWH, Lovettsville, VA 20180, USA.
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Jacangelo
authors.affiliation: Center for Water and Health, Johns Hopkins University, Baltimore, MD 21205, USA. Electronic address: haiouh@jhu.edu.
authors.forename: Haiou
authors.initials: H
authors.lastname: Huang
mesh_terms: D002606:Charcoal / Q000737:chemistry; D008567:Membranes, Artificial; D037742:Nanotubes, Carbon / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D008567:Membranes, Artificial; D037742:Nanotubes, Carbon; D002606:Charcoal