title: Directing carbon nanotubes from aqueous phase to o/w interface for heavy metal uptaking.
abstract: Separation and reuse of dispersed nanoparticles are major obstacles to the extensive application of nano-sized absorbents in wastewater treatment. Herein, we demonstrate the capability of directing acid-oxidized carbon nanotubes (CNTs) as the transfer vehicles of heavy metal ions from simulated wastewater. The heavy metal-loaded CNTs can be readily separated from the aqueous phase via the aggregation process at an oil/water (o/w) interface. The minimum surfactant amount to achieve 99 % transfer ratio (Tr) of 100 mg/L CNTs from water phase to o/w interface was ∼0.01 mM. The adsorption experiments showed that the removal efficiency of the divalent lead ions increased with an increase in CNT mass, and the subsequent addition of cetyltrimethylammonium bromide (CTAB) surfactant did not negatively impact the removal of soluble divalent lead species (Pb(II)). In a wide region of pH and ionic strength, both the decontamination of Pb(II) and the transfer of CNTs from water phase to o/w interface can be accomplished successively. The method presented in this study may be developed as a generic one for collecting or recycling the pollutant-loaded nano-sized absorbents.
authors.affiliation: School of Resource and Environmental Science, Wuhan University, Wuhan, 430072, People's Republic China.
authors.forename: Lili
authors.initials: L
authors.lastname: Gao
authors.forename: Huayi
authors.initials: H
authors.lastname: Yin
authors.forename: Xuhui
authors.initials: X
authors.lastname: Mao
authors.forename: Hua
authors.initials: H
authors.lastname: Zhu
authors.forename: Wei
authors.initials: W
authors.lastname: Xiao
authors.forename: Dihua
authors.initials: D
authors.lastname: Wang
mesh_terms: D000327:Adsorption; D000077286:Cetrimonium; D002593:Cetrimonium Compounds / Q000737:chemistry; D007854:Lead / Q000737:chemistry* / Q000302:isolation & purification; D037742:Nanotubes, Carbon / Q000737:chemistry*; D009821:Oils / Q000737:chemistry*; D009994:Osmolar Concentration; D010084:Oxidation-Reduction; D059027:Recycling; D062065:Wastewater / Q000737:chemistry; D014867:Water / Q000737:chemistry*; D014874:Water Pollutants, Chemical / Q000737:chemistry* / Q000302:isolation & purification; D018508:Water Purification
chemical_list: D000077286:Cetrimonium; D002593:Cetrimonium Compounds; D007854:Lead; D037742:Nanotubes, Carbon; D009821:Oils; D062065:Wastewater; D014867:Water; D014874:Water Pollutants, Chemical