title: Effects of ozone and peroxone on algal separation via dispersed air flotation.
abstract: Effects of pre-oxidation on algal separation by dispersed air flotation were examined. Ozone (O3) and peroxone (O3 and H2O2) could induce cell lysis, release of intracellular organic matter (IOM), and mineralization of organic substances. Separation efficiency of algal cells improved when pre-oxidized. Total of 76.4% algal cells was separated at 40 mg/L of N-cetyl-N-N-N-trimethylammonium bromide (CTAB), while 95% were separated after 30-min ozonation. Pre-oxidation by ozone and peroxone also enhanced flotation separation efficiency of dissolved organic carbon (DOC), polysaccharide, and protein, in which peroxone process exerted more significantly than O3. Two main mechanisms were involved in flotation separation of unoxidized algal suspension, namely hydrophobic cell surface and cell flocculation resulting from CTAB adsorption. However, flocculation by CTAB was hindered for pre-oxidized algal suspensions. It implied that the compositional changes in extracellular organic matter (EOM) by pre-oxidation were more determined for flotation separation of pre-oxidized cells.
authors: Department of Chemical Engineering, National Taiwan University of Science and Technology, Taipei 106, Taiwan.
authors: Truc Linh
authors: TL
authors: Nguyen
authors: D J
authors: DJ
authors: Lee
authors: J S
authors: JS
authors: Chang
authors: J C
authors: JC
authors: Liu
mesh_terms: D000388:Air; D002708:Chlorella / Q000302:isolation & purification*; D005427:Flocculation; D006861:Hydrogen Peroxide / Q000737:chemistry*; D010084:Oxidation-Reduction; D010126:Ozone / Q000737:chemistry*; D014865:Waste Disposal, Fluid; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods*
chemical_list: D014874:Water Pollutants, Chemical; D010126:Ozone; D006861:Hydrogen Peroxide