title: Sonoelectrochemical mineralization of perfluorooctanoic acid using Ti/PbO 2 anode assessed by response surface methodology.
abstract: BACKGROUND
  Perfluorocarboxylic acids (PFCAs) are emerging pollutant and classified as fully fluorinated hydrocarbons containing a carboxylic group. PFCAs show intensively resistance against chemical and biological degradation due to their strong C-F bond. The Sonoelectrochemical mineralization of the synthetic aqueous solution of the perfluorooctanoic acid (PFOA) on Ti/PbO2 anode was investigated using the response surface methodology based on a central composite design with three variables: current density, pH, and supporting electrolyte concentration.
  
  
  METHODS
  The defluorination ratio of PFOA was determined as an indicator of PFOA mineralization. Fluoride ion concentration was measured with an ion chromatograph unit. The Ti/PbO2 electrode was prepared using the electrochemical deposition method. The ultrasonic frequency was 20 kHz.
  
  
  RESULTS
  The optimum conditions for PFOA mineralization in synthetic solution were electrolyte concentration, pH, and current density of 94 mM, 2, and 83.64 mA/cm(2), respectively. The results indicated that the most effective factor for PFOA mineralization was current density. Furthermore, the PFOA defluorination efficiency significantly enhanced with increasing current density. Under optimum conditions, the maximum mineralization of PFOA was 95.48 % after 90 min of sonoelectrolysis.
  
  
  CONCLUSIONS
  Sonoelectrolysis was found to be a more effective technique for mineralization of an environmentally persistent compound.
authors.affiliation: Environment Research Center and Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences (IUMS), Isfahan, 81676-36954 Iran ; Student Research Center, School of Health, IUMS, Isfahan, Iran.
authors.forename: Gholamreza
authors.initials: G
authors.lastname: Bonyadinejad
authors.affiliation: Nanotechnology Department, University of Isfahan, Isfahan, 81744-73441 Iran.
authors.forename: Mohsen
authors.initials: M
authors.lastname: Khosravi
authors.affiliation: Environment Research Center and Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences (IUMS), Isfahan, 81676-36954 Iran.
authors.forename: Afshin
authors.initials: A
authors.lastname: Ebrahimi
authors.affiliation: Environment Research Center and Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences (IUMS), Isfahan, 81676-36954 Iran.
authors.forename: Roya
authors.initials: R
authors.lastname: Nateghi
authors.affiliation: Research Center for Environmental Pollutants, Qom University of Medical Sciences, Qom, 37136-49373 Iran.
authors.forename: Seyed Mahmood
authors.initials: SM
authors.lastname: Taghavi-Shahri
authors.affiliation: Environment Research Center and Department of Environmental Health Engineering, School of Health, Isfahan University of Medical Sciences (IUMS), Isfahan, 81676-36954 Iran ; Student Research Center, School of Health, IUMS, Isfahan, Iran.
authors.forename: Hamed
authors.initials: H
authors.lastname: Mohammadi
keywords: Central composite design; Lead dioxide; Perfluorooctanoic acid; Ultrasonics