title: Electrochemical removal of fluoride from water by PAOA-modified carbon felt electrodes in a continuous flow reactor.
abstract: A novel poly(aniline-co-o-aminophenol) (PAOA) modified carbon felt electrode reactor was designed and investigated for fluoride removal from aqueous solutions. This reactor design is innovative because it operates under a wider pH range because of coating with a copolymer PAOA ion exchange film. In addition, contaminant mass transfer from bulk solution to the electrode surface is enhanced by the porous carbon felt as an electron-conducting carrier material compared to other reactors. The electrically controlled anion exchange mechanism was investigated by X-ray photoelectron spectroscopy and cyclic voltammetry. The applicability of the reactor in the field was tested through a series of continuous flow experiments. When the flow rate and initial fluoride concentration were increased, the breakthrough curve became sharper, which lead to a decrease in the breakthrough time and the defluoridation capacity of the reactor. The terminal potential values largely influenced fluoride removal by the reactor and the optimal defluoridation efficiency was observed at around 1.2V. The breakthrough capacities were all >10mg/g over a wide pH range (pH 5-9) with an initial fluoride concentration of 10mg/L. Consecutive treatment-regeneration studies over a week (once each day) revealed that the PAOA-modified carbon felt electrode could be effectively regenerated for reuse. The PAOA-modified carbon felt electrode reactor is a promising system that could be made commercially available for fluoride removal from aqueous solutions in field applications.
authors.affiliation: State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing 210093, PR China.
authors.forename: Hao
authors.initials: H
authors.lastname: Cui
authors.forename: Yan
authors.initials: Y
authors.lastname: Qian
authors.forename: Hao
authors.initials: H
authors.lastname: An
authors.forename: Chencheng
authors.initials: C
authors.lastname: Sun
authors.forename: Jianping
authors.initials: J
authors.lastname: Zhai
authors.forename: Qin
authors.initials: Q
authors.lastname: Li
mesh_terms: D000627:Aminophenols / Q000737:chemistry*; D002244:Carbon / Q000737:chemistry*; D004566:Electrodes; D005459:Fluorides / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D056951:Photoelectron Spectroscopy; D014867:Water / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*
chemical_list: D000627:Aminophenols; C522165:poly(aniline-co-o-aminophenol); D014867:Water; D002244:Carbon; D005459:Fluorides