Electrochemical removal of fluoride ions from industrial wastewater

Feng Shen, Xueming Chen, Ping Gao, Guohua Chen

Research output: Journal article publicationJournal articleAcademic researchpeer-review

350 Citations (Scopus)

Abstract

Fluoride ions were removed electrochemically from a solution using a combined electrocoagulation and electroflotation process. For an influent fluoride concentration of 15 mg/l, a value after lime precipitation, the effluent fluoride concentration can be lower than 2 mg/l when the pH in the coagulation cell is around 6, charge loading is at 4.97 F/m3water, and the residence time is 20 min. Even lower effluent concentration can be achieved if 50 mg/l of Fe3+or Mg2+are added into the coagulation unit. The anions generally reduce the fluoride removal efficiency except Cl-whose corrosion pitting of the electrode can result in 130% current efficiency. The composition of the sludge produced from the operation was analyzed using X-ray photoelectron spectroscopy (XPS) and time-of-flight secondary ion mass spectroscope system (ToF-SIMS). The characterization results show that the defluorination is a chemical adsorption process with F-replacing the -OH group from the Aln(OH)3nflocs.
Original languageEnglish
Pages (from-to)987-993
Number of pages7
JournalChemical Engineering Science
Volume58
Issue number3-6
DOIs
Publication statusPublished - 1 Jan 2003
Externally publishedYes

Keywords

  • Adsorption
  • Electrocoagulation
  • Environment
  • Flotation
  • Pollution
  • Sludge

ASJC Scopus subject areas

  • Chemistry(all)
  • Chemical Engineering(all)
  • Industrial and Manufacturing Engineering

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