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/m3 water, 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)3n flocs. © 2003 Elsevier Science Ltd. All rights reserved.
| Original language | English |
|---|---|
| Pages (from-to) | 987-993 |
| Journal | Chemical Engineering Science |
| Volume | 58 |
| Issue number | 3-6 |
| DOIs | |
| Publication status | Published - Feb 2003 |
| Externally published | Yes |
Bibliographical note
Publication details (e.g. title, author(s), publication statuses and dates) are captured on an “AS IS” and “AS AVAILABLE” basis at the time of record harvesting from the data source. Suggestions for further amendments or supplementary information can be sent to [email protected].Research Keywords
- Adsorption
- Electrocoagulation
- Environment
- Flotation
- Pollution
- Sludge
