Abstract
Tetrafluoroborate anion (BF4−) is found in the streams of flue-gas desulfurization and borosilicate glasses etching which deteriorates water quality through slow hydrolysis into boric acid and fluoride. Decomposition and electrocoagulation (EC) of BF4− were studied using metallic aluminum as the sacrificial electrode. The dissolved Al(III) from the anode could efficiently decompose BF4− in forms of fluoroaluminate complexes, and the derived boric acid and fluoride ion were removed by sweep flocculation. Major variables were investigated to optimize EC, including the reaction pH, initial concentration of BF4−, current density and electrolyte type. The mechanism of EC process was elucidated with the kinetics of consecutive reactions. Experimental results suggested that the removal of BF4− and total fluoride were less influenced by pH, and that of total boron reached a maximum at pH 8 which favored the surface complexation between borate species and EC precipitates. Under the conditions: [BF4−]0 = 9.3 mM, [NaCl] = 10 mM, pH = 8.0, current density = 5 mA/cm2, 98.3% of BF4− was decomposed and the removal of total fluoride and boron attained 98.2% and 74.1%, respectively within 3 h. EC using the Al electrode outperformed the conventional chemical coagulation and reduced the levels of BF4–], B(OH)3 and F− in aqueous solution synergically.
| Original language | English |
|---|---|
| Pages (from-to) | 362-371 |
| Number of pages | 10 |
| Journal | Water Research |
| Volume | 155 |
| DOIs | |
| Publication status | Published - 2019 May 15 |
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All Science Journal Classification (ASJC) codes
- Ecological Modelling
- Water Science and Technology
- Waste Management and Disposal
- Pollution
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Electrocoagulation of tetrafluoroborate (BF4−) and the derived boron and fluorine using aluminum electrodes. / Lin, Jui Yen; Raharjo, Agnes; Hsu, Li Hsin; Shih, Yu Jen; Huang, Yao Hui.
In: Water Research, Vol. 155, 15.05.2019, p. 362-371.Research output: Contribution to journal › Article
TY - JOUR
T1 - Electrocoagulation of tetrafluoroborate (BF4−) and the derived boron and fluorine using aluminum electrodes
AU - Lin, Jui Yen
AU - Raharjo, Agnes
AU - Hsu, Li Hsin
AU - Shih, Yu Jen
AU - Huang, Yao Hui
PY - 2019/5/15
Y1 - 2019/5/15
N2 - Tetrafluoroborate anion (BF4−) is found in the streams of flue-gas desulfurization and borosilicate glasses etching which deteriorates water quality through slow hydrolysis into boric acid and fluoride. Decomposition and electrocoagulation (EC) of BF4− were studied using metallic aluminum as the sacrificial electrode. The dissolved Al(III) from the anode could efficiently decompose BF4− in forms of fluoroaluminate complexes, and the derived boric acid and fluoride ion were removed by sweep flocculation. Major variables were investigated to optimize EC, including the reaction pH, initial concentration of BF4−, current density and electrolyte type. The mechanism of EC process was elucidated with the kinetics of consecutive reactions. Experimental results suggested that the removal of BF4− and total fluoride were less influenced by pH, and that of total boron reached a maximum at pH 8 which favored the surface complexation between borate species and EC precipitates. Under the conditions: [BF4−]0 = 9.3 mM, [NaCl] = 10 mM, pH = 8.0, current density = 5 mA/cm2, 98.3% of BF4− was decomposed and the removal of total fluoride and boron attained 98.2% and 74.1%, respectively within 3 h. EC using the Al electrode outperformed the conventional chemical coagulation and reduced the levels of BF4–], B(OH)3 and F− in aqueous solution synergically.
AB - Tetrafluoroborate anion (BF4−) is found in the streams of flue-gas desulfurization and borosilicate glasses etching which deteriorates water quality through slow hydrolysis into boric acid and fluoride. Decomposition and electrocoagulation (EC) of BF4− were studied using metallic aluminum as the sacrificial electrode. The dissolved Al(III) from the anode could efficiently decompose BF4− in forms of fluoroaluminate complexes, and the derived boric acid and fluoride ion were removed by sweep flocculation. Major variables were investigated to optimize EC, including the reaction pH, initial concentration of BF4−, current density and electrolyte type. The mechanism of EC process was elucidated with the kinetics of consecutive reactions. Experimental results suggested that the removal of BF4− and total fluoride were less influenced by pH, and that of total boron reached a maximum at pH 8 which favored the surface complexation between borate species and EC precipitates. Under the conditions: [BF4−]0 = 9.3 mM, [NaCl] = 10 mM, pH = 8.0, current density = 5 mA/cm2, 98.3% of BF4− was decomposed and the removal of total fluoride and boron attained 98.2% and 74.1%, respectively within 3 h. EC using the Al electrode outperformed the conventional chemical coagulation and reduced the levels of BF4–], B(OH)3 and F− in aqueous solution synergically.
UR - http://www.scopus.com/inward/record.url?scp=85062468567&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85062468567&partnerID=8YFLogxK
U2 - 10.1016/j.watres.2019.02.037
DO - 10.1016/j.watres.2019.02.037
M3 - Article
C2 - 30856520
AN - SCOPUS:85062468567
VL - 155
SP - 362
EP - 371
JO - Water Research
JF - Water Research
SN - 0043-1354
ER -