Potentiometric Study of Aluminium-Fluoride Complexation Equilibria and Definition of the Thermodynamic Model

Corbillón, M. Soledad; Olazabal, María Ángeles; Madariaga, Juan Manuel

doi:10.1007/s10953-008-9257-3

Cited by 39 publications

(33 citation statements)

References 17 publications

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“…And fluoride removal is strongly dependent on pH, so pH adjustment is often applied in practice [2]. The variation of pH influences the transformation of both Al and fluoride species [5][6][7]. In previous studies about fluoride removal only total fluoride was determined and variation of free fluoride was ignored.…”

Section: Introductionmentioning

confidence: 99%

Effect of aluminum fluoride complexation on fluoride removal by coagulation

Gong¹,

Qu²,

Liu³

et al. 2012

Colloids and Surfaces A: Physicochemical and Engineering Aspect

128

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a b s t r a c tEffect of aluminum fluoride complexation on fluoride removal by Al salts coagulation was investigated by a series of batch experiments. Transformation of fluoride species in coagulation was studied by simultaneous determination of free fluoride and total fluoride at different pH and fluoride concentrations. Results showed that aluminum fluoride complexes dominated at low pH and high fluoride concentrations but more complexes did not represent higher fluoride removal. Comparison between coagulation with complexation and adsorption by Al(OH) 3 flocs was conducted and coagulation showed higher fluoride removal efficiency than adsorption in the pH range of 6.0-9.0. Titration test showed that Al F complexes were coprecipitated with less OH − than Al 3+ . Characterization of FTIR and XPS also indicated that flocs after complexation was different from Al(OH) 3 flocs with or without fluoride. It was concluded that a new Al F OH coprecipitate formed in coagulation and fluoride was effectively removed by the coprecipitation.

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Section: Introductionmentioning

confidence: 99%

Effect of aluminum fluoride complexation on fluoride removal by coagulation

Gong¹,

Qu²,

Liu³

et al. 2012

Colloids and Surfaces A: Physicochemical and Engineering Aspect

128

View full text Add to dashboard Cite

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“…Corbillon et al reported that initial fluoride concentrations as expressed by [F] 0 strongly affected the interactions between aluminum and fluoride [34]. transformation of fluoride and aluminum accordingly [13].…”

Section: Effect Of Fluoride On Coagulants Towards Fluoridementioning

confidence: 99%

Coagulation behaviors of aluminum salts towards fluoride: Significance of aluminum speciation and transformation

Lan

Gong

et al. 2016

Separation and Purification Technology

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a b s t r a c tThis study investigates the effects of aluminum (Al) and F interactions on the coagulation behaviors of Al salts, i.e., AlCl 3 and polymer aluminum chloride (PACl) at different basicity (B) towards fluoride. These coagulants achieve the optimum fluoride removal over pH 6-7, and PACl exhibits higher removal efficiency than AlCl 3 does over pH 4-9. The removal of fluoride is positively correlated with the content of either Al 13 or Al b in Al-based coagulants over pH 4-9 and increases in the order: PACl 2 > PACl 1 > AlCl 3 . As for PACl, the increased B from 0 to 2.4 improves fluoride removal owing to the elevated ratios of Al b . However, at further increased B to 2.8, the formation of colloidal Al species

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“…The rate of aluminum fluoride complexation is observed to be highly dependent on pH (Neal, 1995), and the formation of hydrolyzed Al(III) species (i.e., Al(H 2 O) 5 (OH) 2+ ) at pH above 4.5 significantly increases the complexation rate (Plankey et al, 1988). As indicated by potentiometric study and thermodynamic modeling, the Al-F complexes' speciation is rather complicated and their species distribution is highly dependent on pH, fluoride concentrations, and ionic strength (Corbillon et al, 2008). The ratios of complexed fluoride to total fluoride were observed to be strongly dependent on solution pH and the molar ratios of F to Al (R F:Al ) (Gong et al, 2012).…”

Section: Introductionmentioning

confidence: 99%