Removal of Fluoride from Aqueous Solution Using Aluminum Alginate Beads

Abstract

Fluoride is a contaminant in groundwater; hence numerous procedures for its removal are reported. Adsorption studies are specified as effective methods for removal of fluoride contamination from water sources. In the present study, aluminum crosslinked alginate beads are used as an adsorbent for fluoride removal from aqueous solutions. Adsorption experiments were carried out by batch contact method. The equilibrium was achieved in 4 h. Optimal conditions were found to be pH 2 at 25°C, giving rise to 99.5% removal of fluoride. Various kinetic (pseudo-first and -second order, intraparticle diffusion, and Elovich) and isotherm [Langmuir, Freundlich, Dubinin-Radushkevich (D-R), and Temkin] models were applied to the adsorption data. The maximum adsorption capacity was determined as 75.2 mg/g from the Langmuir isotherm. The value of mean sorption energy was calculated as 2.75 kJ/mol (<8 kJ/mol) from the D-R isotherm, which indicates a physical adsorption. Thermodynamic parameters were also calculated and negative DG values were related to a spontaneous nature of the adsorption. This study suggests that aluminum alginate beads can be used as efficient, cheap and eco-friendly adsorbents for the removal of fluoride from contaminated water.

Batch and column adsorption of cations, oxyanions and dyes on a magnetite modified cellulose-based membrane

“…the Ho-McKay model, the second-order rate and the Roginsky-Zeldovich-Elovich equation, Eqs. (S12)-(S18), respectively, applying both linear and nonlinear least-squares methods (Kaygusuz et al 2015). The best correlation was obtained using non-linear fitting with PSO equation (Table S11).…”

New Approach to Remove Heavy Metals from Wastewater by the Coagulation of Alginate-Rhamnolipid Solution with Aluminum Sulfate

“…Alginate solution (4% w/v) was mixed with a rhamanolipid solution (0.1% w/v) at 80 • C for 2 h, and then a copper standards solution was put into the mixture (Figure 1) [24][25][26][27]. A small amount of copper standard solution, 5 mL of 100 mg/L, was adopted for this preliminary study.…”

A simple one-pot in-situ method for the synthesis of aluminum and lanthanum binary oxyhydroxides in chitosan template towards defluoridation of water

“…A number of studies were reported for the removal of fluoride using chitosan biopolymer based sorbents, lanthanum entrapped chitosan composite [5], zirconium encapsulated chitosan matrix [6], lanthanum-zirconium chitosan composite [7], hydrous ferric oxide doped alginate beads [8], Fe(III)-Zr(IV) binary oxide loaded calcium alginate beads [9], aluminium loaded alginate beads [10], metal loaded carboxylated alginate acid [11] etc. Similarly, aluminium and lanthanum modified adsorbents showed higher defluoridation capacity due to their high selectivity and chemical affinity towards fluoride than the respective bare alumina and lanthanum.…”