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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.

Biogenic amines in wine samples and pomegranate molasses were detected and quantified by a nonionic micellar electrokinetic chromatography method coupled to laser-induced fluorescence detection. The method provides a satisfactory and fast separation of seven biogenic amines and matrix peaks in food samples in less than 9 min. Detection limits are between 0.42 and 1.26 nM, and precisions were lower than 3% RSD for peak areas. The recovery values were between 93% and 104%, depending on the food matrix. The method is sensitive and rapid and widely applicable for the determination of biogenic amines in wine samples and fruit molasses.

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