Optimization of Fluoride Adsorption on Acid Modified Bentonite Clay Using Fixed-Bed Column by Response Surface Method

Abstract

Using small-scale batch tests, various researchers investigated the adsorptive removal of fluoride using low-cost clay minerals, such as Bentonite. In this study, Column adsorption studies were used to investigate the removal of fluoride from aqueous solution using acid-treated Bentonite (ATB). The effects of initial fluoride concentration, flow rates, and bed depth on fluoride removal efficiency (R) and adsorption capability (qe) in continuous settings were investigated, and the optimal operating condition was determined using central composite design (CCD). The model’s suitability was determined by examining the relationship between experimental and expected response values. The analysis of variance was used to determine the importance of independent variables and their interactions. The optimal values were determined as the initial concentration of 5.51 mg/L, volumetric flow rate of 17.2 mL/min and adsorbent packed-bed depth of 8.88 cm, with % removal of 100, adsorptive capacity of 2.46 mg/g and desirability of 1.0. This output reveals that an acid activation of Bentonite has made the adsorbent successful for field application.

Sodium Alginate/Modified Bentonite Composite Bead Adsorptive Removal of Norfloxacin: Static and Dynamic Adsorption

“…Bentonite, a clay mineral, has the advantages of low cost and high cation exchange capacity, which is favorable for adsorption [ 17 , 18 ]. It also has the characteristics as with other nature clays, such as a crystalline structure and a limited variety of functional groups [ 19 ].…”

Adsorption Characteristics and Charge Transfer Kinetics of Fluoride in Water by Different Adsorbents

“…Similar to diatomite, bentonite is a clay mineral, whose main component is montmorillonite, which has a large surface area and strong adsorption capacity and is abundant in nature. Studies on the use of bentonite or modified bentonite for fluoride removal from water bodies have also been reported, for which good adsorption results are reported ( Fang et al, 2016 ; Kalsido et al, 2021 ). Biochar is a typical carbon-based adsorbent obtained by high-temperature pyrolysis of waste biomass in an anaerobic environment.…”