Cubical-Shaped Rods of Pectin–Hydroxyapatite Composite for Adsorption Studies of Fluoride by Statistical Method and Adsorption Experiments

Abstract

This research details the synthesis and application of a novel pectin–hydroxyapatite (PHAp) composite for fluoride (F – ) adsorption from aqueous solutions. To determine the efficiency of the adsorption process parameters, i.e., adsorbent dose (0.1–0.4 g), initial fluoride concentration (10–30 mg/L), and temperature (298–313 K), the Box–Behnken design with three levels and three factors have been utilized. The quadratic model was established on 27 batch runs by regression analysis of the experimental data of these runs. The efficacy of adsorption was observed using the Langmuir and Freundlich models. The adsorption rate was found at 3.17 mg g −1 min –1 , and adsorption kinetics followed pseudo-second order (PSO) for PHAp. The significant novelty of this work is the synthesis of unique cubical-shaped rods biopolymer composite from hydroxyapatite. Additionally, this composite showed high adsorption capacity for F – compared to other hydroxyapatite adsorbents, and the improved adsorption capacity is attributed to its unique shape which provides a larger surface area. It can be reused for up to six cycles, which makes this method environment-friendly. The economic viability of the synthesized PHAp composite, in comparison to other adsorbents, is evident from the cost–benefit analysis.

Hydrothermally Shape-Controlled Synthesis of TiO2/Graphene for Fluoride Adsorption Studies

“…The obtained results are displayed by a bar diagram as shown in Figure a. The promising act of the TiO 2 –GO nanocomposite on the tolerance of coexisting ions is most important for its practical applicability for the treatment of real-world water bodies. , …”

Synergistic Fluoride Adsorption by Composite Adsorbents Synthesized From Different Types of Materials—A Review

“…Due to its unique crystal structure, HAp has a porous surface, large specific surface area, and high ion exchange capacity. The hydroxyl group in HAp is prone to rapid exchange with anion and has a strong binding capacity with fluoride ( Raghav et al, 2018 ). F − replaces OH − , fills in the lattice of HAp forming insoluble fluorapatite (FAp), and OH − is released into solution.…”

An innovative Azadirachta indica gum‐mediated synthesis of cocoon‐shaped nano‐AgHAp from Lamellidens marginalis shells

“…In this study, it is aimed to develop HAp nanoparticles using Lamellidens marginalis shells as a calcium source through extraction method. The naturally available AI gum was employed as a medium to control the size and shape of the HAp and AgHAp nanoparticles 32–35 . The synthesized HAp nanoparticles were further characterized using various characterization techniques to evaluate their surface and biological behavior.…”

“…The naturally available AI gum was employed as a medium to control the size and shape of the HAp and AgHAp nanoparticles. [32][33][34][35] The synthesized HAp nanoparticles were further characterized using various characterization techniques to evaluate their surface and biological behavior.…”