Utilization of a constructed nanohydroxyapatite/Arabic gum/alginate composite based on cuttlefish bone for the...

The purpose of this work is to explore the efficacy of cadmium ions (Cd²⁺) removal employing adsorption onto manufactured solid nanomaterials. This study synthesized three nanosolid adsorbents: nanohydroxyapatite based on cuttlefish bone (NHAPs), nanohydroxyapatite/alginate beads (HC), and nanohydroxyapatite/Arabic gum/alginate as triple biocomposite (HGC) beads. Various physicochemical techniques were used to study the morphological, physical, and chemical characteristics of solid nanoadsorbents. The fabricated triple composite (HGC) showed a higher surface area (564.9 m²/g), acceptable pH_PZC (7.3), and average TEM particle size of 150 nm. These manufactured materials were used as solid adsorbents to eliminate cadmium ions from wastewater under various test conditions such as shaking time, sample dose, pH, starting Cd²⁺ concentration, and temperature. The data revealed that HGC had a greater adsorption capacity (246.10 mg/g) at 16 °C. The adsorption of Cd²⁺ was well applied by nonlinear pseudo-first order and Elovich as kinetic investigations, besides Langmuir and Temkin models according to adsorption isotherm investigations onto all the samples. Based on the values of reduced chi-square value (ꭓ²), the pseudo-first order and Langmuir models are more accepted models for Cd²⁺ adsorption. The thermodynamic study revealed that the adsorption process of Cd²⁺ is endothermic and spontaneous. After eight adsorption and desorption operations, the highest batch adsorption capacity was reduced by 1.45 % for NHAPs, 5.49 % for HC, and 5.24 % for HGC. Our findings demonstrated that HGC has outstanding adsorption capacity, quick kinetics, and high effectiveness promising composite in water treatment applications.