A Novel Scaffold Based on Biopolymers and Gallium-Containing Hydroxyapatite as Green Technology

Abstract

Waste generated by the textile industry is one of the primary pollutants in aquatic environments. It is estimated that about 10 to 15% of the dyes used do not chemically interact with the fabric fibers, with a loss of this pollutant in the wastewater. One of the alternatives for pollutant removal is the adsorption process, which is viable compared to other separation methods. There is a range of materials that are used in adsorption processes. Among them, polysaccharides have numerous advantages regarding their use: they are non-toxic, abundant in nature, biodegradable, hydrophilic, and have several other properties. The study aimed to investigate a novel scaffold based on biopolymers and gallium-doped hydroxyapatite for dyes removal in an aqueous solution. The scaffold was characterized by X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), thermogravimetric analysis (TGA), scanning electron microscopy, and energy dispersive X-ray spectroscopy (SEM-EDS), swelling and adsorption tests. From the XRD, the gallium presence did not change the crystal structure of hydroxyapatite. The FTIR and TG spectra of the scaffold indicate that there were interactions between the precursor materials in the production of the same by shifting the characteristic bands and increasing thermal stability. SEM showed essential characteristics for the application of scaffolds in the adsorptive process through the presence of pores on the upper side and the inner surface of the scaffold. Open and interconnected pores with average diameters in the range of 60 mm on the upper and lateral face surface and 40 mm on the inside of the scaffold were observed. A more significant number of pores were observed inside, thus influencing the adsorption. In addition, EDS was possible to qualitatively prove the presence of precursor elements for the formation of the scaffold. It is concluded that the scaffolding was successful and showed excellent potential for removing Remazol Blue RGB and Remazol Red with adsorption of 341.41 ± 6.82 and 584.89 ± 23.39 mg/g, respectively.