Synthesis and characterisation of hybrids composed of calcined hydrotalcite and residual textile dyes

Abstract

There is growing concern about the health of our planet, which has led to a search for methods to purify and recover the pollutant materials that are released into the environment. Among all industries, the dyeing sector of the textile industry is considered one of the most polluting. However, advancements in technology, such as the use of nanoadsorbents, have made it possible to effectively treat and clean these wastewaters by harnessing the adsorption capabilities of these minerals. As a result, highly functional pigmentary hybrids with improved characteristics can be obtained. In this study, the research focuses on exploring the potential of hydrotalcite in combination with reactive, disperse, and direct dyes. Colour measurements are conducted using reflection spectrophotometers to evaluate the colour performance of the hybrid materials, yielding successful results. X-ray diffraction (XRD) analysis is used to verify the structural integrity of the hydrotalcite and confirm the adsorption of the dyes. Additionally, thermogravimetric tests (TGA) are carried out to assess the thermal stability of the different samples, while the colorants’ protection provided by the hydrotalcite is evaluated through total soluble recovery (TSR) measurements. An FTIR analysis is used to detect the presence of characteristic functional groups of the dyes in the resulting hybrids. Surface area and porosity measurements utilising the BET method, along with Scanning Electron Microscopy Energy+Dispersive X-ray spectroscopy (SEM–EDX) and X-ray photoelectron spectroscopy (XPS) tests, are also conducted. In summary, this study investigates the potential of hydrotalcite as an effective adsorbent for various dyes used in the textile industry. The research involves comprehensive analyses, including colour evaluation, structural characterisation, thermal stability assessment, and surface morphology examination. These findings contribute to the development of sustainable and environmentally friendly approaches in the treatment of textile wastewater.