Citation: Akbar, I.; Hanif, M.A.; Rashid, U.; Bhatti, I.A.; Khan, R.A.; Kazerooni, E.A. Green Nanocomposite for the Adsorption of Toxic Dyes Removal from Colored Waters. Coatings 2022, 12, 1955. https://doi.org/10.3390/ coatings12121955 Academic Editor: Maciej Fronczak Received: 10 November 2022 Accepted: 9 December 2022 Published: 13 December 2022 Publisher’s Note: MDPI stays neutral with regard to jurisdictional claims in published maps and institutional affil- iations. Copyright: © 2022 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https:// creativecommons.org/licenses/by/ 4.0/). coatings Article Green Nanocomposite for the Adsorption of Toxic Dyes Removal from Colored Waters Ishaa Akbar 1 , Muhammad Asif Hanif 1 , Umer Rashid 2, * , Ijaz Ahmad Bhatti 1 , Rais Ahmad Khan 3 and Elham Ahmed Kazerooni 4 1 Nano and Biomaterials Lab., Department of Chemistry, University of Agriculture, Faisalabad 38040, Pakistan 2 Institute of Nanoscience and Nanotechnology (ION2), Universiti Putra Malaysia, Serdang 43400, Selangor, Malaysia 3 Chemistry Department, College of Science, King Saud University, Riyadh 1145, Saudi Arabia 4 Department of Applied Biosciences, Kyungpook National University, Daegu 41566, Republic of Korea * Correspondence: umer.rashid@upm.edu.my or dr.umer.rashid@gmail.com; Tel.: +603-97697393 Abstract: The discharge of dyes from textile industries led to a broad range of toxicological and environmental effects, posing severe health issues for humans and animals worldwide. These dyes are highly stable and, if not adequately treated, remain in the environment for extended periods. Adsorption, the most efficient and cost-effective method, offers unique advantages for using natural adsorbents, such as marble waste composites, for dye removal. The easy availability of marble waste, its low cost, its eco-friendly nature, its ease of operation, its simplicity of design, its flexibility, and its great affinity for dyes make it a suitable option for dye removal. Golden marble waste nanocomposites are prepared for dye removal. The results from the studies suggested that treated golden marble composite materials exhibit better adsorption efficiency (224.8, 299.5, and 369.2 mg/g) for adsorptive removal of dyes than untreated golden marble composite materials (114.4 mg/g). This research also used isothermic and kinetic models to evaluate the effects of numerous parameters, for example, the initial dye concentration, pH, time, temperature, and adsorbent dose. The highest removal of 369.9 mg/g was achieved during the present study for blue dye at an optimized pH of 7 and a temperature of 30 ◦ C. It was observed that golden marble waste composites gave better R 2 (0.99) values for second-order kinetics in the kinetic model. Results obtained from comparing Langmuir, Freundlich, Temkin, Dubinin, and Herkin Jura isotherms showed that the R 2 values of the Langmuir isotherm for Foron red (0.97), the Temkin isotherm for Foron blue (0.98), and the Freundlich isotherm for Foron black dye (0.97) fit on adsorption for both treated and untreated composites. Characterization techniques, such as scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR), are also discussed for the structural determination of golden marble waste composites. Keywords: golden marble waste composites; Foron dyes; adsorption; SEM; FTIR 1. Introduction There has been a tremendous increase in wastewater production in the last few decades because of the growing pace of industrialization. It is one of the world’s most severe issues today, owing to various industries [1]. The release of harmful chemicals has caused severe health and environmental issues. Industrial wastewater contains a wide range of toxins, including dyes and pollutants of both organic and inorganic origins. Heavy metals, hydrocarbons, microbes, endocrine disruptors, and nutrients (nitrogen and phosphorus) are the primary contaminants in wastewater. These contaminants and organic matter make it suitable for the growth of pathogenic organisms, such as bacteria, viruses, and fungi. These organisms are responsible for various waterborne diseases [2]. Moreover, most of the dyes in this wastewater are carcinogenic and toxic [3]. Water pollution also negatively Coatings 2022, 12, 1955. https://doi.org/10.3390/coatings12121955 https://www.mdpi.com/journal/coatings