AUTHOR=Nawaz Saleem , Salman Syed Muhammad , Ali Asad , Ali Basit , Shah Syed Nusrat , Rahman Latif Ur 

TITLE=Kinetics and thermodynamics investigations of efficient and eco-friendly removal of alizarin red S from water via acid-activated Dalbergia sissoo leaf powder and its magnetic iron oxide nanocomposite

JOURNAL=Frontiers in Chemistry

VOLUME=Volume 12 - 2024

YEAR=2024

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2024.1457265

DOI=10.3389/fchem.2024.1457265

ISSN=2296-2646

ABSTRACT=The present work aimed to highlight an efficient, readily accessible, and cost-effective adsorbent for removing the environmentally hazardous dye "Alizarin Red S" (ARS) from hydrous medium, derived from Dalbergia Sissoo leaves powder (DS), activated via sulfuric acid and composited with magnetic iron oxide nanoparticles (DSMNC). Both adsorbents are thoroughly characterized using techniques such as Fourier-transform infrared spectroscopy, point of zero charge, energydispersive X-ray spectroscopy and scanning electron microscopy showing that they have a porous structure rich in active sites. Different adsorption conditions are optimized with the maximum removal efficiency of 76.63% for DS and 97.89% for DSMNC. The study was highlighted via application of various adsorption isotherms including Freundlich, Langmuir, Temkin and Dubinin-Radushkevich to adsorption data. Pseudo-1st order, pseudo-2nd order, intra-particle diffusion models were utilized to investigate the kinetics and mechanism of adsorption. The Freundlich model and pseudo-2nd order kinetics exhibited the best fit, suggesting a combination of physical interactions, as confirmed by the D-R and Temkin models. The dominant adsorbateadsorbent interactive interactions responsible for ARS removal were implicit to be, hydrogen bonding, dispersion forces and noncovalent aromatic ring adsorbent pi-interactions.Thermodynamic parameters extracted from adsorption data provided distinct indication that removal of mutagenic dye "ARS" was exothermic and spontaneous on both DS and DSMNC, with DSMNC exhibiting higher removal efficiency.