Preparation and characterization of zeolite from waste Linz-Donawitz (LD) process slag of steel industry for removal of Fe3+ from drinking water

Cubical-shaped zeolite A was synthesized from the Linz-Donawitz (LD) process slag of the Steel Industry, utilizing conventional fusion-assisted hydrothermal treatment. Morphological and Physico-chemical characterizations were performed by various characterization techniques. A weight ratio of 1:1.2 (LD-slag: NaOH) was maintained during fusion, which provides a better binding effect with better mechanical stability to the zeolite framework. Fe3+ adsorption studies were performed at 273, 298, 303, and 308 K, respectively, within the range of 10-40 mg L (1) Fe3+ ion concentration for kinetic and isotherm studies. A maximum adsorption capacity of 27.55 mg g (1) was obtained at a 1.4 g L (1) adsorbent dosage, with 99.99% Fe3+ ion removal. Moreover, the Fe3+ adsorption study obeyed the pseudo-second-order kinetic model, whereas multistage diffusion controlled the adsorption process. Langmuir isotherm model best fitted the equilibrium data suggesting the highly negative charge over the adsorbent surface played a vital role in the electrostatic attraction of Fe3+ ions. Isomorphic replacement of silicon by aluminum ion imparted a highly negative charge over the zeolite surface in the primary structure unit. For real-life sample drinking water, the Fe3+ ion removal efficiency increases to 97.7%. (C) 2021 The Society of Powder Technology Japan. Published by Elsevier B.V. and The Society of Powder Technology Japan. All rights reserved.