Removal of Heavy Metal Ions from Wastewater Using Hydroxyethyl Methacrylate-Modified Cellulose Nanofibers: Kinetic, Equilibrium, and Thermodynamic Analysis.

Mohamed Gouda,Abdullah Aljaafari

doi:10.3390/ijerph18126581

Abstract

The objective of this work was to fabricate modified cellulose nanofibers (CNFs) for the removal of heavy metal ions (Cd2+ and Pb2+) from wastewater. Cellulose was modified with 2-hydroxyethyl methacrylate (HEMA) via grafting copolymerization using the microwave-assisted technique in the presence of ceric ammonium nitrate (CAN) as an initiator. Prepared cellulose-graft-(2-hydroxyethyl methacrylate) (HEMA/C) copolymers were characterized using Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Different factors affecting the graft yield, such as irradiation time, monomer concentrations, and initiator concentrations, were investigated. Furthermore, cellulose-graft-(2-hydroxyethyl methacrylate) copolymer nanofibers (HEMA/CNF) were fabricated by electrospinning using N,N-dimethylacetamide-LiCl as a solvent. Electrospun nanofiber copolymers were characterized using SEM and thermogravimetric analysis (TGA). Operating parameters, including time, starting metal concentrations, and adsorbent concentration, were analyzed at a pH of 5.6 for the two metal ions. The best-fit model of adsorption energy was the pseudo-second-order model, and adsorption isotherms at equilibrium were well described by the Langmuir and Freundlich models. The negative values of ΔG and positive values of ΔH and ΔS suggest that the adsorption of Cd2+ and Pb2+ ions onto electrospun HEMA/CNF is a spontaneous, endothermic, and favorable reaction.

Highlights

IntroductionFreshwater requirements continue to rise worldwide as a result of population growth, urbanization, food and energy security demands, global economic processes such as international trade, changing diets, expanding agribusiness, and atmosphere changes [1]
Freshwater requirements continue to rise worldwide as a result of population growth, urbanization, food and energy security demands, global economic processes such as international trade, changing diets, expanding agribusiness, and atmosphere changes [1].Global water demand is anticipated to increase by 55% from 2015 to 2050, primarily because of increasing industry and household use [1]
Cellulose with a molecular weight of 30,000, 2-hydroxyethyl methacrylate (HEMA), ceric ammonium nitrate (CAN) as an initiator, N,N-dimethylacetamide, and lithium chloride were purchased from Sigma-Aldrich, St

Summary

Introduction

Freshwater requirements continue to rise worldwide as a result of population growth, urbanization, food and energy security demands, global economic processes such as international trade, changing diets, expanding agribusiness, and atmosphere changes [1]. Global water demand is anticipated to increase by 55% from 2015 to 2050, primarily because of increasing industry and household use [1]. Water contamination has become a crucial issue throughout the world. A wide range of wastewater sources, such as household and industrial effluents, sewage, stormwater, leachate, and septic tank wastewater, are viewed as wastewaters by society [2]. Industrial wastewater is a significant source of contamination in water bodies. Industrial wastewater contaminants can be divided into two groups: inorganic and organic compounds [3]

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