ARTICLE IN PRESS JID: JTICE [m5G;March 22, 2018;5:50] Journal of the Taiwan Institute of Chemical Engineers 000 (2018) 1–10 Contents lists available at ScienceDirect Journal of the Taiwan Institute of Chemical Engineers journal homepage: www.elsevier.com/locate/jtice High-stability polyamine/amide-functionalized magnetic nanoparticles for enhanced extraction of uranium from aqueous solutions Mohammad Al-Harahsheh a,∗ , Mohannad AlJarrah a , Mohannad Mayyas b , Muna Alrebaki a a Chemical Engineering Department, Jordan University of Science and Technology, Irbid 22110, Jordan b University of New South Wales, School of Materials Science and Engineering, Sydney 2052, Australia a r t i c l e i n f o Article history: Received 26 November 2017 Revised 24 February 2018 Accepted 1 March 2018 Available online xxx Keywords: Magnetic nanoparticles Carbon coating Polyethyleneimine Adsorption Uranium a b s t r a c t In this work, carbon-coated magnetic iron oxide nanoparticles (CCM) functionalized with polyethyleneimine/amide (PEIA) were successfully prepared. The prepared nanocomposite (CCMNPs-PEIA) was characterized by XRD, TEM, FT–IR, TGA and VSM techniques. The stability of CCM was tested in both acidic and basic media and they showed a high stability with good magnetic properties. CCMNPs-PEIA were used for separation of U (VI) from aqueous solutions. Several process parameters were tested to investigate the removal efficiency, adsorption capacity and reusability of the CCMNPs-PEIA including, pH, initial concentration of uranium, and desorption and activation media. The CCMNPs-PEIA nanocomposite was found to have excellent affinity toward U over a wide pH range. Surface oxidation of CCM was found to be of major effect of the adsorption capacity of CCMNPs-PEIA due it carboxylation which enhanced PEIA attachment to the carbon surface. The experimental uptake of the prepared nanocomposite was found to be 127.5 mg (U/g (nanocomposite), while the one calculated according to Langmuir model was found to be 123.45 mg/g with a correlation coefficient (R 2 ) of 0.991. The kinetics analysis of the adsorption process suggests that the kinetics can be described well by the pseudo-second order model suggesting that the rate limiting step is chemisorption. © 2018 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved. 1. Introduction Adsorption techniques have been found to be superior for wa- ter treatment due to their simplicity of design, selectivity, low cost, flexibility, ease of operation, efficient technology, and wider appli- cability for the removal various types of pollutants. Natural adsorbents, under ambient conditions, exhibit either low adsorption capacity or weak affinity for sorbate. The use of chemical modification to produce nanocomposite material increase their adsorption capacity and selectivity toward heavy metal ions, which have functional groups such as amine, amide, carbonyl, ami- doxime, chitosan etc. Adsorbents with nanoscale have better efficiency in removing contaminants from wastewater, due to their high surface to volume ratio and better dispersion in aqueous solutions. Further research is needed to improve firstly stability, capacity, selectivity, and ki- netics rate, secondly, the adsorbent reusability for multicycle use, and finally, the ease of separating NP from water after desorption process. ∗ Corresponding author. E-mail address: msalharahsheh@just.edu.jo (M. Al-Harahsheh). Numerous sources release U(VI) into the environment such as nuclear power industries, fertilizers mine tailings, natural deposits and other processing of uranium application [1]. It is also the most predominant fuel in nuclear reactors and can pose serious risk to the environment during mining operations and treatment of spent nuclear fuel [2]. On the other hand, due the expected shortage of its resources, great attention was paid to uranium recovery from secondary resources, including sea water, ground water, wastewa- ter and other sources. Therefore, significant research work is being carried out to develop highly effective extraction methods for ura- nium from the point view of environmental protection, resource conservation and energy security [3]. Several approaches are be- ing considered for uranium removal from water streams including membrane separation [4], ion exchange [5], solvent extraction and adsorption techniques [6]. Magnetic nanoparticles (MNPs) have received great attention of researchers in recent years due to their magnetic properties and the possibility to manipulate selective functionalization on their surface [7]. Therefore, they have found applications including, but not limited to, medicine [8] and biomedical engineering, infor- mation storage, biosensing applications, and water treatment [9], green energy storage [10]. https://doi.org/10.1016/j.jtice.2018.03.005 1876-1070/© 2018 Taiwan Institute of Chemical Engineers. Published by Elsevier B.V. All rights reserved. Please cite this article as: M. Al-Harahsheh et al., High-stability polyamine/amide-functionalized magnetic nanoparticles for enhanced extraction of uranium from aqueous solutions, Journal of the Taiwan Institute of Chemical Engineers (2018), https://doi.org/10.1016/j.jtice.2018.03.005