Preparation and characterization of novel mesoporous chitin blended MoO 3 -montmorillonite nanocomposite for Cu(II) and Pb (II) immobilization Hany Fathy Heiba a, ⁎, Asia A. Taha b , Alaa R. Mostafa c , Laila A. Mohamed a , Mamdouh A. Fahmy a a Marine Chemistry Department, Environmental Division, National Institute of Oceanography and Fisheries (NIOF), Alexandria, Egypt b Department of Chemistry, Faculty of Science, Alexandria University, Alexandria, Egypt c Department of Environmental Sciences, Faculty of Science, Alexandria University, Alexandria, Egypt abstract article info Article history: Received 4 November 2019 Received in revised form 15 February 2020 Accepted 22 February 2020 Available online 24 February 2020 Keywords: Chitin-MoO 3 -MMT nanocomposite Adsorption surface mapping Metal adsorption Isotherm Kinetics Thermodynamics ANOVA statistical analysis A novel mesoporous chitin blended MoO 3 -Montmorillonite nanocomposite was prepared through three-steps synthesis. First, chitin was extracted from prawn shell then MoO 3 -MMT was prepared, and lastly, chitin was blended with MoO 3 -MMT. Chitin-MoO 3 -MMT was applied for the removal of Cu(II) and Pb(II) from wastewater. XRD characterization revealed MoO 3 solubility in MMT interlayers, SEM showed a nanocomposite formation with sharp nanorods like-structure and length ranging from 60 to 77.7 nm. FTIR exhibited fundamental changes in the surface functional groups after adsorption. XPS analysis before and after adsorption showed the domina- tion of chemical bonding with N and O. N 2 adsorption-desorption isotherm displayed H 3 -type hysteresis loop and a pore size diameter of 10.67 nm confirming the mesoporous nature. Adsorption efficiency was studied as a function of pH, time, metal concentration and adsorbent mass. Adsorption capacity (Q e ) values were 19.03 and 15.92 mg.g -1 for Cu(II) and Pb(II) respectively. The metal surface coverage mapping was 1.87 × 10^ 19 and 4.34 × 10^ 18 atoms/m 2 for Cu(II) and Pb(II) respectively. Adsorption followed Langmuir isotherm and pseudo- second-order (PSO) kinetics suggesting a monolayer chemisorption domination. Intraparticle diffusion (IPD) model showed a boundary layer control. Thermodynamically, the adsorption was spontaneous and endothermic with activation energies 25.94 and 29.37 kJ.mol -1 for Cu(II) and Pb(II) respectively. © 2020 Published by Elsevier B.V. 1. Introduction The rapid increase in human population has resulted in a parallel rise in the demand for clean water around the world, however the vast growth of industrial activities has dramatically reduced the quality and quantity of the safe water [1]. Therefore, water pollution has be- come the biggest environmental problem that threatens the living being [2]. Heavy metals are considered very hazardous water contami- nants due to their toxicity, mobility, non-biodegradable nature and bio- accumulation. Essential heavy metals play a vital role in biological functions, but they cause severe harms if they exceed the tolerance levels [2]. Water pollution with metals is mainly due to the direct or in- direct discharge of industrial and agricultural wastewater streams laden with heavy metals. In addition to the industrial sources, lead and copper specifically can easily reach drinking water due to corrosion of plumbing materials such as water pipes. Exposure to lead and copper ions even at low concentrations can cause various diseases and disor- ders to humans [3]. Lead Pb(II) causes liver and kidney dysfunction, cen- tral nervous system disorders, anemia, infertility. Copper Cu(II) causes lung cancer, digestion problems, liver malfunction and kidney impair- ment [4]. Thus, the removal of Pb(II) and Cu(II) from polluted water be- fore being discharged is a necessity. Among various water treatment techniques, adsorption is considered to be the most convenient method [5]. Application of nanotechnology in water treatment has potential ad- vantages such as high chemical activity and adsorption capacity [6]. The organic-inorganic nanocomposite is one of the most promising mate- rials for adsorption prospective, because it exhibits the advantages of both organic and inorganic materials. In this study, chitin was extracted from prawn shell and utilized in the synthesis of mesoporous chitin blended MoO 3 -MMT nanocompos- ite, then the nanocomposite was applied in the remediation of Pb(II) and Cu(II). The surface texture of the nanocomposite was examined using BET analysis, XPS, FTIR, SEM, XRD and zeta sizer. XPS analysis was used to examine the immobilization mechanism through tracking the main surface elements affected by the adsorption process.The International Journal of Biological Macromolecules 152 (2020) 554–566 ⁎ Corresponding author at: Marine Chemistry Department, Environmental Division, National Institute of Oceanography and Fisheries (NIOF), PO Box: 21556, Qayetbey, Alanfoushy, Alexandria, Egypt. E-mail addresses: hanyheiba@gmail.com, hf.heiba@niof.sci.eg (H.F. Heiba). https://doi.org/10.1016/j.ijbiomac.2020.02.254 0141-8130/© 2020 Published by Elsevier B.V. Contents lists available at ScienceDirect International Journal of Biological Macromolecules journal homepage: http://www.elsevier.com/locate/ijbiomac