A novel structure for removal of pollutants from wastewater Nabila S. Ammar a , Hanan Elhaes b , Hanan S. Ibrahim a , Walid El hotaby c , Medhat A. Ibrahim c,⇑ a Water Pollution Research Department, National Research Centre, 12311 Dokki, Cairo, Egyptb Physics Department, Faculty of Women for Arts, Science, and Education, Ain Shams University, 11757 Cairo, Egyptc Spectroscopy Department, National Research Center, 12311 Dokki, Cairo, Egypth i g h l i g h t s Quantum mechanical model for aquatic plant. A microsphere from natural resources. Removal and recovery of Pb(II). g r a p h i c a l a b s t r a c t a r t i c l e i n f o Article history: Received 16 July 2013 Received in revised form 10 October 2013 Accepted 17 October 2013 Available online 26 October 2013 Keywords: Lead Microspheres Chitosan PM5 Kinetic models Isotherm models a b s t r a c t Dried water hyacinth was subjected to molecular modifications using quantum mechanical calculations. The model simulates the modified plant as 3 cellulose units, one lignin and some metal oxides namely CaO; FeO and Al(OH) 3 are attached through O-Linkage. The model suggests the ability to remove inor- ganic pollutants from wastewater according to unique hydrogen bonding and high total dipole moment. Based on thi s mo del micro sph ere s are syn thesized in the lab ora tor y fro m dri ed wa ter hyacinth andchito - san follo wing self-ass emb ly meth od. FTIR spec trum of micr osphe res exhi bits only the chara cter istic band s for raw mate rial s which give st rong evidence that the formed material is a comp osite . The anal ysis of SEM micr ogra phe s of microsph eres showed that the fiber s of water hyac inth are imbedde d in the crosslinked chitosan matrix. Batch adsorption kinetic models revealed that the sorption of lead ions on microsphere was very fast and the equilibrium was rapidly attained within 30 min. and properly corre- lated with the second-order kinetic model. Different models of isotherm sorption were used to describe the Pb (II) adsorption onto microspheres. From Langmuir isotherm, the maximum adsorption capacity (q max ) for Pb(II ) was 312.5 mg/g , which is about 3 time s higher than that of the crude hyacint h. The free energy (E) was 15.798 kJ/mol which shows that the sorption process is endothe rmic and the mechanism of reaction is an ion-exchange. Even after four cycles of adsorption–desorption, the adsorption capacity was maintained and the decline in efficiency was less than 10%. 2013 Elsevier B.V. All rights reserved. Introduction Pb(II) is being intensively released into the environment as a res ult of sev er al ind ust ria l act ivi tie s, suc h as me tal pla ting, microelectronics, battery manufacture, tanneries, oil refining, and mining. It spreads into the environment through soils and water streams and accumulates along the food chain, resulting in a high risk to human health[1,2]. As it does not degrade biologically, the control of Pb(II) pollution has special importance for both organ- ism s that liv e in wa ter and tho se tha t benefit from wa ter [3] . Henc e, the dev elop ment of effi cient techniqu es for the removal 1386-1425/$ - see front matter2013 Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.saa.2013.10.063 ⇑ Corresponding author. Tel.: +20 12 2727636; fax: +20 23 3370931. E-mail address: medahmed6@ yahoo.com(M.A. Ibrahim). Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy 121 (2014) 216–223 Contents lists available at ScienceDirect Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy journal homepage: www.elsevier.com/locate/saa