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nematollahzadeh--a
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Column study of Cr (VI) adsorption onto modified silica-polyacrylamide microspheres composite
, Article Chemical Engineering Journal ; Volume 210 , 2012 , Pages 280-288 ; 13858947 (ISSN) ; Shojaei, A ; Nematollahzadeh, A ; Abdekhodaie, M. J ; Sharif University of Technology
2012
Abstract
Adsorption of Cr (VI) from aqueous solution was studied using a continuous fixed bed column which is packed with a new micro-porous composite particle developed in this study. This composite particle is composed of silica porous particle in which acrylamide is polymerized within the pore regions of the silica particles. The composite particle was supposed to maintain the mechanical properties of polyacrylamide as efficient absorbent to serve appropriately in the continuous processes. In order to enhance the adsorption capacity of the composite particle, it was modified with ethylenediamine. Scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FT-IR) and...
Nano-scale modification of polysulfone membrane matrix and the surface for the separation of chromium ions from water
, Article Chemical Engineering Journal ; Volume 267 , May , 2015 , Pages 306-316 ; 13858947 (ISSN) ; Nematollahzadeh, A ; Mousavi, S. A ; Sharif University of Technology
Elsevier
2015
Abstract
In this study, aiming at hexavalent chromium removal from aqueous solutions, different strategies were proposed for developing hydrophilic and surface functional polysulfone (PSf) membrane. In addition to PSf membrane, three different types of membranes were prepared by addition of SiO2 nano-particles to the dope solution and/or by deposition of polydopamine (PDA) layer on the surface of the membranes. The membranes (i.e. PSf, PSf/PDA, PSf/SiO2 and PSf/SiO2/PDA) were characterized by different techniques. The membranes' transport properties and the separation performance were studied using a filtration unit operated at a continuous dead-end flow mode. The kinetics and the separation...
Amino functionalized hierarchically produced porous polyacrylamide microspheres for the removal of chromium(VI) from aqueous solution
, Article Journal of Porous Materials ; Volume 24, Issue 6 , 2017 , Pages 1705-1715 ; 13802224 (ISSN) ; Nematollahzadeh, A ; Shojaei, A ; Sharif University of Technology
Abstract
Porous silica microspheres were used as hard template to produce porous polyacrylamide microspheres. The microspheres were modified with ethylenediamine and used for the removal of hexavalent chromium [Cr(VI)] from aqueous solution. Scanning electron microscopy, thermogravimetry analysis, and Fourier transform infrared spectroscopy were utilized to characterize the adsorbent. Adsorption of Cr(VI) was conducted in batch and dynamic modes, and effect of various parameters including solution pH, adsorbent dose, initial concentration of Cr(VI) and agitation time on the adsorption process was studied. The optimum pH for the maximum adsorption (124 mg Cr(VI)/g dry polymer) was found to be 3....