title: Alternative use of cross-linked polyallylamine (known as Sevelamer pharmaceutical compound) as biosorbent.
abstract: In this study, an alternative use of Sevelamer carbonate (SEV, a cross-linked polyallylamine which is a widely known pharmaceutical compound) was suggested. The existence of primary and secondary amino groups (with different ratios) in its molecule increases its adsorption potential and use as biosorbent material. SEV was tested as biosorbent material aiming the removal of heavy metals and dyes from simulated effluents. As heavy metals and dyes, hexavalent chromium (Cr(VI)) and Remazol Brilliant Blue RN (RB) were used, respectively. A full adsorption study was done confirming the strong adsorption capability of SEV. The maximum theoretical adsorption capacity (Qm) was 772 and 485mg/g for single-component solutions of RB and Cr(VI), respectively; the respective values for binary mixtures of the same concentration (200mg/L) were 445 and 309mg/g respectively (calculated after fitting to Langmuir-Freundlich isotherm model at 25°C). The same experiments were also done at increasing temperatures (45 and 65°C) concluding thermodynamic remarks (ΔH(0)>0; ΔG(0)<0; ΔS(0)>0). The effect of contact time was analyzed running kinetic adsorption experiments and fitting them to pseudo-second order kinetic equation. The reusability was evaluated completing successfully 20 cycles of reuse (adsorption/desorption). The adsorption mechanism among SEV molecules and Cr(VI) or/and RB was clarified using FTIR spectroscopy before and after adsorption in line with a detailed theoretical modeling which provided important calculations. SEV was also characterized using swelling experiments, BET, SEM, XRD, TGA techniques.
authors.affiliation: Division of Chemical Technology, Department of Chemistry, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece.
authors.forename: George Z
authors.initials: GZ
authors.lastname: Kyzas
authors.affiliation: Division of Chemical Technology, Department of Chemistry, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece.
authors.forename: Panoraia I
authors.initials: PI
authors.lastname: Siafaka
authors.affiliation: Division of Chemical Technology, Department of Chemistry, Aristotle University of Thessaloniki, GR-541 24 Thessaloniki, Greece. Electronic address: dbic@chem.auth.gr.
authors.forename: Dimitrios N
authors.initials: DN
authors.lastname: Bikiaris
authors.affiliation: Molecular Engineering Laboratory, Department of Physics, University of Patras, GR-265 00 Patras, Greece; Institute of Chemical Engineering Sciences, Foundation of Research and Technology-Hellas (FORTH/ICE-HT), GR-265 04 Platani, Patras Acahaias, Greece.
authors.forename: Emmanuel N
authors.initials: EN
authors.lastname: Koukaras
authors.affiliation: Department of Chemistry, University of Crete, GR-714 09 Iraklion, Crete, Greece.
authors.forename: George E
authors.initials: GE
authors.lastname: Froudakis
mesh_terms: D000327:Adsorption; D002857:Chromium / Q000302:isolation & purification*; D004396:Coloring Agents / Q000302:isolation & purification*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D019216:Metals, Heavy / Q000302:isolation & purification*; D011073:Polyamines / Q000737:chemistry*; D000069603:Sevelamer / Q000737:chemistry*; D013696:Temperature; D013816:Thermodynamics; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*; D018508:Water Purification / Q000379:methods
chemical_list: D004396:Coloring Agents; D019216:Metals, Heavy; D011073:Polyamines; D014874:Water Pollutants, Chemical; D002857:Chromium; C074702:chromium hexavalent ion; C063994:polyallylamine; D000069603:Sevelamer
keywords: Adsorption; Azo dye; Hexavalent chromium; Modeling; Sevelamer