title: Selective lanthanide sorption and mechanism using novel hybrid Lewis base (N-methyl-N-phenyl-1,10-phenanthroline-2-carboxamide) ligand modified adsorbent.
abstract: This study aims to develop a highly selective Lewis base adsorbent to investigate the selective sorption and recovery of Eu(III) and Sm(III) from wastewater. The oxygen and nitrogen donor atoms containing Lewis base N-methyl-N-phenyl-1,10-phenanthroline-2-carboxamide (MePhPTA) ligand was synthesized and subsequently an adsorbent was prepared by direct immobilization onto mesoporous silica. Determined maximum adsorption capacities were 125.63 and 124.38 mg/g for Eu(III) and Sm(III), respectively. Experiments with mixed-cations solutions showed that the sequence of preferential adsorption was Eu(III)>Sm(III). The lanthanide sorption by hybrid Lewis base adsorbent (HyLBA) was not adversely affected by the presence of sodium, potassium, calcium, magnesium, chloride, sulfate and nitrate ions due to strong affinity between hard Lewis acid lanthanide and hard Lewis base adsorbent. The crystallography for the Sm-MePhPTA complex suggested that MePhPTA was strongly coordinated to Sm(III) with oxygen and nitrogen by forming a stable complex with two 5-membered rings. The data clarified that bond lengths between Sm(III) and amide oxygen (2.475Å) were shorter than SmN (2.662Å) in phenanthroline moiety indicating strong oxygen driven HyLBA. The results suggested that HyLBA has a good prospect of promising applications for separation/sorption of lanthanide ions from effluents.
authors.affiliation: Actinide Coordination Chemistry Group, Quantum Beam Science Directorate, Japan Atomic Energy Agency, SPring-8, Hyogo 679-5148, Japan. awual75@yahoo.com
authors.forename: Md Rabiul
authors.initials: MR
authors.lastname: Awual
authors.forename: Tohru
authors.initials: T
authors.lastname: Kobayashi
authors.forename: Yuji
authors.initials: Y
authors.lastname: Miyazaki
authors.forename: Ryuhei
authors.initials: R
authors.lastname: Motokawa
authors.forename: Hideaki
authors.initials: H
authors.lastname: Shiwaku
authors.forename: Shinichi
authors.initials: S
authors.lastname: Suzuki
authors.forename: Yoshihiro
authors.initials: Y
authors.lastname: Okamoto
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Yaita
mesh_terms: D000327:Adsorption; D018360:Crystallography, X-Ray; D005063:Europium / Q000737:chemistry*; D058115:Lewis Bases / Q000737:chemistry*; D008024:Ligands; D010618:Phenanthrolines / Q000737:chemistry*; D012493:Samarium / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods; D014874:Water Pollutants, Chemical / Q000737:chemistry*
chemical_list: D058115:Lewis Bases; D008024:Ligands; D010618:Phenanthrolines; D014874:Water Pollutants, Chemical; D012493:Samarium; D005063:Europium; D012822:Silicon Dioxide