title: Adsorption and desorption of Sr(II) ions in the gels based on polysaccharide derivates.
abstract: Adsorption behavior of Sr(II) ions was investigated using gel adsorbents based on three types of polysaccharide derivates: carboxymethylated cellulose (CMC), carboxymethylated chitosan (CMCts) and hydroxypropyl methylcellulose phthalate (HPMCP). Maximum adsorption capacities were reached in about 0.5h for CMCts, 1h for CMC, and 2h for HPMCP. The adsorption capacity increased with increasing pH, and decreasing ionic strength. The maximum adsorption capacity of Sr(II) ions into CMC, CMCts and HPMCP gels at 25 degrees C were 108.7, 99.0, and 83.3mg/g gel, respectively, based on the Langmuir isotherms. XPS analysis indicates that Sr(II) ions are adsorbed into the three adsorbents according to the ion-exchange mechanism. Desorption of Sr(II) ions could be carried on by immersing the adsorbents in the solutions with low pH or high ionic strength, or heating the adsorbents in the moist hot environment.
authors.affiliation: Department of Applied Chemistry, Beijing National Laboratory for Molecular Sciences, College of Chemistry and Molecular Engineering, Peking University, 100871 Beijing, PR China.
authors.forename: Min
authors.initials: M
authors.lastname: Wang
authors.forename: Ling
authors.initials: L
authors.lastname: Xu
authors.forename: Jing
authors.initials: J
authors.lastname: Peng
authors.forename: Maolin
authors.initials: M
authors.lastname: Zhai
authors.forename: Jiuqiang
authors.initials: J
authors.lastname: Li
authors.forename: Genshuan
authors.initials: G
authors.lastname: Wei
mesh_terms: D000327:Adsorption; D002266:Carboxymethylcellulose Sodium / Q000737:chemistry; D048271:Chitosan / Q000031:analogs & derivatives / Q000737:chemistry; D002852:Chromatography, Ion Exchange / Q000379:methods; D005782:Gels; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D007477:Ions; D008747:Methylcellulose / Q000031:analogs & derivatives / Q000737:chemistry; D011134:Polysaccharides / Q000737:chemistry*; D013324:Strontium / Q000737:chemistry*; D013696:Temperature; D013997:Time Factors; D014874:Water Pollutants, Chemical / Q000302:isolation & purification; D018508:Water Purification / Q000379:methods
chemical_list: D005782:Gels; D007477:Ions; D011134:Polysaccharides; D014874:Water Pollutants, Chemical; C514968:carboxymethyl-chitosan; D008747:Methylcellulose; D048271:Chitosan; C053309:hydroxypropyl methylcellulose phthalate; D002266:Carboxymethylcellulose Sodium; D013324:Strontium