title: Immobilization of ethylenesulfide on babassu coconut epicarp and mesocarp for divalent cation sorption.
abstract: A new synthetic methodology route consisted in reacting the natural babassu coconut mesocarp (BCM) and babassu coconut epicarp (BCE) with ethylenesufide, for adding basic sulfur centers in pendant chains that possess high potential activity for coordinating divalent cations from aqueous solution. All biomaterials were characterized by elemental analysis, infrared (IR), (13)C NMR and thermogravimetry. The sulfur elemental analysis gave 2.00+/-0.05 and 8.67+/-0.01% for BCES and BCMS, which correspond to 0.60+/-0.01 and 2.71+/-0.01 mmol of this element per each gram of BCE and BCM, to confer a degree of functionalization of 20.2+/-0.07 and 86.7+/-0.01 mg g(-1). This synthesis enabled from IR weak SH band at 2544 cm(-1) due to the incorporation of the reagent into the structure. The basic centers favor copper sorption with increasing pH from 2 to 6 observed by a batchwise methodology and the data obtained from the chosen pH 6 were adjusted to Freundlich and Langmuir models, favoring fit for the latter equation. The kinetics of sorption was established at 30 min for both biopolymers with a pseudo-second-order model.
authors.affiliation: Departamento de Química/CCET, Universidade Federal do Maranhão, Av dos Portugueses S/N, Campus do Bacanga, 65080-540 São Luís, MA, Brazil.
authors.forename: Sirlane A A
authors.initials: SA
authors.lastname: Santana
authors.forename: Adriana P
authors.initials: AP
authors.lastname: Vieira
authors.forename: Edson C
authors.initials: EC
authors.lastname: da Silva Filho
authors.forename: Júlio C P
authors.initials: JC
authors.lastname: Melo
authors.forename: Claudio
authors.initials: C
authors.lastname: Airoldi
mesh_terms: D000327:Adsorption; D002413:Cations, Divalent; D003059:Cocos; D005030:Ethylenes / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D013055:Spectrophotometry, Infrared; D017550:Spectroscopy, Fourier Transform Infrared; D013440:Sulfides / Q000737:chemistry*
chemical_list: D002413:Cations, Divalent; D005030:Ethylenes; D013440:Sulfides; C036216:ethylene