Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2009-10-12
pubmed:abstractText
The chitosan microparticles were prepared using the inverse phase emulsion dispersion method and modified with thiourea (TCS). TCS was characterized by scanning electron microscope (SEM), the Fourier transform infrared (FT-IR) spectra, sulfur elemental analysis, specific surface area and pore diameter. The effects of various parameters, such as pH, contact time, initial concentration and temperature, on the adsorption of Pt(IV) and Pd(II) by TCS were investigated. The results showed that the maximum adsorption capacity was found at pH 2.0 for both Pt(IV) and Pd(II). TCS can selectively adsorb Pt(IV) and Pd(II) from binary mixtures with Cu(II), Pb(II), Cd(II), Zn(II), Ca(II), and Mg(II). The adsorption reaction followed the pseudo-second-order kinetics, indicating the main adsorption mechanism of chemical adsorption. The isotherm adsorption equilibrium was well described by Langmuir isotherms with the maximum adsorption capacity of 129.9 mg/g for Pt(IV) and 112.4 mg/g for Pd(II). The adsorption capacity of both Pt(IV) and Pd(II) decreased with temperature increasing. The negative values of enthalpy (DeltaH degrees ) and Gibbs free energy (DeltaG degrees ) indicate that the adsorption process is exothermic and spontaneous in nature. The adsorbent was stable without loss of the adsorption capacity up to at least 5 cycles and the desorption efficiencies were above 95% when 0.5 M EDTA-0.5M H2SO4 eluent was used. The results also showed that the preconcentration factor for Pt(IV) and Pd(II) was 196 and 172, respectively, and the recovery was found to be more than 97% for both precious metal ions.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
1873-3336
pubmed:author
pubmed:issnType
Electronic
pubmed:day
15
pubmed:volume
172
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
439-46
pubmed:meshHeading
pubmed:year
2009
pubmed:articleTitle
Adsorption of platinum(IV) and palladium(II) from aqueous solution by thiourea-modified chitosan microspheres.
pubmed:affiliation
Key Laboratory of Nuclear Resources and Environment (Ministry of Education), East China Institute of Technology, Xuefu Road No. 56, Fuzhou, Jiangxi 344000, PR China. minglzh@sohu.com
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't