论文部分内容阅读
An ion exchanger was prepared by sulfonation of cork-waste chars. The exchange properties of the resultant materialwere characterized using Na+, Ca2+ or Fe3+ aqueous solutions, The content of metal ions in the solutions weredetermined by atomic absorption spectrometry. On the basis of the results obtained, the chemical equilibrium andits thermodynamic aspects related to the ion exchange process were studied. It was found that equilibrium constantK varies by the order: Na+＜Ca2+＜Fe3+, its value increasing with increasing temperature, and that △H°＞0 and△S°＞0, with -△G° following the sequence: Ca2+＞Na+＞Fe3+,