Removal of anionic dyes from aqueous solutions by an ion-exchanger based on pullulan microspheres

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• 作者：Marieta Constantin ; Ionela Asmar ; ei ; Valeria Harabagiu ; Luminita Ghimici ; Paolo Ascenzi ; Gheorghe Fundueanu
• 关键词：AO ; Acid Orange 7 ; APTAC ; (3-acrylamidopropyl)-trimethylammonium chloride ; AzB ; Azocarmine B ; CAB ; cellulose acetate butyrate ; CR ; Congo Red ; ECH ; epichlorohydrin ; ESEM ; environmental scanning electron microscopy ; KPS ; potassium peroxymonosulfate ; MO ; Met
• 刊名：Carbohydrate Polymers
• 出版年：2013
• 出版时间：2 January, 2013
• 年：2013
• 卷：91
• 期：1
• 页码：74-84
• 全文大小：945 K

文摘

Pullulan-graft-poly(3-acrylamidopropyl trimethylammonium chloride) (P-g-pAPTAC) microspheres were prepared by suspension cross-linking of the pullulan previously grafted with cationic moieties. Adsorption of Azocarmine B by the P-g-pAPTAC microspheres was used as a model to demonstrate the removal of anionic dyes from aqueous solutions. Batch adsorption studies concerning the effect of the contact time, pH, initial dye concentration, temperature, grafting, and the nature of sulfonated anionic dyes on the adsorption kinetics were investigated. Adsorption was shown to be independent of pH. The experimental data best fitted to the pseudo-second order model which provided values of the rate constant k₂ of 1.4 ¡Á 10^?4 g mg^?1 min^?1 for 100 mg L^?1 solution and of 3.7 ¡Á 10^?4 g mg^?1 min^?1 for 500 mg L^?1 solution. From the Langmuir isotherm linear equation, the maximum adsorption capacity determined was 113.63 mg of Azocarmine B per gram of adsorbent; the negative value of the free energy change indicated the spontaneous nature of the adsorption process.