Torres Jocilene D, Faria Elaine A, Prado Alexandre G S
Instituto de Química, Universidade de Brasília, Caixa Postal 4478, 70904-970 Brasília, Distrito Federal, Brazil.
J Hazard Mater. 2006 Feb 28;129(1-3):239-43. doi: 10.1016/j.jhazmat.2005.08.034. Epub 2005 Oct 10.
The chelate molecule, ethylenediamine, has been incorporated onto the surface of cellulose by sequential reaction of cellulose fibres with phosphorous oxychloride followed by the chelating agent. The modified material (CelNN) retained its fibrous nature and was shown to be efficient at adsorbing divalent metal cations from water by complexation. Adsorption isotherms were determined for suspensions of CelNN in metal ion solutions of different concentrations, and the data were adjusted to fit the modified Langmuir equation. The maximum numbers of moles of Cu2+, Ni2+ and Zn2+ adsorbed per gram of modified cellulose were 1.64 x 10(-3), 5.25 x 10(-4) and 1.06 x 10(-3), respectively. The thermodynamic effects related to the adsorption of metal ion onto the cellulose surface were determined by calorimetric titration. Gibbs free energy was spontaneous for all interactions. The adsorption processes all exhibited endothermic enthalpy values and were accompanied by increases in entropy.
螯合分子乙二胺已通过纤维素纤维与三氯氧磷随后与螯合剂的顺序反应被结合到纤维素表面。改性材料（CelNN）保留了其纤维性质，并通过络合作用被证明能有效地从水中吸附二价金属阳离子。测定了不同浓度金属离子溶液中CelNN悬浮液的吸附等温线，并对数据进行调整以拟合修正的朗缪尔方程。每克改性纤维素吸附的Cu2+、Ni2+和Zn2+的最大摩尔数分别为1.64×10(-3)、5.25×10(-4)和1.06×10(-3)。通过量热滴定法测定了与金属离子吸附到纤维素表面相关的热力学效应。所有相互作用的吉布斯自由能都是自发的。吸附过程均表现出吸热的焓值，并伴随着熵的增加。
