MODIFICAÇÃO QUÍMICA DO BAGAÇO DE CANA E CELULOSE USANDOANIDRIDO DO EDTA. USO DESTES MATERIAIS NA ADSORÇÃO DE METAISPESADOS EM SOLUÇÃO AQUOSA
The preparation of new materials that come from large sources and low costs as analternative for the effluents fitting including inorganic polluters to the levels demanded by thelegislation it?s the big technical-scientific interest. In this work it?s told the preparation of newmaterials, from cellulose and cane bagasse, to absorb ions Cu2+, Cd2+, Pb2+, Ca 2+ e Mg2+ inaqueous solution, therefore, decontaminate polluted water by those metals. The first part ofthe paper consisted in obtain the bagasse and the cellulose without treatment with sodiumhydroxide solution and the same treatments with NaOH solution. Nest, it was realized thechemical modification of all materials with EDTA dianhydride. The obtained materials werecharacterized by IR spectroscopy, elemental analyze, thermal analysis and x-rays diffraction.The second part of this work was constituted by the assessment of the ability of adsorption ofall modified materials related to Cu2+ ions in aqueous solution which concentration wasdetermined by atomic absorption. The cellulose and cane bagasse who suffered treatmentwith sodium hydroxide and later were modified with EDTA dianhydride showed a highercapacity of Cu2+ cations adsorption than the materials that weren?t treated with sodiumhydroxide and later modified. As a consequence the work went on evaluating the adsorptionability of the other metallic cations bagasse and cellulose that were treated with sodiumhydroxide e later modified with EDTA. The maximum capacity of adsorption for thesesmetallic cations stayed between 0,389 and 1,12mmol g-1 for the cellulose treated and modifiedwhile the bageasse treated and modified the maximum capacity of adsorption stayed between0,927 and 1,75mmol g-1. The adsorption of metallic cations by the modified materialsoccurred through chemical reactions of complexity. The competitive adsorption studiesshowed that the materials has bigger affinity by Cu2+ and this affinity reduce in the followingorder Pb2+>Cd2+>Ca2+?Mg2+ and is in agreement of the constant stability of the complexformed between the EDTA e those metals.
Advisor:Kátia Monteiro Novack; Laurent Frederic Gil; Rochel Monteiro Lago
School:Universidade Federal de Ouro Prêto
Source Type:Master's Thesis
Keywords:1 celulose teses 2 bagaço de cana 3 metais pesados 4 adsorção i universidade federal ouro preto ii título recursos hidricos
Date of Publication:03/22/2007