<p><strong>Apstrakt je obrađen tehnologijama za optičko prepoznavanje teksta (OCR).</strong></p><p>Istraživana je mogućnost primene piljevine različitih vrsta drveta, tehničke celuloze i Kraft lignina kao adsorbenata različitih te&scaron;kih metala iz vode. Za adsorpciju te&scaron;kih metala koji su u vodi prisutni u vidu katjona, kao najbolji adsorbenti su se pokazale piljevine drveta hrasta i bagrema i Kraft lignin. Za adsorpciju hromatnih anjona najbolje su se pokazali Kraft lignin i piljevina drveta jele. Kapacitet adsorpcije piljevine drveta se može pobolj&scaron;ati prethodnim tretiranjem piljevine rastvorom natrijum hidroksida. Efikasnost adsorpcije te&scaron;kih metala iz vode je bolja: kada se primenjuju sitnije čestice piljevine, kada se radi sa većom količinom piljevine i/ili dvostepeno, na povi&scaron;enoj temperaturi. Utvrđen je optimalni pH za adsorpciju pojedinih te&scaron;kih metala, optimalno vreme kontakta adsorbenta i vode, uticaj prisustva različitih te&scaron;kih i lakih metala i anjona na efikasnost adsorpcije te&scaron;kih metala. Adsorbovani te&scaron;ki metali se mogu desorbovati sa piljevine drveta rastvorima različitih mineralnih kiselina. Piljevina drveta se može primeniti u vi&scaron;e ciklusa adsorpcije-desorpcije, uz ne&scaron;to smanjeni kapacitet adsorpcije. Ispitivani adsorbenti se mogu primeniti i u dinamičkim uslovima adsorpcije u koloni.</p> / <p><strong>Abstract was processed by technology for Optical character recognition (OCR).</strong></p><p>The possibility of adsorption of different heavy metals from water by sawdust of different species of wood, pulp, and Kraft lignin has been investigated. Oak and black locust sawdust, and Kraft lignin were shown to be the most efficient adsorbents for heavy metals in cationic form. Kraft lignin and fir sawdust were shown to be the most efficient adsorbents for chromium anions. Previous treatment of wood sawdust by sodium hydroxide solution can increase its adsorption capacity. Better adsorption efficiency was accomplished: when smaller parts of sawdust were used, when a large amount of sawdust was used and/or two stage process was applicated, and adsorption process was done on higher temperature. There were established: optimum initial pH value for different heavy metals, optimum adsorbent - water contact time, and degree of influence of other different heavy and lite metals, and anions on adsorption efficiency. Adsorbed heavy metals can be desorbed from vvood sawdust with solutions of different mineral acids. Sawdust can be applied in several cycles of adsorption - desorption, with some decrease of adsorption capacity. Investigated adsorbents can be also used in dynamic conditions of adsorption in column.</p>

Made available in DSpace on 2016-08-19T12:56:35Z (GMT). No. of bitstreams: 1 THAIS_ FRAZAO_ PINTO.pdf: 809423 bytes, checksum: b8458673c3339f802bd73fe54560bb20 (MD5) Previous issue date: 2010-08-02 / This work treated of modified wood sawdust with succinic anhydride and your application as adsorbent for remazol brilliant violet 5R (VR5) textile dye. The new material obtained was designated SMAS. The vibrations spectra indicated the presence of oxygenated groups, being the modification confirmed by Infrared, 13C NMR spectroscopy and titration of acid groups that indicated the introduction of carboxylic groups the material. It was found that the material can act as adsorbent to dye investigated and your active sites further enriched, due to considerably increased the adsorption capacity compared to natural material. Furthermore, the process of adsorption proved to be highly dependent of the pH and the largest amount adsorbed was obtained at pH 2.0. The adsorption of remazol brilliant violet 5R textile dye by wood sawdust modified with succinic anhydride followed the kinetic modeling of second order and was well described by the Freundlich model. In the conditions studied was reached a percentage of removal 51.66%. / Este trabalho tratou da modificação de serragem de madeira por anidrido succínico e sua aplicação como adsorvente para o corante têxtil violeta brilhante 5R remazol (VR5). O novo material obtido foi denominado SMAS. Os espectros vibracionais indicaram a presença de grupos oxigenados, sendo a modificação comprovada a partir de Infravermelho, RMN de 13C e da titulação dos grupos ácidos, que indicaram a inserção de grupos carboxílicos ao material. Verificou-se que o material pode atuar como adsorvente para o corante investigado e que houve um acréscimo no número de sítios ativos, pois aumentou consideravelmente a capacidade de adsorção frente ao corante, comparado ao material in natura. Além disso, o processo de adsorção se mostrou fortemente dependente do pH e a maior quantidade adsorvida foi obtida em pH 2,0. A adsorção do corante Violeta Remazol 5R por serragem de madeira quimicamente modificada com anidrido succínico seguiu a modelagem cinética de segunda ordem e foi bem descrita pelo modelo de Freundlich. Nas condições estudadas, alcançou-se uma porcentagem de remoção de 51,66 %.