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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Aplica??o da perlita expandida modificada com ortofenantrolina na remo??o do negro de eriocromo T em ?guas residuais geradas em laborat?rios de ensino de qu?mica

Almeida, Janiele Mayara Ferreira de 01 July 2015 (has links)
Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-04-25T20:37:14Z No. of bitstreams: 1 JanieleMayaraFerreiraDeAlmeida_DISSERT.pdf: 3359856 bytes, checksum: 7087c90fbed8ed7de14a5527260574ce (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-04-26T23:21:56Z (GMT) No. of bitstreams: 1 JanieleMayaraFerreiraDeAlmeida_DISSERT.pdf: 3359856 bytes, checksum: 7087c90fbed8ed7de14a5527260574ce (MD5) / Made available in DSpace on 2016-04-26T23:21:56Z (GMT). No. of bitstreams: 1 JanieleMayaraFerreiraDeAlmeida_DISSERT.pdf: 3359856 bytes, checksum: 7087c90fbed8ed7de14a5527260574ce (MD5) Previous issue date: 2015-07-01 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq) / No presente trabalho realizou-se o estudo da remo??o do negro de eriocromo T usando a perlita expandida modificada com ortofenantrolina, atrav?s da t?cnica de adsor??o. O estudo do processo de adsor??o foi realizado atrav?s da averigua??o do efeito da concentra??o inicial do corante, tempo de contato e varia??o de pH da solu??o (meio ?cido e alcalino) no processo de adsor??o, para um efluente denominado sint?tico (solu??o aquosa do negro de eriocromo T) e um efluente real (gerado a partir do ensaio de determina??o da dureza da ?gua, por titulometria de complexa??o). Os materiais foram caracterizados por Termogravimetria/An?lise T?rmica Diferencial (TG/DTA), Espectroscopia de absor??o na regi?o do infravermelho (IV), Difra??o de raios X (DRX) e Microscopia eletr?nica de varredura (MEV). Pelas an?lises de DRX observaram-se reflex?es referentes ? ortofenantrolina na perlita expandida modificada. E por an?lise de IV observou-se um aumento na intensidade e um minucioso alargamento da banda de absor??o referente ? deforma??o axial da liga??o O-H dos grupos silan?is da perlita (Si-OH). No estudo do tempo de equil?brio, na faixa de tempo avaliada (5 a 230 min) n?o foi poss?vel observar a exist?ncia de um tempo de equil?brio, provavelmente atribu?da ao tipo de intera??o entre o negro de eriocromo T e a perlita expandida modificada com ortofenantrolina, sendo uma intera??o de origem superficial. No estudo de efeito da concentra??o inicial do adsorbato, no caso 2,0x10-4 mol/L em pH natural (pH 5), obteve-se o maior valor de porcentagem de remo??o da cor do negro de eriocromo T, com 63,74 % de remo??o em 20 minutos de contato. Na avalia??o do efeito da varia??o do pH da solu??o de negro de eriocromo T no processo de adsor??o, concluiu-se que quanto mais ?cido o meio, maior a porcentagem de remo??o do corante, sendo resultado de uma intera??o ?cido-base entre o adsorbato e o adsorvente. No estudo da remo??o do negro de eriocromo T no efluente real empregou-se as condi??es otimizadas atrav?s do estudo com efluente sint?tico. A remo??o do corante em pH 10, ou seja, pH natural do efluente n?o foi significante alcan?ando-se o valor m?ximo de porcentagem de remo??o da cor de 8,12 %, j? em pH 3 obteve-se remo??o de cor m?xima de 100,00 % da cor, mais uma vez indicando que o negro de eriocromo T interage melhor e eficazmente com o adsorvente em valores de pH ?cido (pH 5 ou 3), e mais eficientemente em pH 3. Sendo assim pode-se citar que a perlita expandida (um aluminossilicato amorfo, naturalmente ?cido) modificada com ortofenantrolina (uma base de Bronsted), consiste em um material ex?mio e eficaz na remo??o de corantes do tipo ?cido de solu??es aquosas, nas condi??es expressas neste estudo, podendo ser aplicada como adsorvente deste corante tamb?m em um efluente real. / In this study, we carried out the study of Eriochrome black T removal using expanded perlite modified orthophenanthroline by adsorption technique. The study of the adsorption process was performed by investigating the effect of the initial dye concentration, contact time and pH range of the solution (acidic and alkaline) in the adsorption process, for a so-called synthetic effluent (aqueous solution of black eriochrome T) and a real effluent (generated from the test for determining the water hardness, by complexation titration). The materials were characterized by Thermogravimetry / Differential Thermal Analysis (TG / DTA), absorption spectroscopy in the infrared (IR), X-ray Diffraction (XRD) and scanning electron microscopy (SEM). By analysis of XRD observed thinking on orthophenanthroline the modified expanded perlite. And by IR analysis showed an increase in intensity and a detailed enlargement of the absorption band related to the axial deformation of the OH bond of silanol groups of perlite (Si-OH). In the equilibration time of the study, in the evaluated time range (5-230 min) was not possible to observe the existence of a balance of time, probably attributed to the type of interaction between the Eriochrome black-T and the expanded perlite modified orthophenanthroline, being an interaction of surface origin. In the study effect of the initial concentration of the adsorbate in the case 2,0x10-4 mol / L natural pH (pH 5) gave the highest removal percentage value of eriochrome T black color with 63.74 % removal in 20 minutes of contact. In evaluating the effect of varying the pH of Eriochrome black T solution in the adsorption process, it was found that the more acidic the environment, the greater the percentage stain removal, being a result of acid-base interaction between the adsorbate and the adsorbent. In T Eriochrome black removal study in real effluent we used the optimized conditions by studying with synthetic sewage. The dye removal at pH 10, natural pH of the effluent was no significant reaching the maximum amount of color removal percentage of 8.12%, obtained already at pH 3 with maximum color removal 100.00% of color, once more proving that eriochrome black T and effectively interact better with the adsorbent at acid pH values (pH 5 or 3), and most efficiently at pH 3. thus one can mention that the perlite expanded (an amorphous aluminosilicate naturally acid) modified with orthophenanthroline (one Bronsted base) consists of a master and effective removal of coloring material in the acid-type aqueous solution, the conditions expressed in this study, can be applied as an adsorbent of this dye also mums real effluent.

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