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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.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/20285 |
| Date | 01 July 2015 |
| Creators | Almeida, Janiele Mayara Ferreira de |
| Contributors | 44420773472, http://lattes.cnpq.br/9563490368583906, Guedes, Ana Paula de Melo Alves, 03330987499, http://lattes.cnpq.br/5738717177200782, Pimentel, Patricia Mendon?a, 77858239449, http://lattes.cnpq.br/9303372770390061, Pergher, Sibele Berenice Castella, 50942611004, http://lattes.cnpq.br/5249001430287414, Fernandes, Nedja Suely |
| Publisher | Universidade Federal do Rio Grande do Norte, PROGRAMA DE P?S-GRADUA??O EM QU?MICA, UFRN, Brasil |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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