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Previous issue date: 2012-10-07 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The contamination by metal ions has been occurring for decades through the
introduction of liquid effluent not treated, mainly from industrial activities, rivers and lakes,
affecting water quality. For that the effluent can be disposed in water bodies, environmental
standards require that they be adequately addressed, so that the concentration of metals does
not exceed the limits of standard conditions of release in the receptor. Several methods for
wastewater treatment have been reported in the literature, but many of them are high cost and
low efficiency. The adsorption process has been used as effective for removal of metal ions.
This paper presents studies to evaluate the potential of perlite as an adsorbent for removing
metals in model solution. Perlite, in its natural form (NP) and expanded (EP), was
characterized by X-ray fluorescence, X-ray diffraction, surface area analysis using nitrogen
adsorption (BET method), scanning electron microscopy and Fourier transform infrared
spectroscopy. The physical characteristic and chemical composition of the material presented
were appropriate for the study of adsorption. Adsorption experiments by the method of finite
bath for model solutions of metal ions Cr3+, Cu2+, Mn2+ and Ni2+ were carried out in order to
study the effect of pH, mass of the adsorbent and the contact time on removal of ions in
solution. The results showed that perlite has good adsorption capacity. The NP has higher
adsorption capacity (mg g-1) than the EP. According to the values of the constant of
Langmuir qm (mg g-1), the maximum capacity of the monolayer was obtained and in terms of
proportion of mass, we found the following order experimental adsorption: Cr3+ (2.194 mg g-
1) > Ni2+ (0.585 mg g-1) > Mn2+ (0.515 mg g-1) > Cu2+ (0.513 mg g-1) and Cr3+ (1.934 mg g-1)>
Ni2+ (0.514 mg g-1) > Cu2+ (0.421 mg g-1) > Mn2+ (0.364 mg g-1) on the NP and EP,
respectively. The experimental data were best fitted the Langmuir model compared to
Freundlich for Cu2+, Mn2+ and Ni2+. However, for the Cr3+, both models fit the experimental
data / A contamina??o por ?ons met?licos vem ocorrendo h? d?cadas atrav?s do lan?amento
de efluentes l?quidos n?o tratados, principalmente de atividades industriais, nos rios e lagos,
comprometendo a qualidade da ?gua. Para que os efluentes possam ser descartados em corpos
d'?gua, as normas ambientais exigem que os mesmos sejam adequadamente tratados, de modo
que a concentra??o dos metais n?o ultrapasse os limites de condi??es padr?es de lan?amento
no corpo receptor. V?rios m?todos para tratamento de efluentes t?m sido apresentados na
literatura, por?m muitos deles s?o de alto custo e baixa efici?ncia. O processo de adsor??o
vem sendo utilizado como eficaz para remo??o de ?ons met?licos. Neste trabalho s?o
apresentados estudos para avaliar a potencialidade da perlita como adsorvente na remo??o de
metais em solu??o modelo. A perlita, na sua forma natural (PN) e expandida (PE), foi
caracterizada por fluoresc?ncia de raios X, difra??o de raios X, an?lise da ?rea superficial
usando adsor??o f?sica de nitrog?nio (m?todo BET), microscopia eletr?nica de varredura
(MEV) e espectroscopia de infravermelho com transformada de Fourier (FTIR). As
caracter?sticas f?sicas e a composi??o qu?mica apresentadas pelo material foram adequadas
para o estudo de adsor??o. Ensaios de adsor??o pelo m?todo de banho finito para solu??es
modelo dos ?ons met?licos Cr3+, Cu2+, Mn2+ e Ni2+ foram realizados, com intuito de estudar o
efeito do pH, da massa do adsorvente e do tempo de contato na remo??o de ?ons em solu??o.
Os resultados demonstraram que a perlita apresenta boa capacidade de adsor??o. A PN
apresenta maior capacidade de adsor??o (mg g-1) do que a PE. De acordo com os valores da
constante de Langmuir, qm (mg g-1), a capacidade m?xima da monocamada foi obtida e em
termos de propor??o de massa, encontrou-se a seguinte ordem experimental de adsor??o: Cr3+
(2,384 mg g-1) > Ni2+ (0,585 mg g-1) > Mn2+ (0,515 mg g-1) > Cu2+ (0,513 mg g-1) sobre a PN
e Cr3+ (1,932 mg g-1) > Ni2+ (0,514 mg g-1) > Cu2+ (0,421 mg g-1) > Mn2+ (0,364 mg g-1)
sobre a PE. Os dados experimentais se ajustaram melhor ao modelo de Langmuir em rela??o
ao de Freundlich para os ?ons Cu2+, Mn2+ e Ni2+. No entanto, para os ?ons Cr3+, ambos, os
modelos se ajustaram adequadamente aos dados experimentais
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/17752 |
| Date | 07 October 2012 |
| Creators | Belarmino, Loilde Damasceno |
| Contributors | CPF:06117988320, http://lattes.cnpq.br/3318871716111536, Huitle, Carlos Alberto Martinez, CPF:01139059980, http://lattes.cnpq.br/2485073932883264, Barbosa, Celmy Maria Bezerra de Menezes, CPF:07355912372, http://lattes.cnpq.br/5606017652367088, Silva, Marta L?gia Pereira da, CPF:03494566402, http://lattes.cnpq.br/3899623847910065, Fernandes, Nedja Suely, Melo, Dulce Maria de Ara?jo |
| Publisher | Universidade Federal do Rio Grande do Norte, Programa de P?s-Gradua??o em Qu?mica, UFRN, BR, F?sico-Qu?mica; Qu?mica |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| Format | application/pdf |
| 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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