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Previous issue date: 2017-03-03 / A necessidade de diversifica??o das formas de tratamento da ?gua de diferentes fontes e para fins diversos revela-se mais urgente a cada dia, sobretudo quando s?o considerados os impactos econ?micos e sociais associados ao manejo de um recurso natural insubstitu?vel. As argilas podem ser aplicadas no abrandamento de ?guas duras, ampliando as perspectivas de aproveitamento e reuso de ?guas, com o desenvolvimento de dispositivos e processos tecnol?gicos sustent?veis. Neste estudo, al?m das que foram mantidas sem tratamento, amostras de bentonita foram ativadas com HCl e H2SO4, enquanto amostras de vermiculita foram modificadas com HCl, NaOH e NaCl, para ensaios de adsor??o de ?ons Ca2+ utilizando solu??o padr?o de c?lcio e ?guas duras reais coletadas adequadamente de po?os da regi?o central do estado do Rio Grande do Norte, Brasil. Uma redu??o de 22,8 % na dureza da solu??o padr?o de c?lcio foi verificada com bentonita ativada com H2SO4, enquanto efici?ncia mais elevada foi comprovada com vermiculitas tratadas com HCl, NaOH e NaCl, com redu??es nas durezas da solu??o padr?o de c?lcio de 43,6 %, 46,3 % e 57,5 %, respectivamente, e redu??o de at? 45,2 % na dureza de amostra real, com a vermiculita modificada com NaCl, que gerou os melhores resultados. Foi comprovado que ? poss?vel recondicionar a vermiculita, bem como atestar que a concentra??o do eletr?lito e tratamento sucessivo influenciam na capacidade adsortiva dessa argila modificada com NaCl. O tratamento salino da vermiculita pode ser feito, de forma simult?nea, com uma combina??o de Na+ e K+ como c?tions troc?veis. As modifica??es realizadas nas argilas foram rastreadas com an?lises de DRX, MEV, TG, DTG, EDX, BET e medida de par?metros f?sico-qu?micos. Novas pesquisas devem ser estimuladas para o refinamento de t?cnicas e m?todos que apliquem argilas na recupera??o e gerenciamento dos recursos h?dricos. / The need to diversify the ways of treating water from different sources and for
different purposes becomes more urgent every day, especially when considering the
economic and social impacts associated with management of an irreplaceable
natural resource. Clays can be applied for softening hard water, expanding
perspectives of water use, with the development of sustainable technological devices
and processes. In this study, in addition to those that were kept untreated, bentonite
samples were activated with HCl and H2SO4, while vermiculite samples were
modified with HCl, NaOH and NaCl, for adsorption tests of Ca2+ ions using standard
calcium solution and real hard water adequately collected from wells in the central
region of the state of Rio Grande do Norte, Brazil. A reduction of 22.8% in the
hardness of the standard calcium solution was verified with H2SO4-activated
bentonite, while higher efficiency was verified with vermiculites treated with HCl,
NaOH and NaCl, with hardness reductions on the standard calcium solution of
43.6%, 46.3% and 57.5%, respectively, and reduction of up to 45.2% in the hardness
of the field-collected samples, with NaCl-modified vermiculite, which generated the
best results. It has been proven that it is possible to recondition the vermiculite, and
that electrolyte concentration and successive treatment influence the adsorptive
capacity of this NaCl-modified clay. Vermiculite saline treatment can be performed
simultaneously with a combination of Na+ and K+ as exchangeable cations. Clay
modifications were tracked with XRD, SEM, TG, DTG, EDX and BET analyzes, as
well as the determination of physicochemical parameters.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/22683 |
| Date | 03 March 2017 |
| Creators | Lima, Roberto Rodrigues Cunha |
| Contributors | 42314070453, http://lattes.cnpq.br/1595902438130772, Ara?jo, Antonio Souza de, 35530502415, Fernandes, Nedja Suely, 44420773472, http://lattes.cnpq.br/9563490368583906, Coriolano, Ana Catarina Fernandes, 83744479404, http://lattes.cnpq.br/5552621403067808, Castro, Francisco Laerte de, 77862589491, http://lattes.cnpq.br/2913544384537886, Fernandes J?nior, Valter Jos? |
| Publisher | PROGRAMA DE P?S-GRADUA??O EM CI?NCIA E ENGENHARIA DE MATERIAIS, UFRN, Brasil |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/doctoralThesis |
| 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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