Banca de QUALIFICAÇÃO: ROBERTO RODRIGUES CUNHA LIMA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ROBERTO RODRIGUES CUNHA LIMA
DATA : 27/01/2017
HORA: 09:00
LOCAL: Sala de Aula PPGCEM
TÍTULO:

Environmental technology: Modify Clays applied for softening hard water

PALAVRAS-CHAVES:

 Bentonite. Vermiculite. Hard water. Environmental technology.

PÁGINAS: 85
GRANDE ÁREA: Engenharias
ÁREA: Engenharia de Materiais e Metalúrgica
RESUMO:

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 real sample, 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, BET and physical-chemical parameter measurements. Further research should be encouraged for the refinement of techniques and methods applying clays for the recovery and management of water resources.

 

MEMBROS DA BANCA:
Externo ao Programa - 350509 - ANTONIO SOUZA DE ARAUJO
Externo à Instituição - FRANCISCO LAERTE DE CASTRO - CTGás
Presidente - 1149328 - VALTER JOSE FERNANDES JUNIOR