Banca de DEFESA: MARCELO BRUNO DE OLIVEIRA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MARCELO BRUNO DE OLIVEIRA SILVA
DATE: 20/01/2023
TIME: 09:00
LOCAL: On-line
TITLE:

CHITOSAN CRYOGEL WITHOUT AND WITH MICROCELLULOSE FOR REMOVAL OF POTENTIALLY TOXIC METAL IONS IN WASTEWATER

PAGES: 120
BIG AREA: Outra
AREA: Multidisciplinar
SUMMARY:

Among the emerging contaminants in aquatic environments, potentially toxic metal ions are of great concern due to their potentially devastating effect on the environment. In this sense, this work aimed to develop cryogels of chitosan without and with microcellulose, using residual chitosan of crustacean exoskeleton, aiming at the production of these environmentally friendly and economically attractive cryogels for the removal of Cr⁶⁺ and  Zn²⁺ ions of residual water. The development of cryogel was carried out in three stages. Initially, chitosan was obtained from the shrimp exoskeleton by chemical method. In the second stage, microcellulose was obtained from eucalyptus residue. Finally, cryogels composites of chitosan without and with microcellulose by crosslinking with glutaraldehyde were developed, followed by freeze-drying. The chitosan obtained presented a high degree of deacetylation. In addition, the microwave deacetylation process uses less time and energy than the conventional method, allowing less environmental impact. The treatment of eucalyptus residue allowed the removal of lignin and hemicellulose. The combined shear action of a blender and high-intensity ultrasonication allowed the obtaining of microcellulose with good suspension stability. The cryogels developed presented irregular and interconnected pores, favoring high surface area. Notably, the incorporation of microcellulose allowed greater thermal and mechanical stability to the cryogels. Sorption investigation indicates good affinity of cryogels with  Cr⁶⁺ ions, with maximum sorption capacity above 60 mg.g^-1, but low affinity with Zn²⁺.

COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 1671275 - DERVAL DOS SANTOS ROSA
Membro Titular - Examinador(a) Interno ao Programa - 1761120 - DANILO JUSTINO CARASTAN
Membro Titular - Examinador(a) Externo à Instituição - ALEXANDRE TADEU PAULINO - UDESC
Membro Suplente - Examinador(a) Interno ao Programa - 1676364 - JULIANA MARCHI
Membro Suplente - Examinador(a) Externo ao Programa - 015.548.626-80 - Talles Barcelos da Costa - UNICAMP