Banca de DEFESA: KARINE FONSECA SOARES DE OLIVEIRA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : KARINE FONSECA SOARES DE OLIVEIRA
DATE: 23/03/2021
TIME: 15:00
LOCAL: Sala Virtual (Videoconferência)
TITLE:

Carvão ativo da Casca da Castanha de caju como bioadsorvente de metais em Água Produzida.

KEY WORDS:

Keyword: bioadsorption, metals, agro-industrial waste, biomass and produced water

PAGES: 110
BIG AREA: Engenharias
AREA: Engenharia de Materiais e Metalúrgica
SUMMARY:

The use of biomass for the production of bio-adsorbents has been gaining emphasis in the last decades, since it presents a high performance and a low cost of production, in addition to avoiding waste of the waste and minimizing the environmental problem due to its improper disposal in the place. The cashew nut shell (CNS) is a residue from the processing of cashew almonds, and this process is abundant in the northeastern region of Brazil. The objective of this research is to use a CNS as a bioadsorber of renewable origin, through the valorization of this by-product and, consequently, to promote the local economy with its commercialization. The material was subjected to thermal and chemical treatment, in order to obtain a more efficient bioadsorber. The characterizations performed without material density were, pH (pcz), X-Ray Fluorescence (FRX), Fourrier Transform Infrared Spectroscopy (FTIR), Scanning Electron Microscopy (SEM). Then, the kinetics and adsorption isotherm tests were carried out in mono and multi-element synthetic solutions using Cu²⁺, Pb²⁺ and Cr³⁺ metals, all at room temperature. The adsorption kinetics were evaluated using the mathematical models of pseudo-first order, pseudo-second order and intraparticle diffusion and as isotherms were adjusted following the models of Langmuir, Freundlich and Redlich-Peterson. Then, the fixed bed adsorption study was carried out, as well as the material regeneration. The residual metal ions were formed by Atomic Absorption (AA) spectroscopy. The material treated with NaOH was the one that obtained the best response for the removal of metals, for this material it was carried out in the experimental planning, the optimized end of the material activation, variation of the contact time of the base with the biomass and concentration of NaOH. The FTIR spectra show that there are anionic groups (carboxylics, hydroxyls and amines) on the surface of the bioadsorber and the micrographs of the SEM imposed a heterogeneous, irregular and spongy surface, both positive characteristics for adsorption. The mass used for adsorption was 0.1g with equilibrium time of 3h. A maximum removal of Cu²⁺, Pb²⁺ and Cr³⁺ is 46%, 96% and 56% respectively. In the adsorption kinetics of the model that best fit for the pseudo-second order and requires the predominance of chemisorption as an adsorption mechanism. The Langmuir model was favorable for the adsorption of Cu (II) and Cr (III), whereas the Freundlich model for Pb (II), it is suggested that chemical adsorption occurs in mono and multilayer. The breaking point was 75 mL, 75 mL and 60 mL for Cu²⁺, Pb²⁺ and Cr³⁺ respectively. The desorption of the metal ions retained in the column was efficient using HCl 1.0 mol / L and the regeneration cycle that can be used only one cycle. Thus, it is concluded that the bio-absorbent produced from the cashew nut shell has a high potential for the removal of metals and other contaminants in liquid effluents, since there was no chemical treatment and, consequently, the production cost was low, besides not having generated residues in the solution.

BANKING MEMBERS:
Externa à Instituição - FABIOLA DIAS DA SILVA CURBELO - UFPB
Presidente - 6347420 - MARCUS ANTONIO DE FREITAS MELO
Externa ao Programa - 1979301 - RENATA MARTINS BRAGA
Externo ao Programa - 1995142 - RODRIGO CÉSAR SANTIAGO
Externo à Instituição - VÍTOR RODRIGO DE MELO E MELO - IFPB