Banca de QUALIFICAÇÃO: LUCAS ANTONIO DA SILVA DE JESUS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : LUCAS ANTONIO DA SILVA DE JESUS
DATE: 13/03/2024
TIME: 09:00
LOCAL: MODO REMOTO
TITLE:

Application of biomass derived reduced graphene oxide as an adsorbent for different industrial effluents

KEY WORDS:

Adsorption; Graphene; Phenol; Dye; Removal, Biomass.

PAGES: 60
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Processos Industriais de Engenharia Química
SPECIALTY: Processos Orgânicos
SUMMARY:

Graphene and its derivatives have been one of the most promising nanomaterials for industrial applications due to the multifunctionality of their 2D structure. Graphene consists of a single layer of carbon atoms arranged in a two-dimensional hexagonal structure, while one of its derivatives, reduced graphene oxide (rGO), is a structure with defective graphene sheets and can be obtained by bottom-up methods. up or top-down. Due to these unique characteristics, including its high surface area, adsorption capacity and functional groups that facilitate the removal of different pollutants present in industrial effluents, such as heavy metals, dyes and volatile organic compounds. Recently, other carbon precursors have been investigated for alternative sources of graphene synthesis, one of which is biomass. The biomass-derived rGO used was characterized by HRTEM, XRD, Raman, XPS, FTIR, BET and Zeta Potential. Therefore, this study was divided into three stages: In the first stage, the behavior of this rGO as an adsorbent to remove phenol from water was evaluated. And at this stage of the study, a removal of approximately 99% of phenol in water was obtained, with a maximum adsorption capacity (Qmax) of 240 mg/g, using 10 mg of rGO in an initial phenol concentration of 200 mg\L in 120 min, with pH 8.0 and temperature of 30ºC, these values are higher than those found in the literature. In the second stage (II), the behavior of rGO in the adsorption of a basic cationic dye, Methylene Blue (AM), was evaluated. In this second stage of the study, the best result obtained was an efficiency in dye removal of 99%, with 50 mg of rGO, a dye concentration of 80 mg/L in 130 min, with pH 3.0 and a temperature of 30ºC. The maximum adsorption capacity (Qmax) was 495.7 mg/g. In the first two stages of this study, the Freundlich isotherm was the most appropriate, with a value of R2 0.99 for both models, demonstrating that adsorption occurs in multilayers on a heterogeneous surface, a direct relationship with the amount of sheets present in the rGO. The kinetic study of the two stages demonstrated that the pseudo-second order model is the most appropriate to describe the behavior of both, with an R2= 0.99. In the thermodynamic study, both stages presented positive enthalpy values (∆H°) confirming the endothermic nature of the reaction, with decreasing values of Gibbs free energy (∆G°) indicating that with increasing temperature, there is better efficiency. in the removal of both effluents. Furthermore, the positive entropy values (∆S°) indicate that a solid/liquid randomness occurs in the adsorption process. In the third stage of this study (III), the behavior of rGO as an adsorbent for trichomy disperse dyes, dyes applied in the dyeing of polyester textile fibers, which is the second most consumed fiber in the world, will be evaluated. In this final stage, batch adsorption studies will also be carried out, and the best conditions for experimental parameters, isotherm, kinetic and thermodynamic studies and the reuse of effluent in a polyester dyeing process will be evaluated.

COMMITTEE MEMBERS:
Interno - 1584174 - DOMINGOS FABIANO DE SANTANA SOUZA
Presidente - 2941160 - JOSE HERIBERTO OLIVEIRA DO NASCIMENTO
Externo ao Programa - ***.778.283-** - RAFAEL BARBOSA RIOS - UFERSA