Banca de DEFESA: Ivanilson da Silva de Aquino
Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.STUDENT : Ivanilson da Silva de Aquino
DATE: 04/06/2024
TIME: 14:30
LOCAL: Sala de Informática do PTARH com Transmissão pela Plataforma MS Teams
TITLE:
Evaluation of the Presence of Microplastics in the Brasília Norte Sewage Treatment Plant and the Potential for Removal by Magnetic Iron Oxide Nano-Powder Functionalized with Citric Acid (NP-Fe3O4@AC)
KEY WORDS:
Microplastics, Magnetic nano-powder, Removal, Sewage treatment plant.
PAGES: 140
BIG AREA: Engenharias
AREA: Engenharia Sanitária
SUBÁREA: Recursos Hídricos
SUMMARY:
Microplastics (MPs) pollution is a growing concern due to the accumulation of these materials in the environment. In this study, spot samples from nine sampling in the wastewater treatment plant (WWTP Norte) Brasília Norte were analyzed. To identify microplastics in samples, several methods and procedures have been developed and evaluated, including the production of reference microplastics, resistance of polymers to digestive methods, and particle extraction. The procedure selected for sample treatment was materialized by a digestion step of Fenton's reagent organic matter, followed by density separation with ZnCl2 solution. Microplastic identification was carried out visually (microscopy) and assisted by chemical analysis using FTIR-ATR spectroscopy. The results showed the significant presence of microplastics, especially textile fibers, of different shapes and colors, in different particle sizes in all treatment units evaluated, with a majority composition of HDPE and LDPE. Furthermore, quantification revealed that the WWTP Norte released the final effluent at a concentration of 150 ±18 MP/L into Lake Paranoá. Additionally, in this study magnetic nano-powders based on iron oxide functionalized with citric acid (NP-Fe3O4@AC) were used to remove a consortium of microplastics composed of HDPE, LDPE and PP in proportions 1:1:1. The coprecipitation method was used to synthesize NP-Fe3O4@AC, which was characterized in terms of morphology (SEM), majority crystalline phase (XRD), chemical aspects (FTIR), and surface area (nitrogen sorption isotherms). The microplastic removal efficiency of NP-Fe3O4@AC was investigated as a function of initial concentration, contact time, and pH. The Sips equation and pseudo-second order model were the ones that best fit the experimental data of the isotherm and adsorption kinetics, respectively. NP-Fe3O4@AC removed 80% of the MPs at pH 6. From experimental observations (zeta potential, porosity, and SEM) and theoretical considerations, it was concluded that the mechanisms of hydrogen bonding, pore filling, and van der Waals forces were predominant in the removal of microplastics. The reuse tests indicated that NP-Fe3O4@AC could be reused up to five times, and the removal efficiency remained above 50%. These results indicate that NP-Fe3O4@AC is a viable alternative for possible applications aimed at removing microplastics from wastewater.
COMMITTEE MEMBERS:
Externa à Instituição - MIRIAM CRISTINA SANTOS AMARAL - UFMG
Presidente - 1512988 - ARIUSKA KARLA BARBOSA AMORIM
Interna - 1122604 - CRISTINA CELIA SILVEIRA BRANDAO
Interna - 1646057 - YOVANKA PEREZ GINORIS