Banca de QUALIFICAÇÃO: LUCAS GORITO DOS SANTOS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : LUCAS GORITO DOS SANTOS
DATE: 10/10/2023
TIME: 14:00
LOCAL: https://conferenciaweb.rnp.br/webconf/wagner-27
TITLE:

NITRATE REMOVAL IN AQUEOUS SOLUTIONS BY ADSORPTION PROCESSES IN CLAY CARBON COMPOSITES

PAGES: 30
BIG AREA: Ciências Exatas e da Terra
AREA: Química
SUBÁREA: Química Inorgânica
SPECIALTY: Físico Química Inorgânica
SUMMARY:

Nitrate is a pollutant present in all surface and groundwater due to its high solubility in water. The excess of nitrate in aquatic environments poses a potential threat to ecosystems and human health by contributing to eutrophication and causing severe methemoglobinemia (blue baby syndrome). In this context, the present project, which involves the adsorption of nitrate in aqueous solutions, proposed the preparation of the following adsorbents: (1) Glycerol charcoal, hydrothermally carbonized in the presence of concentrated H2SO4 (95-99%) and FeCl3(s); (2) TechPhos/Sludge Composites. Solids (1) and (2) were subjected to a thermal treatment under N2 and/or NH3 flow (ammonization) at different temperatures (400-800°C). The materials were characterized by techniques such as elemental analysis (CHNS), Zeta Potential, Fourier Transform Infrared Spectroscopy (FT-IR), X-ray Photoelectron Spectroscopy (XPS) and N2 adsorption. The TechPhos/Sludge-based materials had poorly developed porous structure (surface area < 34m2/g) and little or no nitrate retention capacity under scientific conditions. An analysis of the glycerol charcoals revealed that before the ammonization step there was the development of a porous structure (652 m2/g) and iron nanoparticles were present (1,14% of Fe), however, the solid did not present the ability to adsorb nitrate under the studied conditions. The ammonization step was responsible for developing the nitrate retention capacity on the glycerol charcoals. Low ammonization temperatures (400°C) promote N2 groups (amino/imine/amide – 92,09%), without significantly impacting the adsorption capacity of CG01-NH3-400 (0,18 mg/g), its porosity (558 m2/g) or pHPCZ<1. At 600°C, there was no structural development, groups N1 (pyridine – 66,81%) predominated, with the appearance of N3 (pyrrole/lactam/pyridone/aniline) and N5 (pyridine oxide), raising its pHPCZ to 3,2 and favoring the adsorption of nitrate on the CG01-NH3-600 (1,97 mg/g). Ammonization at 800°C did not cause the insertion of nitrogenous groups, however, the treatment favored greater development of porosity in CG01-NH3-800 (1034 m2/g) and a higher pHPCZ (3,4), resulting in the greater retention capacity of nitrate among all the materials (2,84 mg/g). During the next steps, it is intended to carry out a Thermogravimetric (TGA), X-ray Diffraction (XRD) and Inductively Shielded Plasma (ICP) analysis of the ammonized glycerol charcoals, as well as the XPS of these solids after nitrate adsorption. Furthermore, it is planned to obtain its adsorption kinetics and isotherms (pH, nitrate concentration and adsorbent:nitrate ratio) and, finally, to carry out nitrate removal tests in real domestic sewage

COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 1601156 - WAGNER ALVES CARVALHO
Membro Titular - Examinador(a) Externo à Instituição - GEÓRGIA CHRISTINA LABUTO ARAÚJO - UNIFESP
Membro Titular - Examinador(a) Externo à Instituição - GABRIELA TUONO MARTINS XAVIER
Membro Suplente - Examinador(a) Interno ao Programa - 1762430 - DALMO MANDELLI