Banca de DEFESA: ELISSON ANDRADE DE SOUZA

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
DISCENTE : ELISSON ANDRADE DE SOUZA
DATA : 04/09/2020
HORA: 14:30
LOCAL: Sala virtual Conferências web RNP
TÍTULO:

TREATMENT OF TANNERY SLUDGE WITH SIMULTANEOUS HYDROGEN GENERATION USING BIFUNCTIONAL PHOTOCATALYTIC SYSTEMS AND OTHER ADVANCED OXIDATION PROCESSES

PALAVRAS-CHAVES:

Tannery wastewater, photocatalysis, hydrogen, Advanced Oxidation Processes, CdS/ZnO composites, Reduced Graphene Oxide

PÁGINAS: 117
GRANDE ÁREA: Ciências Exatas e da Terra
ÁREA: Química
SUBÁREA: Química Inorgânica
ESPECIALIDADE: Foto-Química Inorgânica
RESUMO:

Producing hydrogen from photocatalytic treatment of leather tannery sludge is a sustainable form of clean energy generation, low cost and waste employability, promoting green chemistry. Besides, the sunlight incidence on the Earth's surface is more than enough for the energy needs of the planet, which is composed of about 43% of visible light. Thus, this work proposes the use of tannery waste obtained from liming bath step, rich in sodium sulfide, to act as a sacrificial reagent and (CdS)_x/(ZnO)_y composites as a photocatalyst in photocatalytic visible light-assisted hydrogen production employing reduced graphene oxide (RGO) as a cocatalyst. The liming bath sludge, aim of this study, was selected because of its high sulfur content (73.0 g kg^-1) and total organic carbon (430.0 g kg^-1), which can act as sacrificial reagents in photocatalytic hydrogen production. At 50% (v/v) residue and pH ≥ 13, the photocatalysts RGO/(CdS)_1,0/(ZnO)_0,4 and RGO/(CdS)_1,0/(ZnO)_0,73/(ZnS)_0,57 showed the best performance for hydrogen production, of 1,6 mmol g^-1_cat h^-1 and 1,4 mmol g^-1_cat h^-1, respectively, mitigating of 80-90% of the sulfide content in the tannery wastewater. Long-term reaction tests indicated that the photocatalysts remain photoactive for a period of 24 hours, and retain photoactivity after three photocatalytic cycles. The materials have demonstrated great potential for application in energy recovery from tanning wastewater with simultaneous sulfide abatement using sunlight. The photocatalyst RGO/(CdS)_1,0/(ZnO)_0,73/(ZnS)_0,57 should be highlighted because it is more eco-friendly due to the lower Cd content and minimal leaching of this toxic metal during photocatalytic treatment. Despite hydrogen production and sulfide abatement, not all pollutants are mitigated in this process. Thus, Advanced Oxidative Processes (AOP) were employed, using 70% H₂O₂ to degrade the recalcitrant organic matter. Through optimization by the Doehlert matrix, the Sono-Fenton process was identified as the most efficient, promoting a COD reduction around 95% in 30 min.

MEMBROS DA BANCA:
Interno - 1299469 - LUCIANA ALMEIDA DA SILVA
Interno - 659.324.555-00 - MARCOS DE ALMEIDA BEZERRA - UFF
Interno - 2362069 - RAILDO ALVES FIUZA JUNIOR
Interno - 1100392 - SORAIA TEIXEIRA BRANDAO
Externo à Instituição - ALEX ANTONIO CONCEIÇÃO SANTIAGO
Externo à Instituição - SUZANA MODESTO DE OLIVEIRA BRITO - UEFS