Banca de DEFESA: FERNANDO JOSÉ VIEIRA DA CUNHA FILHO

Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.
STUDENT : FERNANDO JOSÉ VIEIRA DA CUNHA FILHO
DATE: 18/02/2020
TIME: 09:00
LOCAL: AUDITÓRIO DO NUPEG
TITLE:

The role of the optimized excess of H2O2 in the rapid mineralization rate of the drugs Acetyl Salicylic Acid (AAS) and Hydrochlorothiazide (HCT) via the photo-Fenton process

KEY WORDS:

pharmaceutical pollutants; emerging pollutants; factorial planning; toxicity, photo-Fenton.

PAGES: 140
BIG AREA: Engenharias
AREA: Engenharia Química
SUMMARY:

Studies of drugs as emerging pollutants have been gaining importance in the scientific community. Acetylsalicylic acid (AAS) is a model pollutant and a representative of emerging pharmaceutical micropollutants whose mineralization through various advanced oxidative processes (POAs) takes hours to complete. Hydrochlorothiazide (HCT) has been found in final waters for consumption due to its persistence. This work is dedicated to optimize and understand the kinetic conditions to mineralize AAS and HCT using the Foto-Fenton process with UVA radiation in a tubular photochemical reactor and mixing reactor, respectively. The optimization employs a statistical factor planning tool that studies how the concentrations of the pharmaceutical contaminant, Fe2 + and H2O2 affect mineralization over a range of concentrations. The factorial design indicates that the initial concentration of H2O2 is a crucial variable to achieve a rapid rate of AAS and HCT mineralization. Using optimized content of H2O2 and Fe2 + in the photo-Fenton process (H2O2 / Fe2 + / UVA and H2O2 / Fe2 + / UVC, respectively), a mineralization of more than 90% for AAS and 100% for HCT is achieved in about 10 minutes and 30 minutes, respectively. The underlying reason for such remarkable performance is attributed to the optimized excess of [H2O2], which varies according to the contaminant, that is, the H2O2 concentration ratio used in the initial time for the required complete mineralization of the theoretical TOC. Measurements of the remaining H2O2 concentration strongly indicate that the excess of [H2O2] optimizes the instantaneous concentration of the radical • OH. Among the applied POA's, the comparison of UV-H2O2 oxidation (H2O2 / UVA and H2O2 / UVC) with photo-Fenton oxidation (H2O2 / Fe2 + / UVA and H2O2 / Fe2 + / UVC) stands out. When using the optimized peroxide in the first composition, almost 100% degradation of AAS and HCT was obtained, but in this case, there was no good mineralization. To obtain a high degree of mineralization, close to 100% it was crucial to add Fe2 + together with the aid of light. In addition, a toxicology study was conducted with HCT. HCT has been shown to be toxic at certain concentrations for the Mysidaceas group. The LC50 of 37.25 mg.L-1 of HCT was determined. The POA’s were applied to determine the possibility of generating their own means for the survival of the Mysidaceas. It was obtained that among the POA’s, as only the photo-Fenton (H2O2 / Fe2 + / UVC) was able to mineralize the HCT, it was the only POA to make the medium no more toxic. This fact corroborates with results of the total non-mineralization of the other applied POA's, comparing that in these cases there was the formation of toxic intermediates. And the only really efficient process for HCT was photo-Fenton (H2O2 / Fe2 + / UVC). In conclusion, the stoichiometric excess of [H2O2], is the most important parameter to be optimized in order to achieve the highest degree of mineralization in the shortest time of use of the photochemical reactor, also decreasing the costs related to the total energy consumed by both the lamp and pumping.

BANKING MEMBERS:
Presidente - 1149554 - OSVALDO CHIAVONE FILHO
Externo ao Programa - 2524058 - DOUGLAS DO NASCIMENTO SILVA
Externa à Instituição - ANDRESSA BASTOS DA MOTA LIMA - USP
Externa à Instituição - DANNIELLE JANAINNE DA SILVA - UFRN
Externo à Instituição - EDSON LUIZ FOLETTO - UFSM