Banca de DEFESA: JÉSSICA CAMILA DO NASCIMENTO ROCHA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : JÉSSICA CAMILA DO NASCIMENTO ROCHA
DATE: 27/02/2023
TIME: 14:00
LOCAL: Pós-Graduação Engenharia Civil
TITLE:

Disinfection of Effluents with Chlorine: Fformation of Trihalomethanes and Microbial Inactivation

KEY WORDS:

Disinfection. Wastewater. Trihalomethanes.Chlorine. Inactivation.

PAGES: 91
BIG AREA: Engenharias
AREA: Engenharia Civil
SUMMARY:

Chlorine is one of the most used chemical agents during the disinfection process. However, the disinfection ofsewage is not yet a Brazilian reality. Low investments in basic sanitation combined with centralized treatment systemscontribute to the non-universalization of sewage services in Brazil. Therefore, the search for innovative andcompetitive technologies with conventional methods constitutes an important step to spread disinfection in WWTPs.In this sense, electroactivated water (EAW), produced by electrolysis of a brine, has emerged as a suitable alternativefor this purpose. This oxidizing solution is composed of sodium hypochlorite, hydrogen peroxide and ozone. Inaddition to the high efficiency in microbial inactivation, EAW does not have additional costs with transport and storageof chemical products, as it is produced at the place of use and the only necessary inputs are water, salt and energy. However, chlorination triggers the formation of DBPs, compounds formed from the interaction of halogens (chlorine,iodine or bromine) with organic matter. These compounds have carcinogenic, genotoxic and mutagenic potential.Thus, this work aimed to study the feasibility of applying this sanitizer in domestic sewage. For this, ideal operatingconditions were optimized in jar tests to determine the effects of sanitizer type and dosage and contact time. Theformation of DBPs, microbial inactivation and physical-chemical characteristics were monitored during the disinfectionprocess. The redox potential increased in almost all assays. Conductivity increased after chlorination, except whenusing EAW. The turbidity reduced significantly. TS raised specifically for EAW. As for the TSS, the values suffered asignificant drop compared to the initial state. For COD, it is possible to perceive differences between twoquantification methodologies used: in one, there was an increase in COD, while in the other it remained stable ordecreased. For ammoniacal nitrogen, it was possible to notice that there was consumption of the same by chlorine,forming chloramines. As for chlorides, there was a great discrepancy in the use of EAW compared to other oxidants.As for THM, it was possible to observe that all disinfectant agents presented the formation of the main THMs reportedin the literature. TCM was the by-product generated in greater quantity. As for microbial inactivation, all three oxidantsshowed satisfactory results. In short, EAW proved to be a very competitive chemical oxidant with commerciallyavailable chemical agents.

COMMITTEE MEMBERS:
Presidente - 3133998 - BRUNA SCANDOLARA MAGNUS
Externo à Instituição - JOSE ROBERTO SANTO DE CARVALHO - UFPE
Externo à Instituição - MIGUEL MANSUR AISSE - UFPR