Banca de QUALIFICAÇÃO: JAQUELINE DOS SANTOS

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : JAQUELINE DOS SANTOS
DATE: 22/08/2022
TIME: 14:00
LOCAL: Sala virtual (https://meet.google.com/xhr-rmgo-kwr)
TITLE:

Study of semicontinuous process of whey treatment by microalgae in open system

KEY WORDS:

Biological treatment, Tetradesmus obliquus, dairy industry

PAGES: 77
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Processos Industriais de Engenharia Química
SPECIALTY: Processos Bioquímicos
SUMMARY:

The dairy industry is one of the most important sectors of the food industry, generating a large amount of effluents, mainly whey. This effluent is marked by the high concentration of COD (chemical oxygen demand), NT (total nitrogen) and FT (total phosphate), which can, for example, generate eutrophication in water bodies when discarded without proper treatment. Aerobic or anaerobic biological processes are often used, but overall, they often do not remove nitrogen and phosphorus content efficiently. In this sense, microalgae are photosynthetic microorganisms that have high efficiency in the removal of these compounds, and can even apply mixotophy, which also refers to the removal of organic carbon for nutrition, at the same time that photosynthesis is carried out. The cultivation of microalgae can be in open mode (not being axenic) and subject to environmental contamination and closed in photobioreactors. Open systems have the advantage of having lower costs and being able to associate natural microorganisms in symbiotic systems with microalgae for the treatment of effluents. However, the application of microalgae mixotrophy in an open system must assess that, even subject to association with natural contaminants, the organic load and characteristics of the effluent and the process favor their development, and consequently, the advantages of their use. One strategy is the dilution of the effluent, in order to guarantee greater stability (mainly in terms of pH) and to avoid substrate inhibition in microalgae. In this sense, this work aims to evaluate the use of the microalgae Tetradesmus obliquus LCE-01 in the treatment of diluted whey as well as to evaluate the semi-continuous process in an open system without aeration. For this, the remediation process was studied using a concentration of 1% under conditions of magnetic stirring and constant illumination (100 µmol m-2 s-1). The experiment was carried out in batch mode for the first 7 days and then in semi-continuous mode with volumetric replacement rates of 20, 40, 60 and 80% at 3-day volumetric replacement intervals and with a total process time of 16 days with pH between 8-8.5. The experiments were monitored for pH (digital pH gauge), dry weight (gravimetry), COD (dichromate digestion method), NT (Kjedahl method) and FT (ascorbic acid method). The reactor with 80% replacement was the one that obtained the best results in COD, NT with respectively 80% and 70-80% and total phosphate removal of up to 70% for the replacement of 40%. Thus, the results show the potentiality of Tetradesmus obliquus and for the defense, experiments will be carried out with the serum diluted 4% to confirm the results.

BANKING MEMBERS:
Presidente - 3081569 - CARLOS EDUARDO DE FARIAS SILVA
Interna - 1456420 - RENATA MARIA ROSAS GARCIA ALMEIDA
Externa ao Programa - 1296115 - ALBANISE ENIDE DA SILVA