Banca de DEFESA: LARISSA RODRIGUES MACÁRIO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : LARISSA RODRIGUES MACÁRIO
DATE: 21/03/2024
TIME: 16:30
LOCAL: Sala de Reuniões 01 - LCCV
TITLE:

TERCTIARY TREATMENT OF CHEESE WHEY BY MICROALGA-YEAST CO-CULTURE

KEY WORDS:

whey, Tetradesmus obliquus, Saccharomyces cerevisiae, effluent treatment

PAGES: 72
BIG AREA: Engenharias
AREA: Engenharia Química
SUBÁREA: Processos Industriais de Engenharia Química
SPECIALTY: Processos Bioquímicos
SUMMARY:

In Brazil, dairy factories face similar challenges, with whey, a by-product of cheese production, being a significant source of polluting waste due to its high organic load. To address this, processes such as bioremediation are employed, including aerobic processes (such as activated sludge) and anaerobic processes (anaerobic digestion) during secondary (primary) treatment. In order to treat contaminants that, although reduced in the effluent, still exceed discharge standards, tertiary (advanced or polishing) treatment is employed. In this regard, microalgae can be used, and when combined with other microorganisms such as yeast, they enhance treatment. This approach is effective in nutrient removal, primarily nitrogen and phosphorus, as well as reducing the concentration of chemical oxygen demand (COD). This study aimed to evaluate the treatment of whey through the co-cultivation of Tetradesmus obliquus and Saccharomyces cerevisiae in a batch bubble column reactor aerated at 1.5 vvm and 100 µmol m-2 s-1. Initially, experiments operated with different concentrations of organic loads (300-400, 600-815, 1610, and 3240 mg L-1 for COD, 8-47 for NT, and 2.5-2.89, 5-6, 12, and 25 mg L-1 for TP) for 7 days. Results with the consortium showed higher removal efficiency, achieving removal efficiencies of 94.07% for COD, 95.18% for total phosphorus (TP), and 83.61% for total nitrogen (TN). When yeast was used, maximum removal efficiencies were 78.22%, 77.56%, and 58.09% for COD, TN, and TP, respectively. Residual values for the two lower organic loads for the three parameters were in accordance with the maximum values stipulated by the legislation considered. Biomass growth in the consortium was higher than in yeast monoculture, with values ranging from 72-380 mL-1, proportional to the organic loads used. It was observed that the system, which had a COD:N ratio of 50, was limited by nitrogen, and for this reason, in a later stage, COD:N ratios of 25 and 12.5 were studied for the two lower organic loads. With the new ratios, it was indeed found that nitrogen supplementation enhanced treatment, achieving the same parameters as in the previous stage but reducing the treatment time from 7 to 3 days. It is important to note that microbial sludge growth increased considerably, and pH could be easily controlled. Therefore, bioremediation using the microalgae-yeast consortium demonstrates good technical feasibility for tertiary treatment of this effluent to meet the required standards before discharge into water bodies.

COMMITTEE MEMBERS:
Interno(a) - 3081569 - CARLOS EDUARDO DE FARIAS SILVA
Interno(a) - 1456420 - RENATA MARIA ROSAS GARCIA ALMEIDA
Externo(a) à Instituição - ANA KARLA DE SOUZA ABUD - UFS
Externo(a) à Instituição - FRANCINE PIMENTEL DE ANDRADE - UFAL