Banca de DEFESA: JOÃO VICTOR OLIVEIRA NASCIMENTO DA SILVA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : JOÃO VICTOR OLIVEIRA NASCIMENTO DA SILVA
DATE: 19/03/2024
TIME: 10:15
LOCAL: Sala de Aula do PPGRHS
TITLE:

SEMICONTINUOUS PROCESS OF TERTIARY TREATMENT OF CHEESE WHEY USING A MICROALGA-FUNGUS CONSORTIUM IN AERATED REACTOR

KEY WORDS:

Bioremediation, microalga-fungus consortium, semicontinuous, whey

PAGES: 93
BIG AREA: Engenharias
AREA: Engenharia Ambiental
SUBÁREA: Saneamento Básico/Esgotos/Reator Anaeróbico
SUMMARY:

It is estimated that up to 10 L of whey can be generated per kilogram of processed cheese and that there is a significant polluting potential in terms of Chemical Oxygen Demand (COD), Total Nitrogen (TN) and Total Phosphorus (TP). Biological treatment of effluents is one of the most used methods for whey, whether aerobic or anaerobic, given its high biodegradability. In this sense, the objective of this work was to evaluate the treatment of whey (with emphasis on tertiary treatment) in an aerated reactor using the microalgae-filamentous fungus symbiosis (Tetradesmus obliquus LCE-01 and Cunninghamella echinulata) in different organic loads and mode of operation (discontinuous and semi-continuous). The reactors were operated with an aeration rate of 1.5 vvm, pneumatically agitated, at 30-35ºC, evaluated under a light intensity of 100 µmol·m^-2·s^-1. In semi-continuous mode, volumetric replacement rates - TRVs of 40 and 60% were used. The previously characterized whey had values of COD 67,014.48 mg·L^-1, TN 1,377.05 mg·L^-1 and TP 625.60 mg·L^-1. After the secondary (main) biological treatment, carried out with co-culture, reductions in the order of 96.94% for COD, 97.97% for NT and 95.93% for FT were obtained in two sequential stages and 10 days operating totals. After that, advanced treatment analyzes using 3 loads (C1 > C2 > C3) with levels in the range between 1,176.32- 6,355.60 mg·L^-1 for COD, 21.90-77.32 mg·L^-1 TN and 21.95-52.61 mg·L^-1 for TP were evaluated. Preliminary studies (with COD:N:P ratio = 50) showed nitrogen limitation, even with reasonable removal of COD, NT and TF (but within what is required by legislation); which made it possible to continue the study in different DQO:N:P ratios, seeking to improve the performances obtained. Thus, in the next stage, new experiments were carried out with adjustment of the COD:N ratio to values of 20, 30 and 40 in C2 organic loads (initial contents for COD of 2370.46 ± 26.73, and TN of 37.78 ± 1.88 and TP of 21.95 ± 0.11 mg·L^-1) and C3 (initial levels for COD of 1176.32 ± 8.91, TN of 21.97 ± 0.03 and TP of 12.32 ± 0.07 mg·L^-1) and it was shown that there was indeed nitrogen limitation in the previous condition, achieving greater COD and TP removals, with a better COD:N:P ratio between 20-30. In semi-continuous mode at COD:N:P = 20, maximum removals were obtained for TRVs of 40 and 60% and equal to 84.92% for COD, 99.41% for TP and 84.44% for TN. Only the condition with C2 and TRV of 60% that showed a residual TN (due to supplementation) being outside that required by legislation, but for C2 at TRV of 40% and C3 at TRVs of 40 and 60% the process could operate in satisfactory manner in compliance with legislation. There was production of microbial sludge with potential (1-2 g.L^-1) and stabilization of pH during treatment (no need for adjustment).

COMMITTEE MEMBERS:
Interno(a) - 3081569 - CARLOS EDUARDO DE FARIAS SILVA
Interno(a) - 1644323 - KARINA RIBEIRO SALOMON
Externo(a) à Instituição - BRIGIDA MARIA VILLAR DA GAMA - UFAL
Externo(a) à Instituição - GEORGIA NAYANE SILVA BELO GOIS