Banca de DEFESA: MARILIA MARQUES VELLOSO DA SILVEIRA

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : MARILIA MARQUES VELLOSO DA SILVEIRA
DATE: 31/01/2023
TIME: 09:00
LOCAL: Programa de Pós-Graduação em Engenharia Civil
TITLE:

Study of Co-digestion of Glycerol, vinasse, and Microalgae Applying Simplex Ccentroid Design

KEY WORDS:

1,3-propanediol; acetic acid; chain elongation; Actinobaculum; Clostridium.

PAGES: 90
BIG AREA: Engenharias
AREA: Engenharia Civil
SUMMARY:

In recent decades, waste production from biofuel industries and sewage treatment plants has increased significantly with the world's energy demand and population increase in many countries. In this scenario, the sustainable management of large amounts of waste also becomes increasingly challenging. In the present study, experiments were carried out with 300-mL anaerobic reactors for the co-digestion of glycerol (G), sugarcane vinasse (V), and microalgae biomass (M) in a single batch. The objective was to evaluate its potential for use in the production of products with added value, treating organic waste, and avoiding environmental pollution if disposed off improperly. The conditions for the mixtures were chosen through the centroid simplex experimental design, and all mixtures' metabolite concentrations were determined by liquid chromatography. Analysis of the concentration data resulted in two response surface models that describe the effect of substrate mix ratio on overall yield and concentration, respectively, of 1,3-propanediol (1,3-PDO) and acetic acid. The models obtained revealed that the yield of 1,3-PDO (mol 1,3-PDO.mol^-1 gly) was influenced in different ways by varying the mixing proportions: test 4 (50%G; 50%V) (0.63); test 5 (50%G; 50%M) (0.47), and test 7 (33%G; 33%V; 33%M) (0.60). Practically, all tests had yields superior to test 1 (100%G) (0.42). An important occurrence was the elongation of the chain for valeric and caproic acids in tests 1, 2 (100%V), and 4. Although the binary and ternary mixtures were not synergistic, the concentration of acetic acid was higher mainly in the mixtures with the presence of glycerol and vinasse, tests 8 (66%G; 17%V; 17%M); 9 (17%G; 66%V; 17%M) and 5. This indicates that G, V, and M can be co-digested without compromising the overall yield of 1,3-PDO, making the application of co-digestion more flexible. Genera such as Actinobaculum, Clostridium, Parabacteroides, and Sporanaerobacter were predominant in the tests. Overall results suggest that anaerobic co-digestion is a viable means for the simultaneous treatment and recovery of mixtures of G, V, and M, which are important organic wastes.

COMMITTEE MEMBERS:
Externa à Instituição - CAMILA APARECIDA DE MENEZES - IFCE
Externo à Instituição - LUCIANO MATOS QUEIROZ - UFBA
Presidente - 3199298 - MAURICIO ALVES DA MOTTA SOBRINHO