Banca de DEFESA: MARCOS ADRIANO MARQUES PESSÔA SALES
Uma banca de DEFESA de DOUTORADO foi cadastrada pelo programa.STUDENT : MARCOS ADRIANO MARQUES PESSÔA SALES
DATE: 16/11/2023
TIME: 08:30
LOCAL: Pós-Graduação Engenharia Civil
TITLE:
KEY WORDS:
Photogranules, C/N ratio, Photo-respirometry, nitrogen mass balance
PAGES: 121
BIG AREA: Engenharias
AREA: Engenharia Civil
SUMMARY:
Aerobic granular sludge (AGS) and microalgal-bacteria granular consortia (MBGC) are wastewater treatment technologies, based on self-aggregation, capable to treat organic matter and nutrients simultaneously in a single reactor. The granulation conditions, biomass composition and granular stability differ from one region to another due to differences found in the composition of sanitary sewage and climatic conditions. In the MBGC, symbiosis occurs, where bacteria produce CO2 assimilated by the algae, which makes O2 available to the bacteria. However, information about the effect of algae on granulation and granular stability is still limited, as well as microalgae-bacteria interactions in granular reactors. In this context, the present work studied: (I) the effect of different operational conditions on the development of AGS and MBGC, and the role of microalgae in the formation of MBGC; (II) nitrogen balance to differ the consumption of this nutrient by microalgae and bacteria; (III) oxygen balance in LGAB to evaluate the contribution of each microbial group in the O2 balance during effluent treatment. In the first study (I) different influent carbon/nitrogen ratios (C/N, 4/1 and 8/1), and feeding modes (40 min and 60 min non-aerated feeding) were applied in 4 reactors in sequential batches with 4-hour cycles. The LGA was formed 15 days before the LGAB. However, the consortium biomass generally showed better stability and diameter. Under C/N=4 ratio, LGA showed a higher abundance of microorganisms producing extracellular polymeric substances (EPS), such as Xanthomonadacea and Rhodocyclaceae. The formed biomasses were unable to completely remove the high concentration of NH4+-N (100mg/L). Under C/N=8, NH4+-N removals greater than 90% it was observed, and the 60 min non-aerated feed cycle resulted in higher total nitrogen removal. In the second study (II), it was observed that in systems with microalgal-bacterial consortium, microalgae perform greater nitrogen uptake (205 mg N-NH4+/d) compared to nitrifying bacteria (24.14 mgNH4+-N /d), being the main responsible for the removal of nitrogen in the consortium. In the third study (III), it was observed that the amount of O2 produced by microalgae (37 mgO2/gVSS/h) was higher than that required by bacteria (23.87 mgO2/gVSS/h), demonstrating that the system is sustainable if applied to effluents with a C/N ratio = 10/1, similar to sewage in a tropical climate region such as those found in Brazil.
COMMITTEE MEMBERS:
Externo à Instituição - ANDRE BEZERRA DOS SANTOS - UFC
Presidente - 1528727 - SAVIA GAVAZZA DOS SANTOS PESSOA
Externa à Instituição - SHYRLANE TORRES SOARES VERAS - UFPE
Externa ao Programa - 1654048 - SIMONE MACHADO SANTOS - nullExterno à Instituição - TIAGO ROGERIO VITOR AKABOCI