Banca de DEFESA: RAFAEL FELIPE SILVA SOUTO

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : RAFAEL FELIPE SILVA SOUTO
DATE: 29/01/2021
TIME: 09:00
LOCAL: videoconferência
TITLE:

Evaluation of an activated sludge system integrated with rotating biological contactor as post treatment of UASB reactor on carbon and nitrogen removal.

KEY WORDS:

AS hybrid system; post-treatment; nitrification; biological carbon removal; biological nitrogen removal

PAGES: 49
BIG AREA: Engenharias
AREA: Engenharia Sanitária
SUBÁREA: Tratamento de Águas de Abastecimento e Residuárias
SUMMARY:

The activated sludge (AS) system is born from a secular concept applied to wastewater treatment and is widely spread around the world. Although its high efficiency, several AS based alternative systems are explored in order to optimize, for instance, organic material removal, enhance nitrification and nitrogen removal, sedimentation and reduce area requirements. Thus, combined suspended and attached growth (hybrid systems) in aerated systems presents itself as a relevant alternative in the global picture. In warm regions, such as Brazil, the combination of AS and hybrid AS systems as UASB reactors post treatment is largely applied, as the association allows savings in aeration, reduction of sludge production and no need of a sludge digestion unit. That said, the purpose of this work was to evaluate the performance of a full-scale domestic wastewater treatment plant (WWTP) configurated with a AS system integrated with RBC as a post treatment for UASB reactors, in view of its design conception. For this, data from physical-chemical analyzes and quantitative and qualitative microscopic observation of the microfauna carried out during the years of 2017 and 2020 were evaluated. The results show that the WWTP started to operate in an overload state before it reached project horizon (2024 year) and also it does not reach the project estimated efficiencies for BOD, COD and NH4+, which were 94%, 90% and 50%, respectively. The BOD removal during the period of evaluation was 83% (median), while COD and NH4+ removal were 81% and 38%, in that order. Overload in secondary clarifiers and failure in the nitrification process were also observed. In addition, it was found that the anoxic chambers (CA) and the aeration tanks (AT) worked with hydraulic retention times (HRT) below of what project has determined: observed CA HRT ranged from 27 to 44% of project CA HRT, and observed AT HRT ranged from 54 to 56% of project AT HRT. The short HRT applied in AS units may be related with poor flocs formation and low density of protozoans and metazoans. The calculation of the hydraulic loading rate points to an overload in terms of clarification in 49% of the measurements made, while the overload percentual of solids loading rate was 14%.      

 

BANKING MEMBERS:
Presidente - 3919045 - JULIANA DELGADO TINOCO
Interna - 3057847 - SILVÂNIA LUCAS DOS SANTOS
Externo ao Programa - 2550052 - PAULO EDUARDO VIEIRA CUNHA
Externo à Instituição - Antônio Pedro de Oliveira Netto - UFAL