Avaliação do desempenho de sistema de tratamento de esgoto sanitário composto de reator UASB seguido de lodo ativado: estudo de caso da ETE Betim Central-MG

• Ano de defesa: 2016
• Autor(a) principal: Pollyane Diniz Saliba
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: Meio Ambiente e Recursos Hídricos; Saneamento; Biorreatores; Nitrificação; Engenharia sanitária; Águas residuais Purificação Processo de lodo ativado
• Link de acesso: http://hdl.handle.net/1843/BUBD-AC2G74

The aim of this study is to evaluate, in real scale, the behavior of a system consisting a reactor UASB followed by activated sludge for treatment of domestic sewage. The facilities in Betim Central Wastewater Treatment Plant, located in the state of Minas Gerais and capable of treating an average flow of 514 L/s, were chosen as subject. The station is operated by the Sanitation Company of Minas Gerais - COPASA, being supervised with the aid of measurements and physical-chemical and bacteriological analyzes. The study consisted in treating statistically the station monitoring data from July 2010 (operational beginning of the WWTP) to July 2014. The results suggest that the system is well suited for the treatment of sewage, presenting high global average removal efficiencies of BOD (94%), COD (91%), ammonia (76%), settling solids (95%) and total suspended solids (92%). However, as expected, this system, as designed, was not effective on the removal of the nutrients, phosphate (34%) and nitrogen (38%), and coliforms (99.84%). Regarding the release pattern of BOD, COD, settleable solids and suspended solids for the state of Minas Gerais, the final effluent from the WWTP was able to serve them fully throughout the monitoring period, except for the parameter settleable solids that still had a high compliance (95%). Despite of being scaled for the conventional activated sludge, at the beginning, Betim Central WWTP operated with standard conditions of extended aeration system, due to the low affluent load. Furthermore, no influence of the operating parameters and design on the quality of the effluent was observed, in terms of organic matter removal, except for the affluent BOD load to the aeration tank and the sludge age. The temperature was one of the factors that influenced nitrification most, with average efficieny of 76%. The conditions of the sludge age and the A/M relation for nitrification of reactor UASB effluent were attended in most part of monitoring period. The denitrification in Betim Central WWTP happened modestly (62%), however, exceeded expectations considering the project (30%). It was observed the proper digestion of the sludge, and the dewatering was within the stated range for centrifuges, producing a cake with an average concentration of 23% of solids.