Estudo dos processos de formação, acumulação, emissão e oxidação de sulfeto de hidrogênio em reatores UASB tratando esgotos domésticos

• Ano de defesa: 2009
• Autor(a) principal: Roberto Meireles Gloria
• 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; Engenharia sanitária
• Link de acesso: http://hdl.handle.net/1843/ENGD-7YALAM

The research aimed at monitoring hydrogen sulfide and its possible points of emission to the atmosphere, allowing a better knowledge and understanding of sulfide routes through UASB reactors treating domestic wastewater. The experiments were conducted in demonstration- (V = 14 m3) and pilot- (V = 360 litres) scale UASB reactors, both fed on sewage from Belo Horizonte city. The demonstration-scale reactor was operated at a HDT of 11 hours (operational condition 1), while the pilot-scale reactor was operated at HDT of 7 and 5 hours (operational conditions 2 and 3, respectively). Sulfate concentration in the liquid phase and sulfide in the liquid and gas phases were monitored, besides other parameters of interest. Batch tests in bench-scale reactors inoculated with scum and cyanobacteria were also carried out, in order to evaluate the potential of biological oxidation of sulfide by organisms present in the scum layer. The median influent concentrations of sulfate, for all three operating conditions, varied between 42.5 and 45.4 mg/L. As for the effluent, the concentrations ranged from 8.8 to 13.2 mg/L. The median influent concentration of sulfide, during all three operational conditions, was 1.2 mg/L. As for the effluent, the concentrations ranged between 7.8 and 10.8 mg/L. In general, the sulfide concentrations in the gas phase were high for the biogas (between 400 and 2100 ppm) and much lower for the residual gas from the settling compartment (between 15 and 100 ppm). In addition, a dissipation device installed in the effluent tubing of the UASB reactor presented a good removal efficiency of sulfide, around 50%. The volatilization of sulfide generated a concentration in the head space of around 300 ppm.The concentration profile of hydrogen sulfide along the demonstration- and pilot-scale reactors indicated that the scum layer did not play an important role in controlling odours, however, the results obtained in bench-scale reactors suggest that the microorganisms present in the scum can promote the oxidation of sulfides.