Removing organic matter from sulfate-rich wastewater via sulfidogenic and methanogenic pathways.
The simultaneous organic matter removal and sulfate reduction in synthetic sulfate-rich wastewater was evaluated for various chemical oxygen demand (COD)/sulfate ratios applied in a horizontal-flow anaerobic immobilized sludge (HAIS) reactor. At higher COD/sulfate ratios (12.5 and 7.5), the removal of organic matter was stable, likely due to methanogenesis. A combination of sulfate reduction and methanogenesis was clearly established at COD/sulfate ratios of 3.0 and 1.9. At a COD/sulfate ratio of 1.0, the organic matter removal was likely influenced by methanogenesis inhibition. The quantity of sulfate removed at a COD/sulfate ratio of 1.0 was identical to that obtained at a ratio of 1.9, indicating a lack of available electron donors for sulfidogenesis. The sulfate reduction and organic matter removal were not maximized at the same COD/sulfate ratio; therefore, competitive inhibition must be the predominant mechanism in establishing an electron flow.
Department of Hydraulic and Sanitation Engineering, Escola de Engenharia de São Carlos, Universidade de São Paulo, Av. Trabalhador São-Carlense, 400, São Carlos - São Paulo, Brazil E-mail: eforesti@sc.usp.br.
Rogerio Silveira
RS
Vilela
Department of Hydraulic and Sanitation Engineering, Escola de Engenharia de São Carlos, Universidade de São Paulo, Av. Trabalhador São-Carlense, 400, São Carlos - São Paulo, Brazil E-mail: eforesti@sc.usp.br.
Márcia Helena Rissato Zamariolli
MH
Damianovic
Department of Hydraulic and Sanitation Engineering, Escola de Engenharia de São Carlos, Universidade de São Paulo, Av. Trabalhador São-Carlense, 400, São Carlos - São Paulo, Brazil E-mail: eforesti@sc.usp.br.
Eugenio
E
Foresti
D019149:Bioreactors; D008697:Methane / Q000737:chemistry / Q000378:metabolism*; D013431:Sulfates / Q000737:chemistry*; D014865:Waste Disposal, Fluid / Q000379:methods*; D014874:Water Pollutants, Chemical / Q000737:chemistry*
D013431:Sulfates; D014874:Water Pollutants, Chemical; D008697:Methane