| Autor: |
Santos AMD; Fundação Getúlio Vargas (FGV-Energia), Rio de Janeiro, Brazil.; Federal University of Catalão (UFCAT), Catalão, Brazil.; Laboratory of Anaerobic Biotechnology - Science and Technology Institute, Federal University of Alfenas (UNIFAL-MG), Poços de Caldas, Brazil., Costa JM; School of Chemical Engineering, University of Campinas, Campinas, Brazil., Braga JK; Laboratory of Anaerobic Biotechnology - Science and Technology Institute, Federal University of Alfenas (UNIFAL-MG), Poços de Caldas, Brazil., Flynn TM; California Department of Water Resources, West Sacramento, CA, USA., Brucha G; Laboratory of Anaerobic Biotechnology - Science and Technology Institute, Federal University of Alfenas (UNIFAL-MG), Poços de Caldas, Brazil., Sancinetti GP; Laboratory of Anaerobic Biotechnology - Science and Technology Institute, Federal University of Alfenas (UNIFAL-MG), Poços de Caldas, Brazil., Rodriguez RP; Laboratory of Anaerobic Biotechnology - Science and Technology Institute, Federal University of Alfenas (UNIFAL-MG), Poços de Caldas, Brazil. |
| Abstrakt: |
The competition between sulfate-reducing bacteria and methane-producing archaea has a major influence on organic matter removal, as well as the success of sulfidogenic systems. This study investigated the performance of six batch sulfidogenic reactors in response to different COD/sulfate ratios (1.0 and 2 . 0) and electron donors (cheese whey, ethanol, and sodium lactate) by evaluating the biochemical mechanisms of sulfate reduction, organic matter oxidation, and microbial structure modification. A COD/sulfate ratio of 1.0 resulted in high sulfidogenic activity for all electron donors, thereby achieving a nearly 80% sulfate removal. Lactate provided high sulfate removal rates at COD/sulfate ratios of 1.0 (80%) and 2.0 (90%). A COD/sulfate ratio of 2.0 decreased the sulfate removal rates by 25 and 28% when ethanol and cheese whey were used as substrates. The sulfate-reducing bacteria populations increased using ethanol and lactate at a COD/sulfate ratio of 1.0. Particularly, Desulfovibrio, Clostridium , and Syntrophobacter were predominant . Influent composition and COD/sulfate ratio influenced the relative abundance of the microbial communities. Therefore, controlling these parameters may facilitate the wastewater treatment with high sulfate levels through bacterial activity. |
