The effect of slime accumulated in a long-term operating UASB using crude glycerol to treat S-rich wastewater
| Autor: | Xudong Zhou, Eva Fernández-Palacios, Antoni D. Dorado, Javier Lafuente, Xavier Gamisans, David Gabriel |
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| Přispěvatelé: | Universitat Politècnica de Catalunya. Departament d'Enginyeria Minera, Industrial i TIC, Universitat Politècnica de Catalunya. RIIS - Grup de Recerca en Recursos i Indústries Intel·ligents i Sostenibles |
| Jazyk: | angličtina |
| Rok vydání: | 2024 |
| Předmět: |
Environmental Engineering
Glycerol fermentation Enginyeria química::Química del medi ambient [Àrees temàtiques de la UPC] Sewage--Purification--Biological treatment Granular sludge Environmental Chemistry Sulfate reduction Aigües residuals--Depuració--Tractament biològic General Medicine Slime-like substances Removal efficiency General Environmental Science Sludge flotation |
| Popis: | Altres ajuts: acords transformatius de la UAB An up-flow anaerobic sludge blanket (UASB) reactor targeting sulfate reduction was operated under a constant TOC/S-SO 4 2− ratio of 1.5 ± 0.3 g C/g S for 639 days using crude glycerol as carbon source. A filamentous and fluffy flocculant material, namely slime-like substances (SLS), was gradually accumulated in the bioreactor after the cease of methanogenic activity. The accumulation of SLS was followed by a decrease in the removal efficiencies and a deterioration in the performance. Selected characteristics of SLS were investigated to explore the causes of its formation and the effect of SLS on the UASB performance. Results showed that glycerol fermentation and sulfate reduction processes taking place in the reactor were mainly accomplished in the bottom part of the UASB reactor, as the sludge concentration in the bottom was higher. The accumulation of SLS in the UASB reactor caused sludge flotation that further led to biomass washout, which decreased the sulfate and glycerol removal efficiencies. Batch activity tests performed with granular sludge (GS), slime-covered granular sludge (SCGS) and SLS showed that there was no difference between GS and SLS in the mechanism of glycerol fermentation and sulfate reduction. However, the specific sulfate reduction rate of GS was higher than that of SLS, while SLS showed a higher glycerol fermentation rate than that of GS. The different rates in GS and SLS were attributed to the higher relative abundances of fermentative microorganisms found in SLS and higher relative abundances of sulfate reducing bacteria (SRB) found in GS. |
| Databáze: | OpenAIRE |
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