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Hybrid alkali-hydrodynamic disintegration of waste-activated sludge before two-stage anaerobic digestion process

The first step of anaerobic digestion, the hydrolysis, is regarded as the rate-limiting step in the degradation of complex organic compounds, such as waste-activated sludge (WAS). The aim of lab-scale experiments was to pre-hydrolyze the sludge by means of low intensive alkaline sludge conditioning...

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Autores principales: Grübel, Klaudiusz, Suschka, Jan
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Springer Berlin Heidelberg 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4432092/
https://www.ncbi.nlm.nih.gov/pubmed/25318422
http://dx.doi.org/10.1007/s11356-014-3705-y
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author Grübel, Klaudiusz
Suschka, Jan
author_facet Grübel, Klaudiusz
Suschka, Jan
author_sort Grübel, Klaudiusz
collection PubMed
description The first step of anaerobic digestion, the hydrolysis, is regarded as the rate-limiting step in the degradation of complex organic compounds, such as waste-activated sludge (WAS). The aim of lab-scale experiments was to pre-hydrolyze the sludge by means of low intensive alkaline sludge conditioning before applying hydrodynamic disintegration, as the pre-treatment procedure. Application of both processes as a hybrid disintegration sludge technology resulted in a higher organic matter release (soluble chemical oxygen demand (SCOD)) to the liquid sludge phase compared with the effects of processes conducted separately. The total SCOD after alkalization at 9 pH (pH in the range of 8.96–9.10, SCOD = 600 mg O(2)/L) and after hydrodynamic (SCOD = 1450 mg O(2)/L) disintegration equaled to 2050 mg/L. However, due to the synergistic effect, the obtained SCOD value amounted to 2800 mg/L, which constitutes an additional chemical oxygen demand (COD) dissolution of about 35 %. Similarly, the synergistic effect after alkalization at 10 pH was also obtained. The applied hybrid pre-hydrolysis technology resulted in a disintegration degree of 28–35 %. The experiments aimed at selection of the most appropriate procedures in terms of optimal sludge digestion results, including high organic matter degradation (removal) and high biogas production. The analyzed soft hybrid technology influenced the effectiveness of mesophilic/thermophilic anaerobic digestion in a positive way and ensured the sludge minimization. The adopted pre-treatment technology (alkalization + hydrodynamic cavitation) resulted in 22–27 % higher biogas production and 13–28 % higher biogas yield. After two stages of anaerobic digestion (mesophilic conditions (MAD) + thermophilic anaerobic digestion (TAD)), the highest total solids (TS) reduction amounted to 45.6 % and was received for the following sample at 7 days MAD + 17 days TAD. About 7 % higher TS reduction was noticed compared with the sample after 9 days MAD + 15 days TAD. Similar results were obtained for volatile solids (VS) reduction after two-stage anaerobic digestion. The highest decrease of VS was obtained when the first stage, the mesophilic digestion which lasted 7 days, was followed by thermophilic digestion for 17 days.
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spelling pubmed-44320922015-05-19 Hybrid alkali-hydrodynamic disintegration of waste-activated sludge before two-stage anaerobic digestion process Grübel, Klaudiusz Suschka, Jan Environ Sci Pollut Res Int Effective Management of Sewage Sludge The first step of anaerobic digestion, the hydrolysis, is regarded as the rate-limiting step in the degradation of complex organic compounds, such as waste-activated sludge (WAS). The aim of lab-scale experiments was to pre-hydrolyze the sludge by means of low intensive alkaline sludge conditioning before applying hydrodynamic disintegration, as the pre-treatment procedure. Application of both processes as a hybrid disintegration sludge technology resulted in a higher organic matter release (soluble chemical oxygen demand (SCOD)) to the liquid sludge phase compared with the effects of processes conducted separately. The total SCOD after alkalization at 9 pH (pH in the range of 8.96–9.10, SCOD = 600 mg O(2)/L) and after hydrodynamic (SCOD = 1450 mg O(2)/L) disintegration equaled to 2050 mg/L. However, due to the synergistic effect, the obtained SCOD value amounted to 2800 mg/L, which constitutes an additional chemical oxygen demand (COD) dissolution of about 35 %. Similarly, the synergistic effect after alkalization at 10 pH was also obtained. The applied hybrid pre-hydrolysis technology resulted in a disintegration degree of 28–35 %. The experiments aimed at selection of the most appropriate procedures in terms of optimal sludge digestion results, including high organic matter degradation (removal) and high biogas production. The analyzed soft hybrid technology influenced the effectiveness of mesophilic/thermophilic anaerobic digestion in a positive way and ensured the sludge minimization. The adopted pre-treatment technology (alkalization + hydrodynamic cavitation) resulted in 22–27 % higher biogas production and 13–28 % higher biogas yield. After two stages of anaerobic digestion (mesophilic conditions (MAD) + thermophilic anaerobic digestion (TAD)), the highest total solids (TS) reduction amounted to 45.6 % and was received for the following sample at 7 days MAD + 17 days TAD. About 7 % higher TS reduction was noticed compared with the sample after 9 days MAD + 15 days TAD. Similar results were obtained for volatile solids (VS) reduction after two-stage anaerobic digestion. The highest decrease of VS was obtained when the first stage, the mesophilic digestion which lasted 7 days, was followed by thermophilic digestion for 17 days. Springer Berlin Heidelberg 2014-10-16 2015 /pmc/articles/PMC4432092/ /pubmed/25318422 http://dx.doi.org/10.1007/s11356-014-3705-y Text en © The Author(s) 2014 https://creativecommons.org/licenses/by/4.0/ Open Access This article is distributed under the terms of the Creative Commons Attribution License which permits any use, distribution, and reproduction in any medium, provided the original author(s) and the source are credited.
spellingShingle Effective Management of Sewage Sludge
Grübel, Klaudiusz
Suschka, Jan
Hybrid alkali-hydrodynamic disintegration of waste-activated sludge before two-stage anaerobic digestion process
title Hybrid alkali-hydrodynamic disintegration of waste-activated sludge before two-stage anaerobic digestion process
title_full Hybrid alkali-hydrodynamic disintegration of waste-activated sludge before two-stage anaerobic digestion process
title_fullStr Hybrid alkali-hydrodynamic disintegration of waste-activated sludge before two-stage anaerobic digestion process
title_full_unstemmed Hybrid alkali-hydrodynamic disintegration of waste-activated sludge before two-stage anaerobic digestion process
title_short Hybrid alkali-hydrodynamic disintegration of waste-activated sludge before two-stage anaerobic digestion process
title_sort hybrid alkali-hydrodynamic disintegration of waste-activated sludge before two-stage anaerobic digestion process
topic Effective Management of Sewage Sludge
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4432092/
https://www.ncbi.nlm.nih.gov/pubmed/25318422
http://dx.doi.org/10.1007/s11356-014-3705-y
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