Effects of anaerobic pre-treatment on the degradation of dewatered-sewage sludge
(2009) In Renewable Energy 34(7). p.1795-1800- Abstract
- Effects of anaerobic pre-treatment were evaluated on the dewatered-sewage sludge from a municipal wastewater treatment plant in order to improve its biodegradability through anaerobic digestion. The pre-treatment was conducted in laboratory scale at 25, 50 and 70 degrees C for an incubation time of two days. As a reference, sludge sample was also autoclaved at 121 degrees C for 20 min to determine the thermal effect to the subsequent sludge digestion. Characteristics of dewatered-sludge such as viscosity, pH and soluble chemical oxygen demand (SCOD) were affected by the pre-treatment. A higher SCOD after the pretreatment did not necessarily imply an increase in methane yield, although initial biodegradability rate was improved. In fact, a... (More)
- Effects of anaerobic pre-treatment were evaluated on the dewatered-sewage sludge from a municipal wastewater treatment plant in order to improve its biodegradability through anaerobic digestion. The pre-treatment was conducted in laboratory scale at 25, 50 and 70 degrees C for an incubation time of two days. As a reference, sludge sample was also autoclaved at 121 degrees C for 20 min to determine the thermal effect to the subsequent sludge digestion. Characteristics of dewatered-sludge such as viscosity, pH and soluble chemical oxygen demand (SCOD) were affected by the pre-treatment. A higher SCOD after the pretreatment did not necessarily imply an increase in methane yield, although initial biodegradability rate was improved. In fact, a 'great' improvement in SCOD concentration (up to 27%) was translated in only 8% increase in the methane yield (298 +/- 9 and 276 +/- 6 Nml CH4 gVS(added)(-1) for pre-treated and untreated samples, respectively). Increasing the anaerobic pre-treatment time from 12 h to 2 days at 50 degrees C led to an 11% improvement in methane yield. Methane content in biogas increased from an average of 65-69% for the pre-treated and untreated substrates, respectively. Volatile solids (VS) reduction increased from 42% to 51%. The overall digestion time was not affected by the pre-treatment but 90% of methane was produced in the first 12 days of incubation for 50 degrees C pre-treated samples whereas it took 2-5 days more for 25, 70 degrees C pre-treated and untreated sludge samples. In this study, thermophilic digestion was also found to be a better option in terms of faster digestion and higher VS-reduction, but it showed lower methane yield as compared to mesophilic digestion, i.e. 9% and 11% increment in methane yields for thermophilic and mesophilic digestions, respectively. (C) 2008 Elsevier Ltd. All rights reserved. (Less)
Please use this url to cite or link to this publication:
https://lup.lub.lu.se/record/1400877
- author
- Ivo Achu, Nges LU and Liu, Jing LU
- organization
- publishing date
- 2009
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Thermophilic, Pre-treatment, Methane yield, Anaerobic digestion, Mesophilic, VS-reduction
- in
- Renewable Energy
- volume
- 34
- issue
- 7
- pages
- 1795 - 1800
- publisher
- Elsevier
- external identifiers
-
- wos:000264739200017
- scopus:60949098908
- ISSN
- 0960-1481
- DOI
- 10.1016/j.renene.2008.12.001
- language
- English
- LU publication?
- yes
- id
- 24031791-5f02-43af-95a0-3d010214be86 (old id 1400877)
- date added to LUP
- 2016-04-01 11:41:07
- date last changed
- 2021-06-23 04:25:39
@article{24031791-5f02-43af-95a0-3d010214be86,
abstract = {Effects of anaerobic pre-treatment were evaluated on the dewatered-sewage sludge from a municipal wastewater treatment plant in order to improve its biodegradability through anaerobic digestion. The pre-treatment was conducted in laboratory scale at 25, 50 and 70 degrees C for an incubation time of two days. As a reference, sludge sample was also autoclaved at 121 degrees C for 20 min to determine the thermal effect to the subsequent sludge digestion. Characteristics of dewatered-sludge such as viscosity, pH and soluble chemical oxygen demand (SCOD) were affected by the pre-treatment. A higher SCOD after the pretreatment did not necessarily imply an increase in methane yield, although initial biodegradability rate was improved. In fact, a 'great' improvement in SCOD concentration (up to 27%) was translated in only 8% increase in the methane yield (298 +/- 9 and 276 +/- 6 Nml CH4 gVS(added)(-1) for pre-treated and untreated samples, respectively). Increasing the anaerobic pre-treatment time from 12 h to 2 days at 50 degrees C led to an 11% improvement in methane yield. Methane content in biogas increased from an average of 65-69% for the pre-treated and untreated substrates, respectively. Volatile solids (VS) reduction increased from 42% to 51%. The overall digestion time was not affected by the pre-treatment but 90% of methane was produced in the first 12 days of incubation for 50 degrees C pre-treated samples whereas it took 2-5 days more for 25, 70 degrees C pre-treated and untreated sludge samples. In this study, thermophilic digestion was also found to be a better option in terms of faster digestion and higher VS-reduction, but it showed lower methane yield as compared to mesophilic digestion, i.e. 9% and 11% increment in methane yields for thermophilic and mesophilic digestions, respectively. (C) 2008 Elsevier Ltd. All rights reserved.},
author = {Ivo Achu, Nges and Liu, Jing},
issn = {0960-1481},
language = {eng},
number = {7},
pages = {1795--1800},
publisher = {Elsevier},
series = {Renewable Energy},
title = {Effects of anaerobic pre-treatment on the degradation of dewatered-sewage sludge},
url = {http://dx.doi.org/10.1016/j.renene.2008.12.001},
doi = {10.1016/j.renene.2008.12.001},
volume = {34},
year = {2009},
}