University of Oulu

Sari Piippo, Maria Lauronen, Heini Postila, Greenhouse gas emissions from different sewage sludge treatment methods in north, Journal of Cleaner Production, Volume 177, 2018, Pages 483-492, ISSN 0959-6526,

Greenhouse gas emissions from different sewage sludge treatment methods in north

Saved in:
Author: Piippo, Sari1; Lauronen, Maria2; Postila, Heini2
Organizations: 1Energy and Environmental Engineering, University of Oulu, P.O. BOX 4300, FI-90014, Finland
2Water Resources and Environmental Engineering, University of Oulu, P.O. BOX 4300, FI-90014, Finland
Format: article
Version: accepted version
Access: open
Online Access: PDF Full Text (PDF, 0.7 MB)
Persistent link:
Language: English
Published: Elsevier, 2018
Publish Date: 2019-12-27


The most sustainable method for treating sewage sludge depends strongly on the situation and local circumstances. In sparsely populated northerly areas are demanding boundary conditions, e.g. cold and long winter, long transport distances and low amounts of generated sludge. In this study, commonly used calculators and emissions coefficients for calculating the greenhouse gas (GHG) emissions from sewage sludge treatment methods were assessed to create a calculator suitable for the Northern Finland context. The calculator was then used to determine which sewage sludge treatment method (composting, anaerobic digestion (AD), incineration (with and without thermal drying)) resulted in the lowest emissions of the GHG gases in different situations in Northern Finland. GHG gases included carbon dioxide (CO₂; including biobased), methane (CH₄) and nitrous oxide (N₂O), measured as carbon dioxide equivalents (CO₂eq). According to the calculator, AD generated the least CO₂eq emissions of all treatment methods studied. The second best option was incineration of sludge without thermal drying, while the third best was composting or incineration of sludge after thermal drying with e.g. fossil or other fuels. Most of the emissions were generated from the treatment process itself and the share of emissions generated during transport was minimal, despite the long transport distances when all CO₂ emissions (incl. biobased) were considered. The role of users of the end-products and the possibility to use the CO₂ generated were highly important when considering environmental perspective. These results can be utilised when selecting the locally most suitable method. In future, some of the treatment methods (i.e. AD, incineration) with CO₂ capture could be considered carbon sinks, as they also remove biobased CO₂ emissions.

see all

Series: Journal of cleaner production
ISSN: 0959-6526
ISSN-E: 1879-1786
ISSN-L: 0959-6526
Volume: 177
Pages: 483 - 492
DOI: 10.1016/j.jclepro.2017.12.232
Type of Publication: A1 Journal article – refereed
Field of Science: 218 Environmental engineering
Funding: This work was supported as part of the project “Innovations for CO2 and bioeconomy - greenhouse gases from sludge treatments and novel C1 products”, which was funded by the ERDF and the Centre for Economic Development, Transport and the Environment for North Ostrobothnia. The other funders were two wastewater purification plants, Lakeuden Keskuspuhdistamo Oy and Oulu Waterworks, Oulun jätehuolto, NC Partnering Oy and Gasum Biotehdas Oy.
Dataset Reference: The following is the supplementary data related to this article:
Copyright information: © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http:/