Featured Research

from universities, journals, and other organizations

Danish Eco City proves waste management can reverse greenhouse trend

Date:
December 10, 2009
Source:
SAGE Publications UK
Summary:
Cities can progress from consuming energy and emitting greenhouse gases to actually producing energy while saving on GHG emissions, due to substitution of fossil fuels elsewhere. These findings are based on research in the city of Aalborg in Northern Denmark.

Cities can progress from consuming energy and emitting greenhouse gases (GHG) to actually producing energy while saving on GHG emissions, due to substitution of fossil fuels elsewhere. These findings are based on research in the city of Aalborg in Northern Denmark, published this week in Waste Management & Research, published by SAGE.

Cities following similar waste management strategies are already having a far-reaching impact on GHG emissions in some regions of Europe.

Given the global interest in GHG emissions it is perhaps surprising that to date few scientists have produced studies that measure the impact of waste treatment system changes over the longer term. Tjalfe Poulsen and Jens Aage Hansen from Aalborg University in Denmark used historical data from their own municipality of Aalborg to gain a broader, longer term overview of how a 'joined-up' approach to waste impacts GHG emissions. The assessment included sewage sludge, food waste, yard waste and other organic waste (including paper and plastic).

Aalborg's citizens have already implemented a package of measures to take on waste that benefits the environment. In 1970 Aalborg's municipal organic waste management system resulted in net GHG emissions with methane from landfill accounting for almost 100%. But between 1970 and 2005, the city changed its waste treatment strategy to include yard waste composting, with the city's remaining organic waste incinerated for combined heat and power production. Of this, waste incineration contributed 80% to net energy production and GHG turnover, wastewater treatment (including sludge digestion) contributed another 10%, while other waste treatment processes used (composting, transport, and land application of treated waste) had minor impacts.

"Generally incineration with or without energy production and biogas production with energy extraction are the two most important processes for the overall energy balance mainly due to the substitution of fossil fuel-based energy," says Poulsen.

Poulsen and Hansen calculate that the energy potential tied up in municipal organic waste in Denmark is equivalent to 5% of the country's total energy consumption including transport. The Aalborg municipality represents about four percent of the Danish population.

The researchers also looked forward to 2020, and predict that further improvements are possible by reducing energy consumed by wastewater treatment (for aeration), increasing anaerobic digestion and incineration process efficiency and source separating food waste for anaerobic co-digestion.

Aalborg's progress shows how far reaching waste management can be in reaching energy and GHG goals, and should offer encouragement to other cities embarking on greener waste management strategies for the future.

Within the European Union (EU), municipal waste management has already reduced GHG emissions significantly, from 64 to 28 million tonnes CO2 per year between 1990 and 2007, which is equivalent to a drop from 130 to 60 kg CO2 each year per capita. The EU municipal waste sector will achieve 18 percent of the reduction target set for Europe before 2012 according to the Kyoto agreement. The International Solid Waste Association (ISWA) discusses these findings in its Waste & Climate White Paper, due for publication in December. Looking forward, between 2012 and 2020 the EU municipal waste sector will become a net saver of GHG emissions according to current predictions. Aalborg is not alone among Northern European cities where citizens are already reducing overall GHG emissions thanks to optimised waste management.


Story Source:

The above story is based on materials provided by SAGE Publications UK. Note: Materials may be edited for content and length.


Journal Reference:

  1. Tjalfe G. Poulsen and Jens Aage Hansen. Assessing the impacts of changes in treatment technology on energy and greenhouse gas balances for organic waste and wastewater treatment using historical data. Waste Management & Research, 2009; 27 (9): 861 DOI: 10.1177/0734242X09349557

Cite This Page:

SAGE Publications UK. "Danish Eco City proves waste management can reverse greenhouse trend." ScienceDaily. ScienceDaily, 10 December 2009. <www.sciencedaily.com/releases/2009/11/091130103634.htm>.
SAGE Publications UK. (2009, December 10). Danish Eco City proves waste management can reverse greenhouse trend. ScienceDaily. Retrieved September 19, 2014 from www.sciencedaily.com/releases/2009/11/091130103634.htm
SAGE Publications UK. "Danish Eco City proves waste management can reverse greenhouse trend." ScienceDaily. www.sciencedaily.com/releases/2009/11/091130103634.htm (accessed September 19, 2014).

Share This



More Earth & Climate News

Friday, September 19, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Raw: Wildfires in CA Burn Forest Asunder

Raw: Wildfires in CA Burn Forest Asunder

AP (Sep. 18, 2014) An out-of-control Northern California wildfire has nearly 2,800 people from their homes as it continues to grow, authorities said Thursday. Authorities said a man has been arrested on suspicion of arson for starting the fire on Saturday. (Sept. 18) Video provided by AP
Powered by NewsLook.com
Raw: Elephant Undergoes Surgery in Tbilisi Zoo

Raw: Elephant Undergoes Surgery in Tbilisi Zoo

AP (Sep. 18, 2014) Grand the elephant has successfully undergone surgery to remove a portion of infected tusk at Tbilisi Zoo in Georgia. British veterinary surgeons used an electric drill to extract the infected piece. (Sept. 18) Video provided by AP
Powered by NewsLook.com
Raw: Scientists Examine Colossal Squid

Raw: Scientists Examine Colossal Squid

AP (Sep. 16, 2014) Squid experts in New Zealand thawed and examined an unusual catch on Tuesday: a colossal squid. It was captured in Antarctica's remote Ross Sea in December last year and has been frozen for eight months. (Sept. 16) Video provided by AP
Powered by NewsLook.com
Man Floats for 31 Hours in Gulf Waters

Man Floats for 31 Hours in Gulf Waters

AP (Sep. 16, 2014) A Texas man is lucky to be alive after he and three others floated for more than a day in the Gulf of Mexico when their boat sank during a fishing trip. (Sept. 16) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins