Aeration of the teuftal landfill: Field scale concept and lab scale simulation Marco Ritzkowski a,⇑ , Beat Walker b , Kerstin Kuchta a , Roberto Raga c , Rainer Stegmann a a Institute of Environmental Technology and Energy Economics, Hamburg University of Technology, Harburger Schlossstr. 36, 21079 Hamburg, Germany 1 b Deponie Teuftal AG, Bindenhausstrasse 42d, 3098 Köniz, Switzerland c DII, Department of Industrial Engineering, University of Padua, via Marzolo, 9, 35131 Padova, Italy article info Article history: Received 18 March 2016 Revised 23 May 2016 Accepted 2 June 2016 Available online xxxx Keywords: Landfill aeration Moisturization Post-closure care Bio-stabilization Leachate pollution abstract Long lasting post-closure care (PCC) is often the major financial burden for operators of municipal solid waste (MSW) landfills. Beside costs for the installation and maintenance of technical equipment and bar- riers, in particular long term treatment of leachate and landfill gas has to be paid from capital surplus. Estimations based on laboratory experiments project time periods of many decades until leachate quality allows for direct discharge (i.e. no need for further purification). Projections based on leachate samples derived from the last 37 years for 35 German landfills confirm these assumption. Moreover, the data illus- trate that in particular ammonium nitrogen concentrations are likely to fall below limit values only after a period of 300 years. In order to avoid long lasting PCC the operator of Teuftal landfill, located in the Swiss canton Bern, decided to biologically stabilize the landfill by means of a combined in situ aeration and moisturization approach. In December 2014 the aeration started at a landfill section containing approximately 30% of the total landfill volume. From summer 2016 onwards the remaining part of the landfill will be aerated. Landfill aeration through horizontal gas and leachate drains is carried out for the first time in field scale in Europe. The technical concept is described in the paper. Parallel to field scale aeration, investigations for the carbon and nitrogen turnover are carried out by means of both simulated aerated landfills and simulated anaerobic landfills. The results presented in this paper demonstrate that aeration is capable to enhance, both carbon mobilization and discharge via the gas phase. This effect comes along with a significant increase in bio-stabilization of the waste organic fraction, which positively affects the landfill emission behavior in the long run. In terms of leachate pol- lution reduction it could be demonstrated that the organic load decrease fast and widely independent of the adjusted aeration rates whereby ammonium nitrogen load efficiently decrease later and only under higher aeration rates. Ó 2016 Elsevier Ltd. All rights reserved. 1. Introduction The Teuftal landfill, located in the Swiss canton Bern, is the lar- gest sanitary landfill in Switzerland. For more than 40 years both, municipal solid waste (MSW), construction and demolition waste, bottom ashes, flue gas cleaning residues as well as industrial waste are disposed of at different landfill sections. Untreated MSW has been landfilled between 1973 and 2000 on an area of approxi- mately 12 ha. This section of the landfill which contains approx. 3.2 million tons of waste (approx. 2.1 million tons dry matter) is hereafter referred to as bioreactor. Based on the available records regarding the landfilled waste materials it can be assumed that the amount of organic carbon in the fresh MSW was in a range of 18–20% based on dry mass. Since 1 January 2000, landfilling of organic waste is prohibited in Switzerland (Schweizerischer Bundesrat, 1990). Consequently, the bioreactor has been covered with biologically non-reactive waste (slightly contaminated soil) during the past 16 years. Between 1982, when landfill gas (LFG) collection started for the first time, and 2013 a total of approx. 256 million m 3 LFG at an average methane concentration of 45% (average CO 2 concentra- tion: 32%) has been collected from the bioreactor and used for combined electrical and thermal energy production. Since 1996 the collected amounts of LFG declined significantly down to hourly mean values well below 100 m 3 /h in 2013. At the same time, anal- ysis results for leachate samples taken directly out of the most http://dx.doi.org/10.1016/j.wasman.2016.06.004 0956-053X/Ó 2016 Elsevier Ltd. All rights reserved. ⇑ Corresponding author. E-mail address: m.ritzkowski@tu-harburg.de (M. Ritzkowski). 1 www.tu-harburg.de/iue/. Waste Management xxx (2016) xxx–xxx Contents lists available at ScienceDirect Waste Management journal homepage: www.elsevier.com/locate/wasman Please cite this article in press as: Ritzkowski, M., et al. Aeration of the teuftal landfill: Field scale concept and lab scale simulation. Waste Management (2016), http://dx.doi.org/10.1016/j.wasman.2016.06.004