Proyecto Compost

Waste Management 26 (2006) 62–70 www.elsevier.com/locate/wasman

Carbon dioxide and ammonia emissions during composting of mixed paper, yard waste and food waste
Dimitris P. Komilis
a b

a,*

, Robert K. Ham

b

Department of Environmental Engineering, Democritus University of Thrace, Xanthi 67100, Greece Department of Civil and Environmental Engineering, University ofWisconsin-Madison, 53706 Madison, WI, USA Accepted 8 December 2004 Available online 21 February 2005

Abstract The objective of the work was to provide a method to predict CO2 and NH3 yields during composting of the biodegradable fraction of municipal solid wastes (MSW). The compostable portion of MSW was simulated using three principal biodegradable components, namely mixed paper wastes, yard wastes and foodwastes. Twelve laboratory runs were carried out at thermophilic temperatures based on the principles of mixture experimental and full factorial designs. Seeded mixed paper (MXP), seeded yard waste (YW) and seeded food waste (FW), each composted individually, produced 150, 220 and 370 g CO2–C, and 2.0, 4.4 and 34 g NH3–N per dry kg of initial substrate, respectively. Several experimental runs werealso carried out with different mixtures of these three substrates. The effect of seeding was insignificant during composting of food wastes and yard wastes, while seeding was necessary for composting of mixed paper. Polynomial equations were developed to predict CO2 and NH3 (in amounts of mass per dry kg of MSW) from mixtures of MSW. No interactions among components were found to be significant whenpredicting CO2 yields, while the interaction of food wastes and mixed paper was found to be significant when predicting NH3 yields. Ó 2005 Elsevier Ltd. All rights reserved.

1. Introduction Composting of municipal solid wastes (MSW) can be used to pretreat MSW prior to landfilling or to produce a soil amendment and landscaping material (Diaz et al., 1993). Two major biological products during MSWcomposting are carbon dioxide (CO2) and ammonia (NH3). CO2 is a greenhouse gas, while ammonia is an air pollutant of malodorous and potentially toxic nature. Even though MSW consist of many types of organic and inorganic materials, paper wastes, yard wastes and food wastes are the principal biodegradable components, rendering them responsible for most of the CO2 and NH3 emitted during MSWcomposting. Laboratory aerobic degradation studies of various solid organic wastes have been performed in the past.
*

Corresponding author. Tel.: +30 210 8624180. E-mail address: dkomilis@yahoo.com (D.P. Komilis).

Most laboratory studies have measured the reduction of the organic fraction during composting (Poincelot and Day, 1960; Inoko et al., 1979; Baca et al., 1992; Wang et al., 2003), whilesome studies have included a setup to capture and measure gases produced during composting. Michel et al. (1993) provided a laboratory setup to measure CO2 emissions during composting of mixtures of grass and leaves in sealed laboratory digesters and also measured the reduction of certain chemical groups (cellulose, hemicellulose, lignin) during the process. Nakasaki et al. (1994) measured thedegradation kinetics of grass clippings in laboratory reactors, providing a setup to capture and quantify the emitted CO2. In addition, measurements of cellulose, hemicellulose and lignin in the grass were performed. Nakasaki et al. (1998a) measured NH3 and other N gases emitted during dog food composting in thermophilic temperatures using a setup that also quantified CO2 emissions. The same setup wasalso used in Nakasaki et al. (1998b).

0956-053X/$ - see front matter Ó 2005 Elsevier Ltd. All rights reserved. doi:10.1016/j.wasman.2004.12.020

D.P. Komilis, R.K. Ham / Waste Management 26 (2006) 62–70

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Laboratory-scale digesters to quantify CO2 emissions during solid and agricultural waste composting experiments have been also described in Suler and Finstein (1977), Sikora et al....