HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Full Text Free Full Text (PDF) Free Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Hellebrand, H.J. Articles by Schade, G.W. Search for Related Content PubMed Articles by Hellebrand, H.J. Articles by Schade, G.W. Agricola Articles by Hellebrand, H.J. Articles by Schade, G.W. Related Collections Biogeochemical Processes Landscape-Atmosphere Interactions Air Pollution

Carbon Monoxide from Composting due to Thermal Oxidation of Biomass

^a Leibniz Institute for Agricultural Engineering Potsdam-Bornim (ATB), Max-Eyth-Allee 100, D-14469 Potsdam, Germany
^b Dep. of Atmospheric Sciences, Texas A&M Univ., 3150 TAMU, College Station, TX 77843-3150, USA

View larger version (42K): [in this window] [in a new window]   Fig. 1. Fourier-transform infrared spectroscopy (FT-IR) spectrum of ambient air between 600 and 4000 cm–1 (reverse scale increases with wavelength; measured with 20 m long path gas cell). The IR lines of the strong absorbers CO2 and H2O stand out. Sections with absorption lines of environmentally relevant trace gases are marked by circled numbers: 1: CO; 2: NH3; 3: N2O; 4: CH4.

View larger version (32K): [in this window] [in a new window]   Fig. 2. Example section of Fourier-transform infrared spectroscopy (FT-IR) absorption spectrum of an air sample during laboratory scale composting of hay (mixed herbage from landscape conservation with a moisture content (w.b.) of 0.7 x 10–3 m3 kg–1) amended with calcium ammonium nitrate (resolution 0.2 cm–1, temperature 35°C, aeration rate 17 cm3 min–1 kg–1 substrate). Circled numbers indicate sections analyzed in detail: 1: Superposition of CO2, N2O, and CO; 2: Mainly CO lines; 3: Mainly CO2 lines; 4: Minimally disturbed CO lines.

View larger version (25K): [in this window] [in a new window]   Fig. 3. Schematic of the compost heap with inserted polyethylene tubes, and the variation of CO concentrations measured in samples extracted through them. Arrows indicate dates of turning the compost.

View larger version (29K): [in this window] [in a new window]   Fig. 4. Temperature influence on CO concentration trends in the substrate container containing degrading herbage mixture from landscape conservation with a moisture content (w.b.) of 0.7 x 10–3 m3 kg–1. The ventilation rate was 25 cm3 min–1 kg–1 substrate. 35°C was measured twice.

View larger version (27K): [in this window] [in a new window]   Fig. 5. Temperature influence on CO2 concentration trends in the substrate container containing degrading herbage mixture from landscape conservation with a moisture content (w.b.) of 0.7 x 10–3 m3 kg–1. The ventilation rate was 25 cm3 min–1 kg–1 substrate. 35°C was measured twice.

View larger version (15K): [in this window] [in a new window]   Fig. 6. Carbon monoxide and CO2 concentration variation in air exiting the substrate chamber containing degrading mixed herbage from landscape conservation (without sterilization, moisture content (w.b.) of 0.7x10–3 m3 kg–1, temperature 50°C, ventilation rate 25 cm3 min–1 kg–1 substrate).

View larger version (14K): [in this window] [in a new window]   Fig. 7. Carbon monoxide and CO2 concentration variation in air exiting the substrate chamber containing degrading mixed herbage from landscape conservation (sample sterilized for 3 h at 136°C, moisture content (w.b.) of 0.7x10–3 m3 kg–1, temperature 50°C, ventilation rate 25 cm3 min–1 kg–1 substrate).

View larger version (18K): [in this window] [in a new window]   Fig. 8. Arrhenius plot of CO and CO2 production rates (sterilized wet substrate, ventilation rate 25 cm3 min–1 kg–1 substrate) between 278 and 338 K. The exponential approximation functions and determination coefficients are given in the figure. The activation energy results from multiplication of the exponential factor with the gas constant.