Modelling MSW decomposition under landfill conditions considering hydrolytic and methanogenic inhibition
- 299 Downloads
A landfill typically progresses through a series of microbial degradation phases, in which hydrolysis, production and consumption of fermentation products, such as fatty acids, and methane formation play important roles. For ultimate degradation of the waste, stable methanogenic conditions have to be attained, and maintained for sufficient time. Using experimental data from 100-L landfill simulation reactors containing municipal solid waste from a residential area, a distributed model, which accounts for vertical water flow, was developed. As a first step, the waste was divided into two fractions: readily degradable and recalcitrant waste. Secondly, the general hydrolysis of the recalcitrant waste was accounted for by including a specific, well-defined chemical substance in the model that generally occurs in Municipal Solid Waste (MSW) and is hydrolysed before its further degradation to methane. For this purpose we chose diethyl phthalate and its hydrolysis product monoethyl phthalate, for which leachate data are available from the reactors. The model indicated that inhibition of the hydrolytic and methanogenic processes occurred during␣the acidogenic phase and that it could be overcome either by improving the chemical environment or by the complete oxidation of the inhibiting, i.e. the easily degraded, fraction of the waste. The generality of the model was confirmed by the patterns of the phthalate di- and monoester transformations obtained. The validity of the model was further confirmed using experimental data from parallel reactors, which were subjected to either leachate exchange with an already methanogenic reactor or to initial aeration to force the reactor into stable methanogenic conditions.
Key wordsaeration anaerobic digestion distributed model diethyl phthalate inhibition methanogenesis
Unable to display preview. Download preview PDF.
The reviewers are gratefully acknowledged for their valuable comments on the text. This work was supported in part by the INCO-Copernicus-2 Program (grant ICA2-CT-2001–10001). The generous support of Vasily A. Vavilin and Susanne Jonsson by the Swedish Foundation for International Cooperation in Research and Higher Education (grant nos. KG2003–4513 and KU2003–4056) is greatly appreciated.
- Batstone DJ., Keller J, Angelidaki I, Kalyuzhnyi SV, Pavlostathis SG, Rozzi A, Sanders WTM, Siegrist H, Vavilin VA 2002. The IWA anaerobic digestion model No.1 (ADM1) Wat. Sci. Technol. 45(10):65–73Google Scholar
- Christensen TH, Kjeldsen P. (1989) Basic biochemical processes in landfills In: Christensen TH (eds) Sanitary Landfilling: Process, Technology and Environmental Impact. Academic Press, London pp 29–49Google Scholar
- Chynoweth DP, Pullammanappallil P (1996) Anaerobic digestion of municipal solid wastes In: Palmisano AC, Barlaz MA (eds) Microbiology of Solid Waste.CRS Press, Boca Raton, FL.71–13Google Scholar
- Ejlertsson J, Houwen FP, Svensson BH 1996a. Anaerobic degradation of diethyl phthalate and phthalic acid during incubation of municipal solid waste from a biogas digester Swedish J. Agric. Res. 26: 53–59Google Scholar
- Lagerkvist A & Chen H (1992) Control of anaerobic degradation of MSW by enzyme addition. Proc. Int. Symp on Anaerobic Digestion of Solid Waste, IAWPRC, Venice, Italy. (pp 75–84)Google Scholar
- Lagerkvist A (2003) (Ed) Landfill Technology Technical Report 2003:15, Luleå University of Technology. Dept. of Env. Engineer, Div. Waste Science and Technology, pp 10–32Google Scholar
- Pohland FG, Cross WH & King LW (1992) Codisposal of disposable diapers with shredded municipal refuse in simulated landfills. Proc. Int. Symp on Anaerobic Digestion of Solid Waste, IAWPRC, Venice, Italy. pp 269–283Google Scholar
- Saeger VW, Tucker ES, (1973) Pthalate esters undergo ready biodegradation Plastics Engineering 29:46–49Google Scholar
- Stegmann R (1981) Beschreibung eines Verfahrens zur Untersuchung anaerober Umsetzungsprozesse von Festen Abfallstoffen im Labormab-stab. Mull und Abfall 2 Google Scholar
- ten Brummeler E, Horbach HCJM, Koster IW (1991) Dry anaerobic batch digestion of the organic fraction of municipal solid waste J.Chem. Tech. Biotechnol. 50: 191–209Google Scholar
- Vavilin VA (2003) Landfill as an excitable media. Conf. Proc: Workshop on Sustainable Landfill Management (pp 51–60) 3–5 Dec 2003, Chennai, India. Allied Publisher Pvt Limited, New DelhiGoogle Scholar