A dynamic mathematical model for sequential leach bed anaerobic digestion of organic fraction of municipal solid waste


Autoria(s): Nopharatana, Annop; Pullammanappallil, Pratap C.; Clarke, William P.
Data(s)

01/01/2003

Resumo

A mathematical model that describes the operation of a sequential leach bed process for anaerobic digestion of organic fraction of municipal solid waste (MSW) is developed and validated. This model assumes that ultimate mineralisation of the organic component of the waste occurs in three steps, namely solubilisation of particulate matter, fermentation to volatile organic acids (modelled as acetic acid) along with liberation of carbon dioxide and hydrogen, and methanogenesis from acetate and hydrogen. The model incorporates the ionic equilibrium equations arising due to dissolution of carbon dioxide, generation of alkalinity from breakdown of solids and dissociation of acetic acid. Rather than a charge balance, a mass balance on the hydronium and hydroxide ions is used to calculate pH. The flow of liquid through the bed is modelled as occurring through two zones-a permeable zone with high flushing rates and the other more stagnant. Some of the kinetic parameters for the biological processes were obtained from batch MSW digestion experiments. The parameters for flow model were obtained from residence time distribution studies conducted using tritium as a tracer. The model was validated using data from leach bed digestion experiments in which a leachate volume equal to 10% of the fresh waste bed volume was sequenced. The model was then tested, without altering any kinetic or flow parameters, by varying volume of leachate that is sequenced between the beds. Simulations for sequencing/recirculating 5 and 30% of the bed volume are presented and compared with experimental results. (C) 2002 Elsevier Science B.V. All rights reserved.

Identificador

http://espace.library.uq.edu.au/view/UQ:66880

Idioma(s)

eng

Publicador

lsevier Science SA

Palavras-Chave #Biotechnology & Applied Microbiology #Engineering, Chemical #Anaerobic Processes #Biogas #Municipal Solid Waste #Waste Treatment #Dynamic Modelling And Simulation #Batch Processing #Hydrolysis Kinetics #Degradation #Reactor #Matter #Acids #Msw #C1 #290699 Chemical Engineering not elsewhere classified #270307 Microbial Ecology #291104 Environmental Technologies #770502 Land and water management #660299 Renewable energy not elsewhere classified (e.g. geothermal) #710201 Waste management
Tipo

Journal Article