Biogeochemical evaluation of mechanisms controlling CaCO3(s) precipitation in landfill leachate-collection systems

A common failure mode for landfills is clogging of the leachate-collection system. The reduction in hydraulic conductivity associated with clogging causes a buildup of leachate head on the underlying liner, potentially increasing advective contaminant transport from the landfill and contaminating adjacent groundwater. In this paper, the biogeochemical model CCBATCH is used to link a primary cause of leachate collection system failure—CaCO3(s) precipitation—to anaerobic degradation of volatile fatty acids (VFAs) in column reactors used to study the clogging phenomena. One key to applying CCBATCH correctly was dividing the VFA conversion into two steps: conversion of propionate to acetate, carbonic acid, and methane; and acetate conversion to methane and carbonic acid. The primary driver for CaCO3(s) precipitation in the columns was acetate fermentation to CH4 and H2CO3, which increased the total carbonate concentration in the leachate and shifted the acid/base control to a weaker acid system, which caused ...

[1]  J. Vanbriesen,et al.  Modeling speciation effects on biodegradation in mixed metal/chelate systems , 1999, Biodegradation.

[2]  James J. Morgan,et al.  Numerical method for computing equilibriums in aqueous chemical systems , 1972 .

[3]  J. Vanbriesen,et al.  Mathematical modeling of precipitationand dissolution reactions in microbiological systems , 2004, Biodegradation.

[4]  R. K. Rowe,et al.  Field observations of clogging in a landfill leachate collection system , 1999 .

[5]  R. Kerry Rowe,et al.  Contaminant impact assessment and the contaminating lifespan of landfills , 1991 .

[6]  Bruce E. Rittmann,et al.  Leachate Chemistry: Its Implications for Clogging , 1996 .

[7]  Bruce E. Rittmann,et al.  Biofilm Growth and Mineral Precipitation in Synthetic Leachate Columns , 2001 .

[8]  W. Owen,et al.  Fundamentals of Anaerobic Digestion of Wastewater Sludges , 1986 .

[9]  Bruce E. Rittmann,et al.  Modeling biochemically driven mineral precipitation in anaerobic biofilms , 1999 .

[10]  W. Bae,et al.  A structured model of dual‐limitation kinetics , 2000, Biotechnology and bioengineering.

[11]  T H Christensen,et al.  Distribution of redox-sensitive groundwater quality parameters downgradient of a landfill (Grindsted, Denmark). , 1995, Environmental science & technology.

[12]  W. Bae,et al.  Responses of intracellular cofactors to single and dual substrate limitations , 2000, Biotechnology and bioengineering.

[13]  P. Mccarty,et al.  Environmental Biotechnology: Principles and Applications , 2000 .