Evolution of clog formation with time in columns permeated with synthetic landfill leachate.

Laboratory column tests conducted to gain insight regarding the biological and chemical clogging mechanisms in a porous medium are presented. To seed the porous medium with landfill bacteria, a mixture of Keele Valley Landfill and synthetic leachate permeated through the column under anaerobic conditions for the first 9 days of operation. After this, 100% synthetic leachate was used. The synthetic leachate approximated Keele Valley Landfill leachate in chemical composition but contained negligible suspended solids and bacteria compared with real leachate. The removal of volatile fatty acids (VFAs), primarily acetate, in leachate as it passed through the medium was highly correlated with the precipitation of calcium carbonate (CaCO(3(s))) from solution. The columns experienced a decrease in drainable porosity from an initial value of about 0.38 to less than 0.1 after steady state chemical oxygen demand (COD) removal, resulting in a five-order magnitude decrease in hydraulic conductivity. The decrease in drainable porosity prior to steady state COD removal was primarily due to the growth of a biofilm on the medium surface. After steady state COD removal, calcium precipitation was at least equally responsible for the decrease in drainable porosity as biofilm growth. Clog composition analyses showed that CaCO(3(s)) was the dominant clog constituent and that 99% of the carbonate in the clog material was bound to calcium.

[1]  Bruce E. Rittmann,et al.  The significance of biofilms in porous media , 1993 .

[2]  M. P. Bryant,et al.  Propionate-Degrading Bacterium, Syntrophobacter wolinii sp. nov. gen. nov., from Methanogenic Ecosystems , 1980, Applied and environmental microbiology.

[3]  R. Rowe,et al.  Intrinsic degradation of volatile fatty acids in laboratory-compacted clayey soil. , 2002, Journal of contaminant hydrology.

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

[5]  W. Powrie,et al.  A laboratory investigation of anaerobic microbial clogging in granular landfill drainage media , 1998 .

[6]  R. Koerner,et al.  Landfill leachate clogging of geotextile (and soil) filters , 1991 .

[7]  Armstrong,et al.  Mass loading and the rate of clogging due to municipal solid waste leachate , 2000 .

[8]  R. Kerry Rowe,et al.  Particle Size and Clogging of Granular Media Permeated with Leachate , 2000 .

[9]  R. Maliva,et al.  Unusual calcite stromatolites and pisoids from a landfill leachate collection system , 2000 .

[10]  B. Rittmann,et al.  The nonsteady-state-biofilm process for advanced organics removal , 1984 .

[11]  雅史 嘉門,et al.  Geosynthetics and the Minimization of Contaminated Migration through Barrier Systems beneath Solid Waste , 1998 .

[12]  C. M. Sangha,et al.  Direct wet surface imaging of an anaerobic biofilm by environmental scanning electron microscopy: application to landfill clay liner barriers. , 2006, Scanning.

[13]  Morton A. Barlaz,et al.  Microbiology of Solid Waste , 1996 .

[14]  B. Rittman,et al.  The effect of shear stress on biofilm loss rate. , 1982, Biotechnology and bioengineering.

[15]  W. Powrie,et al.  Removal of volatile acids from synthetic landfill leachate by anaerobic biofilms on drainage aggregates: a laboratory study , 1999 .

[16]  R. Koerner,et al.  Long-term temperature monitoring of geomembranes at dry and wet landfills , 2006 .

[17]  D. Manning.  Carbonates and oxalates in sediments and landfill: monitors of death and decay in natural and artificial systems , 2000, Journal of the Geological Society.

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

[19]  R. Rowe,et al.  Predicting Biogeochemical Calcium Precipitation in Landfill Leachate Collection Systems , 2003, Biodegradation.

[20]  K. Jones,et al.  Methane generation and microbial activity in a domestic refuse landfill site , 1983, European journal of applied microbiology and biotechnology.

[21]  R. Rowe,et al.  Biologically induced clogging of a granular medium permeated with synthetic leachate , 2002 .

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

[23]  Tamás Meggyes,et al.  Advanced Landfill Liner Systems , 1997 .

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

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