Characterization of humic substances in landfill leachate and impact on the hydraulic conductivity of geosynthetic clay liners

A detailed characterization was performed on the humic substances present in landfill leachate derived from the older (10-year) and younger (6-month) municipal landfill cells at a site in Inchion, Korea. The characterization focused on the humic and fulvic acid components of the leachate, relying on information gleaned from the UV/visible spectroscopy, molecular weight distribution, and Fourier transform infrared spectroscopy. The effect of the leachates, and specific components of the leachates, on the hydraulic conductivity of a geosynthetic clay liner (GCL), was evaluated. The humic acid extracted from the older leachate was composed primarily of high molecular weight and aromatic compounds, which is typical for humic acids. However, the humic acid extracted from the younger leachate showed characteristics more similar with fulvic acids, indicating that the younger humic acid was at the initial stage of humification. The hydraulic conductivity of the GCLs to the humic and fulvic acids of the older and younger leachate was similar to those permeated with the distilled deionized water (DI). However, the hydraulic conductivity of the samples tested with the raw leachate was more than 200 times the DI value. This fact suggests that cations present in leachate, rather than humic substances, are the key factor in the increase of the permeability.

[1]  Thomas Højlund Christensen,et al.  CHARACTERIZATION OF THE DISSOLVED ORGANIC CARBON IN LANDFILL LEACHATE-POLLUTED GROUNDWATER , 1998 .

[2]  Hsin-Yu Shan,et al.  Effect of hydrating liquid on the hydraulic properties of geosynthetic clay liners , 2002 .

[3]  D. Greenland.  INTERACTIONS BETWEEN HUMIC AND FULVIC ACIDS AND CLAYS , 1971 .

[4]  Takeshi Katsumi.  Hydraulic conductivity of geosynthetic clay liners , 2010 .

[5]  David E. Daniel,et al.  Geosynthetic clay liners permeated with chemical solutions and leachates , 1997 .

[6]  Craig H. Benson,et al.  HYDRAULIC CONDUCTIVITY AND SWELL OF NONPREHYDRATED GEOSYNTHETIC CLAY LINERS PERMEATED WITH MULTISPECIES INORGANIC SOLUTIONS , 2004 .

[7]  W. Fuller,et al.  Humic Substances in Landfill Leachates: I. Humic Acid Extraction and Identification , 1982 .

[8]  J. Harmsen,et al.  Identification of organic compounds in leachate from a waste tip , 1983 .

[9]  R. Taylor.  Setting up 13C CP/MAS experiments , 2004 .

[10]  V. D'Orazio,et al.  Adsorption of chlordane onto humic acids from soils and pig slurry , 1999 .

[11]  E. O’Loughlin,et al.  Molecular weight, polydispersity, and spectroscopic properties of aquatic humic substances. , 1994, Environmental science & technology.

[12]  I. Kögel‐Knabner,et al.  Chemical heterogeneity of humic substances: characterization of size fractions obtained by hollow‐fibre ultrafiltration , 2000 .

[13]  A. Vassallo,et al.  Thermal stability of humic substances and their metal forms: an investigation using FTIR emission spectroscopy , 1997 .

[14]  G. R. Alther,et al.  The qualifications of bentonite as a soil sealant , 1987 .

[15]  Ki-Hoon Kang,et al.  Characterization of humic substances present in landfill leachates with different landfill ages and its implications. , 2002, Water research.

[16]  R M Quigley,et al.  Selected Factors Influencing GCL Hydraulic Conductivity , 1997 .

[17]  William R. Schubert.  Bentonite Matting in Composite Lining Systems , 1987 .

[18]  David Keith Todd,et al.  Ground Water Hydrology , 1959 .

[19]  R M Quigley,et al.  Comparison of Laboratory-Measured GCL Hydraulic Conductivity Based on Three Permeameter Types , 1997 .

[20]  David E. Daniel,et al.  Results of laboratory tests on a geotextile/bentonite liner material , 1991 .

[21]  M. Nanny,et al.  Characterization and comparison of hydrophobic neutral and hydrophobic acid dissolved organic carbon isolated from three municipal landfill leachates. , 2002, Water research.

[22]  T. Miano,et al.  Humic-like Substances in Organic Amendments and Effects on Native Soil Humic Substances , 1996 .

[23]  M. Bekbolet,et al.  Implementation of spectroscopic parameters for practical monitoring of natural organic matter , 2005 .

[24]  E. Tombácz,et al.  Surface charge heterogeneity and aggregation of clay lamellae in aqueous suspensions , 2004 .

[25]  Charles D. Shackelford,et al.  Waste-Soil Interactions that Alter Hydraulic Conductivity , 1994 .

[26]  F. J. Stevenson.  HUmus Chemistry Genesis, Composition, Reactions , 1982 .

[27]  H. Fu,et al.  Complexes of fulvic acid on the surface of hematite, goethite, and akaganeite: FTIR observation. , 2006, Chemosphere.

[28]  Craig H. Benson,et al.  Long-term hydraulic conductivity of a geosynthetic clay liner permeated with inorganic salt solutions , 2005 .

[29]  David E. Daniel,et al.  Calcium and sodium bentonite for hydraulic containment applications , 1997 .

[30]  M. Shibata,et al.  Molecular Weight Characterization of Humic Substances by MALDI-TOF-MS , 2004 .

[31]  E. Thurman,et al.  Preparative isolation of aquatic humic substances. , 1981, Environmental science & technology.

[32]  A. Piccolo,et al.  Role of hydrophobic components of soil organic matter in soil aggregate stability , 1999 .

[33]  Craig H. Benson,et al.  HYDRAULIC CONDUCTIVITY AND SWELLING OF NONPREHYDRATED GCLS PERMEATED WITH SINGLE-SPECIES SALT SOLUTIONS , 2001 .