title: Characterization and comparison of hydrophobic neutral and hydrophobic acid dissolved organic carbon isolated from three municipal landfill leachates.
abstract: The acid-precipitated (AP) and acid-soluble (AS) fractions of the combined hydrophobic neutral and hydrophobic acid dissolved organic carbon (DOC) were isolated from leachate collected from three municipal landfills of different age and redox conditions. The AP and the AS combined hydrophobic neutral and hydrophobic acid DOC comprised 6-15% and 51-66%, respectively, of the leachate nonpurgable organic carbon. Elemental analysis, infra-red spectroscopy, 13C CP-MAS nuclear magnetic resonance spectroscopy and dipolar dephasing experiments, and thermochemolysis gas chromatography/mass spectrometry results showed that the AP and AS fractions of hydrophobic neutral and hydrophobic acid DOC are highly aliphatic, with linear and branching moieties, and less oxidized than most terrestrial and aquatic humic substances. Very little, if any, polysaccharide or cellulose, lignin, or cutin components comprise these fractions. It is hypothesized that a majority of the organic carbon in these fractions originates highly branched, cyclic aliphatic organic compounds.
authors: School of Civil Engineering and Environmental Science, University of Oklahoma, Norman 73019, USA. nanny@ou.edu
authors: Mark A
authors: MA
authors: Nanny
authors: Nopawan
authors: N
authors: Ratasuk
mesh_terms: D000143:Acids / Q000737:chemistry*; D002244:Carbon / Q000032:analysis* / Q000737:chemistry*; D004785:Environmental Pollutants / Q000032:analysis*; D008401:Gas Chromatography-Mass Spectrometry; D006863:Hydrogen-Ion Concentration; D057927:Hydrophobic and Hydrophilic Interactions; D009682:Magnetic Resonance Spectroscopy; D009930:Organic Chemicals / Q000032:analysis* / Q000737:chemistry*; D012037:Refuse Disposal; D012996:Solutions / Q000737:chemistry; D013055:Spectrophotometry, Infrared
chemical_list: D000143:Acids; D004785:Environmental Pollutants; D009930:Organic Chemicals; D012996:Solutions; D002244:Carbon