title: Spectroscopic studies of the progress of humification processes in humic substances extracted from refuse in a landfill.
abstract: Humic acids (HA) and fulvic acids (FA) extracted from refuse in a landfill at different landfill ages were characterized by elemental composition, GPC, FTIR, and (13)C CP/MAS NMR. The elemental composition analysis revealed high O/C and low H/C ratios in the FA, indicating a high proportion of O-alkyl and carboxylic acids in the FA. The M(w) and M(n) values and M(w)/M(n) ratios indicated that the HA had a higher molecular weight and were more homogeneous with respect to molecular weight. FTIR spectra showed that the FA had relatively more intense bands assigned to aliphatic structures and were abundant in oxygen-containing function groups. The analytical results of (13)C CP/MAS NMR suggested that there were more oxygenated aliphatic carbons and fewer aromatic carbons in the FA than in the HA. All the results demonstrated that the degree of humification increased with landfill age.
authors.affiliation: The State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200 092, China. xlchai@mail.tongji.edu.cn
authors.forename: Xiaoli
authors.initials: X
authors.lastname: Chai
authors.forename: Takayuki
authors.initials: T
authors.lastname: Shimaoka
authors.forename: Xiaoyan
authors.initials: X
authors.lastname: Cao
authors.forename: Qiang
authors.initials: Q
authors.lastname: Guo
authors.forename: Youcai
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D001578:Benzopyrans / Q000032:analysis*; D002850:Chromatography, Gel; D006812:Humic Substances / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy; D008970:Molecular Weight; D012037:Refuse Disposal; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D001578:Benzopyrans; D006812:Humic Substances; D014874:Water Pollutants, Chemical; C005023:fulvic acid