Characterization of humic and fulvic acids extracted from landfill by elemental composition, 13C CP/MAS NMR and TMAH-Py-GC/MS.
Humic acid (HA) and fulvic acid (FA) extracted from landfills at different landfill ages were characterized by elemental composition, (13)C CP/MAS NMR, and TMAH-Py-GC/MS. 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 analytical results of (13)C CP/MAS NMR suggested that there were more oxygenated aliphatic carbons and fewer aromatic carbons in FA than in HA. The Py-GC/MS products showed that the HA and FA extracted from the refuse in the landfill were mainly composed of various lignin-derived compounds. Oxidized aromatic acid derivatives originated from the oxidation of side-chains of lignin-like compounds, and this process played a significant role in the process of HA and FA formation in the landfill. All of the results demonstrated that the degree of humification increased with landfill age.
Xiaoli
Chai
C
The State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Shanghai 200092, China. xlchai@mail.tongji.edu.cn
Shimaoka
Takayuki
T
Qiang
Guo
G
Youcai
Zhao
Z
D001578:Benzopyrans / Q000737:chemistry*; D002247:Carbon Isotopes; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods; D006812:Humic Substances / Q000032:analysis*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods; D012037:Refuse Disposal / Q000379:methods*
D001578:Benzopyrans; D002247:Carbon Isotopes; D006812:Humic Substances; C005023:fulvic acid