Details

Autor(en) / Beteiligte

• Song, Jianzhong
• Peng, Ping'an
• Huang, Weilin

Titel

Black Carbon and Kerogen in Soils and Sediments. 1. Quantification and Characterization

Ist Teil von

• Environmental science & technology, 2002-09, Vol.36 (18), p.3960-3967

Ort / Verlag

Washington, DC: American Chemical Society

Erscheinungsjahr

2002

Quelle

MEDLINE

Beschreibungen/Notizen

• A comprehensive wet chemical procedure was developed by combining acid demineralization, base extraction, and dichromate oxidation for fractionation and quantitative isolation of soil/sediment organic matter (SOM) into four fractions:  (1) humic acids + kerogen + BC (HKB); (2) kerogen + BC (KB); (3) humic acid (HA); and (4) BC. The soil/sediment samples tested were collected from the suburban areas of Guangzhou, a rapidly developing city of China. The results show that BC and kerogen constitute 57.8−80.6% of the total organic carbon (TOC) and that the relative content of BC ranges from 18.3% to 41.0% of the TOC, indicating that both BC and kerogen are major organic components in soils and sediments from this industrialized region. Systematic characterization of the isolated SOMs shows that both BC and kerogen have sizes ranging from a few microns to above 100 μm, relatively low O/C and H/C atomic ratios, and low contents of oxygen-containing functional groups. The isolated BC has unique fusinite and semifusinite macerals, highly porous nature, and structures indicative of its possible origins. The study indicates that SOM is highly heterogeneous and that humin, the nonextractable humus fraction, consists mainly of kerogen and BC materials in the tested soil/sediment samples. The presence of these materials in soils and sediments may have significant impacts on pollutant mass transfer and transformation processes such as desorption and bioavailability of less polar organic chemicals in surface aquatic and groundwater environments.