title: Effect of physical forms of soil organic matter on phenanthrene sorption.
abstract: The sorption coefficient, K(OC), of phenanthrene (PHE) has been reported to vary with different types of organic matter, leading to uncertainties in predicting the environmental behavior of PHE. Among the studies that relate organic matter properties to their sorption characteristics, physical conformation of organic matter is often neglected. In this work, organic matter samples of different physical forms were examined for their sorption characteristics. Dissolved humic acids (DHA) showed significantly higher K(OC) than the corresponding solid humic acids (SHA) from which the DHAs were made. The K(OC) of DHAs was found to be related to polarity, whereas K(OC) of SHAs increased with aliphatic carbon content. Soil particles were treated with H(2)O(2) to remove organic matter, and humic acid was coated on H(2)O(2)-treated soil particles to make organo-mineral complexes at pH 4, 7 and 10. Although the nonlinear sorption was apparent for SHAs and H(2)O(2)-treated soil particles, the organo-mineral complexes formed using these two components at pH 4, 7 and 10 exhibited relatively linear sorption at organic carbon content, f(OC)>0.5%. These results indicate that organic matter of the same composition may have different sorption properties due to different physical forms (or conformations). Nonlinear sorption for the complexes formed at pH 4 with lower f(OC) (<0.5%) was also discussed.
authors.affiliation: Laboratory for Earth Surface Processes, College of Environmental Sciences, Peking University, Beijing, 100871, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Pan
authors.forename: Baoshan
authors.initials: B
authors.lastname: Xing
authors.forename: Shu
authors.initials: S
authors.lastname: Tao
authors.forename: Wenxin
authors.initials: W
authors.lastname: Liu
authors.forename: Xiumei
authors.initials: X
authors.lastname: Lin
authors.forename: Yang
authors.initials: Y
authors.lastname: Xiao
authors.forename: Hancheng
authors.initials: H
authors.lastname: Dai
authors.forename: Xianming
authors.initials: X
authors.lastname: Zhang
authors.forename: Yanxv
authors.initials: Y
authors.lastname: Zhang
authors.forename: Huishi
authors.initials: H
authors.lastname: Yuan
mesh_terms: D000327:Adsorption; D006812:Humic Substances; D006841:Hydrocarbons, Aromatic / Q000737:chemistry; D006861:Hydrogen Peroxide / Q000737:chemistry; D008903:Minerals / Q000737:chemistry; D010616:Phenanthrenes / Q000737:chemistry*; D012987:Soil / Q000032:analysis*
chemical_list: D006812:Humic Substances; D006841:Hydrocarbons, Aromatic; D008903:Minerals; D010616:Phenanthrenes; D012987:Soil; C031181:phenanthrene; D006861:Hydrogen Peroxide