Effect of physical forms of soil organic matter on phenanthrene sorption

• Published in: Chemosphere (Oxford) Vol. 68; no. 7; pp. 1262 - 1269
• Main Authors: Pan, Bo, Xing, Baoshan, Tao, Shu, Liu, Wenxin, Lin, Xiumei, Xiao, Yang, Dai, Hancheng, Zhang, Xianming, Zhang, Yanxv, Yuan, Huishi
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01-07-2007; Elsevier
• Subjects: Adsorption; Applied sciences; Biological and physicochemical properties of pollutants. Interaction in the soil; Earth sciences; Earth, ocean, space; Engineering and environment geology. Geothermics; Exact sciences and technology; Humic acid; humic acids; Humic Substances; Hydrocarbons, Aromatic - chemistry; hydrogen peroxide; Hydrogen Peroxide - chemistry; Minerals - chemistry; Organo-mineral complex; PAHs; Phenanthrene; Phenanthrenes - chemistry; Physical conformation; physical properties; polar compounds; Pollution; Pollution, environment geology; shape; Soil - analysis; Soil and sediments pollution; Soil organic matter; soil pollution; sorption; sorption coefficient; Soil organic matter; PAHs; Phenanthrene; Physical conformation; Organo-mineral complex; Humic acid; PAHs: Organo-mineral complex; Organic matter; Hydrocarbon; Property composition relationship; Pollutant behavior; Adsorption capacity; Property of soil; Hydrophobic compound; Environmental factor; Polycyclic aromatic compound; Soil pollution; Sorption; Property structure relationship
• ISSN: 0045-6535; 1879-1298
• DOI: 10.1016/j.chemosphere.2007.01.054

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
2O
2 to remove organic matter, and humic acid was coated on H
2O
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
2O
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.