The purpose of this study is to illustrate the characteristics of soil organic matter (SOM) and partition coefficient (KDOC). Humic substances (HS) from eight soils of varying properties were extracted by two different methods. The dissolved organic carbon (DOC) concentration was stabilized in 22hrs. The ratio of UV absorbance at 465nm and 665nm (E4/E6 ratio) for HS were similar pattern for 8 soils. The extraction with increasing pH increased dissolution of SOM. The ratio of organic carbon (OC) associated with HA and FA (the HA:FA ratio) was varied widely in accordance with the soils and was highly correlated to OC content(%) of the soils. In modeling metal speciation in soils and soil solutions, assumptions that all DOC in soil solution is associated with FA and that HA:FA ratio in SOM is constant have been made. The results of this study indicate that the validity of these assumptions is questionable. By sequential pH extraction, the KDOC showed in a linear correlation with pH.

• Sun Jae You(Department of Civil & Environmental Engineering, Kunsan National University)
• Jong Gu Kim(Department of Civil & Environmental Engineering, Kunsan National University) Corresponding Author
• Eun Il Cho(Major of Civil & Environmental Engineering, Cheju National University)