토양 휴민(Humin)의 분자구조 특성과 Phenanthrene 흡착상수와의 상관관계에 대한 연구

In this study, sorption coefficients (logKOC, n) for the binding of phenanthrene (PHE) to soil humins, insoluble fractionof soil humc substances (HS), were determined and relationship between the sorption coefficients and structural characteristics of thesoil humins were investigated. The soil humins used in the present study were isolated from 7 different soils including 5 domesticsoils, an IHSS standard and a peat soil, and characterized by elemental analysis and CPMAS 13C NMR method. 13C NMR spectralfeatures indicate that the soil humins are mainly made up of aliphatic carbons (57.1~72.3% in total carbon) with high alkyl-Cmoiety, and the alkyl-C contents (CAl-H,C, %) was in order of granite soil Hu (26~42%) > volcanic ash soil, HL Hu (23.9%) > PeatHu (14.0%). The results of correlation study show that a positive relationship (r2 = 0.77, p < 0.05) between organic carbon normalized-sorption coefficients (KOC, mL/g) and alkyl-C contents(CAl-H,C, %), while negative relationship (r2 = (-)0.74, p < 0.05)between Freundlich sorption parameter (n) and H,C-substituted aromatic carbon contents (CAr-H,C, %). The magnitude of KOC valuesare also negatively well correlated with polarity index (e.g., PI, N + O)/C) (r2 = (-)0.74, p < 0.1). These results suggest that thebinding capacity (e.g., KOC) for PHE is increased in soil humin molecules having high contents of alkyl-C or lower polarity, andnonlinear sorption for PHE increased as the H,C-substituted aromatic carbon contents (CAr-H,C, %) in the soil humins increased.
The PHE sorption characteristics on soil humins are discussed based on the dual reactive mode of sorption model.