title: Anthropogenic signature of sediment organic matter probed by UV-Visible and fluorescence spectroscopy and the association with heavy metal enrichment.
abstract: Sediment organic matter (SOM) was extracted in an alkaline solution from 43 stream sediments in order to explore the anthropogenic signatures. The SOM spectroscopic characteristics including excitation-emission matrix (EEM)-parallel factor analysis (PARAFAC) were compared for five sampling site groups classified by the anthropogenic variables of land use, population density, the loadings of organics and nutrients, and metal enrichment. The conventional spectroscopic characteristics including specific UV absorbance, absorbance ratio, and humification index did not properly discriminate among the different cluster groups except in the case of metal enrichment. Of the four decomposed PARAFAC components, humic-like and tryptophan-like fluorescence responded negatively and positively, respectively, to increasing degrees of the anthropogenic variables except for land use. The anthropogenic enrichment of heavy metals was positively associated with the abundance of tryptophan-like component. In contrast, humic-like component, known to be mostly responsible for metal binding, exhibited a decreasing trend corresponding with metal enrichment. These conflicting trends can be attributed to the overwhelmed effects of the coupled discharges of heavy metals and organic pollutants into sediments. Our study suggests that the PARAFAC components can be used as functional signatures to probe the anthropogenic influences on sediments.
authors.affiliation: Department of Environment and Energy, Sejong University, Seoul 143-747, South Korea.
authors.forename: Wei
authors.initials: W
authors.lastname: He
authors.affiliation: NEO Environmental Business Corporation, Bucheon 420-806, South Korea.
authors.forename: Jong-Hyun
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Environment and Energy, Sejong University, Seoul 143-747, South Korea. Electronic address: jinhur@sejong.ac.kr.
authors.forename: Jin
authors.initials: J
authors.lastname: Hur
mesh_terms: D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D005163:Factor Analysis, Statistical; D019015:Geologic Sediments / Q000737:chemistry*; D006812:Humic Substances / Q000032:analysis*; D019216:Metals, Heavy / Q000032:analysis*; D056910:Republic of Korea; D045483:Rivers / Q000737:chemistry*; D013050:Spectrometry, Fluorescence / Q000379:methods; D013056:Spectrophotometry, Ultraviolet / Q000379:methods; D014874:Water Pollutants, Chemical / Q000032:analysis*
chemical_list: D006812:Humic Substances; D019216:Metals, Heavy; D014874:Water Pollutants, Chemical
keywords: Alkaline extractable organic matter; Heavy metals; Human activities; Parallel factor analysis; Sediment organic matter