Radiocarbon measurements of dissolved organic carbon in sewage-treatment-plant effluent and domestic sewage

摘要

In an attempt to better characterize dissolved organic carbon (DOC) in several specific sources to Lake Kasumigaura, such as sewage-treatment-plant effluent (STPE), domestic sewage (DS) and forest stream (FS), we analyzed radiocarbon (~(14)C) and stable carbon isotopic compositions (~(13)C) of the DOCs. The measurements of ~(14)C for DOC were performed by an accelerator mass spectrometer (AMS) at the National Institute for Environmental Studies (NIES-TERRA) in Japan. The Δ~(14)C and δ~(13)C values of the DOCs in several sources to Lake Kasumigaura, have low carbon isotopic values, ranging from -470‰ to -79‰ and from -27.9‰ to -24.2‰, respectively. These carbon isotopic values are substantially different from those of Lake Kasumigaura. These results imply different origins for the DOC in Lake Kasumigaura. The ~(14)C and ~(13)C analyses of DOC led to a useful classification for DOCs in Lake Kasumigaura, Japan.