Main Title |
Comparison of Photochemical Behavior of Various Humic Substances in Water: III. Spectroscopic Properties of Humic Substances. |
Author |
Zepp, Richard G. ;
Schlotzhauer, Patricia F. ;
|
CORP Author |
Environmental Research Lab., Athens, GA. |
Year Published |
1981 |
Report Number |
EPA-600/J-81-202; |
Stock Number |
PB81-232142 |
Additional Subjects |
Humic acids ;
Water analysis ;
Spectrochemical analysis ;
Photochemical reactions ;
Fluorescence ;
Comparison ;
Absorption spectra ;
Water pollution ;
Reprints ;
Water pollution detection
|
Holdings |
Library |
Call Number |
Additional Info |
Location |
Last Modified |
Checkout Status |
NTIS |
PB81-232142 |
Some EPA libraries have a fiche copy filed under the call number shown. |
|
07/26/2022 |
|
Collation |
10p |
Abstract |
Spectral absorption coefficients and fluorescence quantum efficiencies were determined for humic substances from a variety of sources. Specific absorption coefficients, K(h), for humic substances at wavelengths lambda from 300 to 500 nm can be closely described by the relation Ae supB(450-lambda), where A and B are constants. When the K(h) values are in units of liter (mg organic carbon) meter and wavelength lambda is in nanometers, mean values of A and B for aquatic humus in the 12 water bodies studied were 0.6 + or - 0.3 and 0.014 + or - 0.001, respectively. Spectral absorption coefficients of dissolved organic matter in blackwater rivers, of the 'yellow substance' in the sea, and of fulvic acids extracted from soils are very similar. Fluorescence quantum yields of humic substances were low and more variable than the absorption coefficients, ranging from 0.0005 to 0.012 with excitation at 350 nm (average of 0.0045 + or - 0.0038 for 6 waters). Fluorescence spectra for the humic substances were remarkably similar with maximum emission at 430 to 470 nm. Results of this study can be used to compute photolysis rates of pollutants as a function of depth in natural water bodies. |
Supplementary Notes |
Pub. in Chemosphere, v10 n5 p479-486 1981. See also pt. 2, PB81-192098. |
NTIS Title Notes |
Journal article. |
Title Annotations |
Reprint: Comparison of Photochemical Behavior of Various Humic Substances in Water: III. Spectroscopic Properties of Humic Substances. |
PUB Date Free Form |
16 Apr 81 |
Category Codes |
7D; 68D; 99A |
NTIS Prices |
PC A02/MF A01 |
Primary Description |
600/01 |
Document Type |
NT |
Cataloging Source |
NTIS/MT |
Control Number |
323802015 |
Origin |
NTIS |
Type |
CAT |