The effect of probe choice and solution conditions on the apparent photoreactivity of dissolved organic matter

2017 ◽  
Vol 19 (8) ◽  
pp. 1040-1050 ◽  
Author(s):  
Andrew C. Maizel ◽  
Christina K. Remucal
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Natural Waters ◽  
Photochemical Production

Probe choice, pH, and [DOC] impact the apparent photochemical production of triplet dissolved organic matter in diverse natural waters.

Assessing the Source of the Photochemical Formation of Hydroxylating Species from Dissolved Organic Matter Using Model Sensitizers

2021 ◽  
Author(s):  
Kylie Couch ◽  
Frank Leresche ◽  
Claire Farmer ◽  
Garrett McKay ◽  
Fernando Rosario
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Singlet Oxygen ◽  
Natural Waters ◽  
Photochemical Formation ◽  
Photochemical Production

Dissolved organic matter (DOM) is ubiquitous in natural waters and can facilitate the chemi-cal transformation of many contaminants through the photochemical production of reactive inter-mediates, such as singlet oxygen (1O2),...

scholarly journals Photochemical effects on the interaction of enzymes and dissolved organic matter in natural waters

2003 ◽  
Vol 48 (5) ◽  
pp. 1818-1824 ◽  
Author(s):  
Norman M. Scully ◽  
Lars J. Tranvik ◽  
William J. Cooper
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Natural Waters

scholarly journals Optical Properties of Dissolved Organic Matter in Finnish and Estonian Lakes

2003 ◽  
Vol 34 (4) ◽  
pp. 361-386 ◽  
Author(s):  
L. Sipelgas ◽  
H. Arst ◽  
K. Kallio ◽  
A. Erm ◽  
P. Oja ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Natural Waters ◽  
Mean Value ◽  
Published Data ◽  
Optical Parameters ◽  
Exponential Approximation ◽  
Absorption Coefficients ◽  
Specific Absorption ◽  
The Mean

The main objective of the present study is to test various methods for describing the absorption spectra of coloured dissolved organic matter (CDOM) and to determine the numerical values of some optical parameters of CDOM in lakes with diverse water quality. First, the parameters of an exponential model in different spectral intervals were determined. In addition, the suitability of some other models for the approximation of CDOM spectra was estimated. Specific absorption coefficients of CDOM were calculated from the absorption coefficients and dissolved organic carbon (DOC) concentrations. The experimental initial data were differences between spectral attenuation coefficients of filtered and distilled water. Two datasets were used: 1) for 13 Estonian and 7 Finnish lakes (altogether 404 spectra between 350 and 700 nm) measured by the Estonian Marine Institute (EMI); 2) for 10 Finnish lakes (73 spectra) measured by the Finnish Environment Institute (FEI). The spectra of CDOM absorption coefficients (aCDOM) were calculated from experimental data taking into account the correction due to scattering properties of colloids in the filtered water. The total content of CDOM in natural waters of Estonian and Finnish lakes was expressed by means of aCDOM at the wavelength of 380 nm. It varied significantly, from 0.71 to 19.5 m−1, the mean value (of all the investigated lakes) being around 6.6 m−1. Slopes of the exponential approximation varied widely, from 0.006 to 0.03 nm−1. Averaged over all lakes values of slope for the interval 380-500 nm obtained from the EMI dataset are close to those obtained from the FEI dataset: from 0.014 nm−1 (without correction) to 0.016-0.017 nm-1 (with different types of correction). These results are in good correspondence with most published data. Attempts to describe the spectra in the region of 350-700 nm by means of hyperexponential functions (∽ exp(-αλη)) show that: (1) η < 1 (in the case of traditional exponential approximation η = 1); (2) a promising idea is to seek the best fit only for wavelengths λ > λ1, where λ1 will be chosen taking into account the real shape of aCDOM spectra. The mean value of the specific absorption coefficient (a*CDOM) at the wavelength 380 nm obtained in this study (0.44 L mg−1 m−1) is close to the values published in the literature, if we assume that a*CDOM (380) is calculated using the data of dissolved organic matter (DOM). The optically non-active fraction of DOM in our study was high and therefore a*CDOM (380) was considerably higher (1.01 L mg−1 m−1) than a*CDOM (380). The results of the present work could be used in the modeling of underwater light field as well as in the interpretation of radiation measurements and optical remote sensing results.

scholarly journals Photochemical production of polyols arising from significant photo-transformation of dissolved organic matter in the oligotrophic surface ocean

2014 ◽  
Vol 163 ◽  
pp. 10-18 ◽  
Author(s):  
Michael Gonsior ◽  
Norbert Hertkorn ◽  
Maureen H. Conte ◽  
William J. Cooper ◽  
David Bastviken ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Surface Ocean ◽  
Photochemical Production

Complexation of Dissolved Organic Matter with Trace Metal Ions in Natural Waters

2012 ◽  
pp. 769-849 ◽  
Author(s):  
Khan M. G. Mostofa ◽  
Cong-qiang Liu ◽  
Xinbin Feng ◽  
Takahito Yoshioka ◽  
Davide Vione ◽  
...  
Keyword(s):  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Trace Metal ◽  
Metal Ions ◽  
Natural Waters ◽  
Trace Metal Ions
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