scholarly journals Spatial and temporal variations and factors controlling the concentrations of hydrogen peroxide and organic peroxides in rivers

2009 ◽  
Vol 6 (6) ◽  
pp. 524 ◽  
Author(s):  
Khan M. G. Mostofa ◽  
Hiroshi Sakugawa
Keyword(s):  
Hydrogen Peroxide ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Fulvic Acid ◽  
Natural Waters ◽  
H2o2 Production ◽  
Organic Peroxides ◽  
Fluorescent Whitening Agent ◽  
River Waters ◽  
Japanese Rivers

Environmental context. Hydrogen peroxide (H2O2) and organic peroxides (ROOH) are ubiquitously present in natural waters and primarily essential for several redox reactions. This study examines the effects of various dissolved organic substances on the formation of H2O2 and ROOH and their relationship with different water quality parameters in two Japanese rivers. This study suggests that fulvic acid is primarily responsible for production of H2O2 and ROOH in river waters. Abstract. Hydrogen peroxide (H2O2) and organic peroxides (ROOH) were examined in water samples collected from the upstream and downstream sites of two Japanese rivers (the Kurose and the Ohta). H2O2 concentrations during monthly measurements varied between 6 and 213 nM in the Kurose River and 33 and 188 nM in the Ohta River. ROOH varied between 0 and 73 nM in the Kurose River and 1 and 80 nM in the Ohta. Concentrations of peroxides were higher during the summer months than in winter. H2O2 concentrations correlated well with the measured content of dissolved organic carbon and/or the fluorescence intensity of the fluorescent dissolved organic matter (FDOM) in the water from these rivers, which suggested that the dissolved organic matter and FDOM are the major sources of H2O2. Further characterisation of FDOM components by excitation emission matrix spectroscopy and parallel factor (PARAFAC) analysis indicated that fulvic acid is a dominant source of H2O2 in river waters, which accounted for 23–70% of H2O2 production in the Ohta River, 25–61% in the upstream and 28–63% in the downstream waters of the Kurose River, respectively. A fluorescent whitening agent and its photoproduct (4-biphenyl carboxaldehyde) together contributed 3–7% of H2O2 production in the downstream waters of the Kurose River. Tryptophan-like substances were a minor source of H2O2 (<1%) in both rivers. An increase in the H2O2 concentration was observed in the diurnal samples collected at noon compared with the samples collected during the period before sunrise and after sunset, thus indicating that H2O2 was produced photochemically. This study demonstrates that H2O2 and ROOH are produced mainly from the photodegradation of FDOMs, such as fulvic acid.

scholarly journals Interference of dissolved organic matter and its constituents on the accurate determination of hydrogen peroxide in water

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Jianbiao Peng ◽  
Ya Zhang ◽  
Jianhua Li ◽  
Xinan Wu ◽  
Mengjie Wang ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Organic Matter ◽  
Dissolved Organic Matter ◽  
Natural Waters ◽  
Accurate Determination ◽  
Quantitative Structure Activity Relationship ◽  
Relationship Model ◽  
Order Of Magnitude ◽  
20 Nm

AbstractHydrogen peroxide (H2O2) is ubiquitous in natural waters, and plays an important role in both biological and chemical processes. This study investigated the influence of dissolved organic matter (DOM) and its substituents on the accurate measurement of H2O2 by peroxidase-mediated depletion of scopoletin fluorescence method which is one of the most widely used methods for the determination of low concentration H2O2 in water. Six DOM and its 24 substituents interfered the determination of H2O2 at environmentally relevant concentration of 200 nM with different levels except 2,6-dimethoxy-1,4-benzoquinone and benzoic acid, which may be associated with origin and types of DOM, and numbers and position of active functional groups in DOM constituents. Each substance concentration and the corresponding decreasing ratio to the measured H2O2 concentration was fitted well to the linear model (R2 > 0.9), and the obtained interfering ratios (k, (mgC L−1)−1), expressing the degree of DOM or its substituents per unit concentration to the measurement of H2O2, were approximate for DOM, but the order of magnitude of k values of DOM constituents took on a large span from 10–3 to 10–7. When DOM levels exceed 0.1 mgC L−1 or its substituent concentration is at nM level (low to 20 nM), the H2O2 content will be underestimated substantially. A quantitative structure–activity relationship model with remarkable stability and strong predictability for the k of DOM substituents to H2O2 measurement was established, and the k was related to the electron transfer capacity, hydrophobicity and stability of these compounds.

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 &lt; 1 (in the case of traditional exponential approximation η = 1); (2) a promising idea is to seek the best fit only for wavelengths λ &gt; 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.

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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