Sensitized Photooxidation of Phenols by Fulvic Acid and in Natural Waters

1987 ◽  
Vol 21 (10) ◽  
pp. 957-964 ◽  
Author(s):  
Bruce C. Faust ◽  
Jurg. Hoigne
Keyword(s):  
Fulvic Acid ◽  
Natural Waters

Heavy Metal Binding Components of River Water

1975 ◽  
Vol 32 (10) ◽  
pp. 1755-1766 ◽  
Author(s):  
S. Ramamoorthy ◽  
D. J. Kushner
Keyword(s):  
Heavy Metal ◽  
Fulvic Acid ◽  
River Water ◽  
Metal Binding ◽  
Natural Waters ◽  
Binding Capacity ◽  
Binding Constants ◽  
Binding Ability ◽  
Ottawa River ◽  
Almost All

Ion-specific electrodes were used to measure the heavy metal (HM) binding capacity of river waters near Ottawa. Binding capacity was measured in unfiltered water and in water passed through filters retaining particles (0.45 μm) and macromolecules of molecular weight (MW) 45,000, 16,000 and 1,400. In the most studied water samples, almost all the Hg2+-binding ability passed through the smallest filter. Filters of different pore sizes retained substantial fractions of the binding ability towards other HM ions. Binding strengths and conditional binding constants were calculated for each HM ion and low MW Ottawa River water components.Binding in Ottawa River water was not due to HCO3− or CO32− ions; in the Rideau Canal, and probably in other bodies of water, such ions caused a substantial amount of binding. After complete ashing of Ottawa River water and reconstitution with deionized water almost all the HM binding ability was lost; thus, an organic compound(s) is responsible for binding.The binding pattern towards different HM ions of fulvic acid isolated from soil was different from that of unfiltered or filtered Ottawa River water. Fulvic acid is not the sole binding component of this water. These experiments suggest a way of assessing the importance of fulvic acid and other humic substances in HM binding by natural waters.

Effect of Chloride and Suwannee River Fulvic Acid on Cu Speciation: Implications to Cu Redox Transformations in Simulated Natural Waters

2020 ◽  
Vol 54 (4) ◽  
pp. 2334-2343 ◽  
Author(s):  
Guowei Xing ◽  
Shikha Garg ◽  
Christopher J. Miller ◽  
A. Ninh Pham ◽  
T. David Waite
Keyword(s):  
Fulvic Acid ◽  
Natural Waters ◽  
Redox Transformations ◽  
Suwannee River ◽  
Suwannee River Fulvic Acid

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.

ATRAZINE HYDROLYSIS IN SOILS: CATALYSIS BY THE ACIDIC FUNCTIONAL GROUPS OF FULVIC ACID

1985 ◽  
Vol 65 (3) ◽  
pp. 435-443 ◽  
Author(s):  
DONALD S. GAMBLE ◽  
SHAHAMAT U. KHAN
Keyword(s):  
Fulvic Acid ◽  
Functional Groups ◽  
Natural Waters ◽  
Acid Catalysis ◽  
Carboxyl Groups ◽  
Acid Solutions ◽  
Predictive Equation ◽  
Hydrogen Ions ◽  
Soil Solutions ◽  
Humic Materials

The catalysis of atrazine hydrolysis at 25.0 °C by the types of acidic functional groups found in humic materials has been investigated. No evidence of catalysis by carboxylate ions was observed. From a knowledge of the types and numbers of acid functional groups in a quantitatively characterized fulvic acid, and the distributions of their KA values it was found that hydrogen ions and undissociated carboxyl groups were the only catalytic agents. The carboxyl groups have a second-order kAH of 7.88 days −1∙M−1. Weakly acidic functional groups having [Formula: see text]showed no catalysis. A predictive equation has been produced for the half-life of atrazine in fulvic acid solutions at 25.0 °C. It represents a general class of equations which should permit the practical prediction of atrazine persistence in soil solutions and other natural waters. Key words: Atrazine hydrolysis, atrazine persistence, fulvic acid, fulvic acid carboxyls, acid catalysis, carboxyl catalysis

Potentiometric and Conformational Studies of the Acid-Base Properties of Fulvic Acid from Natural Waters

1983 ◽  
pp. 751-772 ◽  
Author(s):  
M. S. Varney ◽  
R. F. C. Mantoura ◽  
M. Whitfield ◽  
D. R. Turner ◽  
J. P. Riley
Keyword(s):  
Fulvic Acid ◽  
Natural Waters ◽  
Acid Base ◽  
Conformational Studies ◽  
Base Properties
Sign in / Sign up

Export Citation Format

Share Document