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Showing 1 to 20 of 36 for “"Fulvic acid"”.
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THE INFLUENCE OF FULVIC ACID ON COPPER(II), CADMIUM(II) AND ZINC(II) REMOVAL FROM DRINKING WATER BY ALUM COAGULATION AND COPPER(II) AND CADMIUM(II) COMPLEXING CAPACITY MEASUREMENTS OF FULVIC ACID AND NATURAL FRESHWATER SAMPLES BY DIALYSIS TITRATION
… cases by a soil-derived humic material called fulvic acid. The role of natural humics in the transport and speciation of dissolved metal ions in drinking water sources, particularly health hazards like Cd('2+), is investigated. Some properties of soil-derived fulvic acid (SFA) were also …
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Evaluation of Chelex 100 and Assessing the Impact of Fulvic Acid (NOM) on Copper Toxicity and Bioavailability to Americamysis bahia
… of copper in the presence of Suwannee River Fulvic Acid, which served as a source of NOM. Static or static renewal tests, based on EPA method OPPTS 850.1035 with a minimum of 10 mysid shrimp per test condition, were used to determine the LC50 and EC50 of copper and the effects of NOM. Test …
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CADMIUM(II), LEAD(II), AND COPPER(II) COMPLEXATION BY FULVIC ACIDS DERIVED FROM SOIL AND WATER: ION-SELECTIVE ELECTRODE AND SPECTROFLUOROMETRIC STUDIES
… study describes complexation of metal ions by fulvic acid, the acid soluble fraction of organic matter found in soils (SFA) and water bodies (WFA). Such complexation affects the toxicity and geochemical mobility of heavy-metal ions. All the work was performed with two previously isolated and …
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NMR STRUCTURAL INVESTIGATIONS OF AQUATIC HUMIC SUBSTANCES (PYRAZOLINE, 1,3-DIPOLAR ADDITION, NITROGEN-15).
… functionality of a series of aquatic humic and fulvic acids was examined by methylating the samples with ¹³C-enriched reagents and looking at the ¹³C NMR of the resulting methyl esters and ethers. The methylation procedure entailed methylation with ¹³C-diazomethane followed by permethylation …
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A computer simulation of the protonation and metal complexation properties of fulvic acids
… interactions between binding sites on a fulvic acid molecule are incorporated into a computer model for the simulation of fulvic acid cation equilibria. A preliminary investigation into the influence of nitrogen containing constituents on simulated metal complexation results is also …
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The characterization of humic substances in seawater
… and physical characteristics of both humic acid and fulvic acid fractions were studied. The elemental composition, the acidimetric titration characteristics, the l3C: l2C ratios, and the ultraviolet-visible, fluorescence, and infrared spectra were determined. Molecular weight distributions …
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Determination of Henry's Law Constants of Odorous Contaminants and Their Application to Human Perception
… synthesized from poly-unsaturated fatty acids by diatoms like Synura and has cucumber and fishy odors detectable at 10-40 ng/L levels. The new static headspace method uses standard glassware used in odor-analyses. 500 mL wide-mouth Erlenmeyer flasks were modified with septum sampling …
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Targeted Degradation of Trinitrotoluene Using Iron (II)-Cyclodextrin-Peroxide Systems
… water system with interfering substance - humic acid, which tends to associate with TNT, the addition of cyclodextrin helped to improve the efficiency of Fenton degradation. This technique has also been successfully applied to remediate TNT contaminated soil systems (sand). Four systems were …
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Removing Soluble Organic Contaminants From Water Supplies by Lime Softening
… process modifications were investigated using a fulvic acid extracted from a local groundwater supply. In phase II the molecular characteristics of contaminants pertinent to their removal were examined by selecting a wide range of natural and synthetic organic substances and testing their removal …
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Evaluation of reactive cap sorbents for in-situ remediation of contaminated sediments
… investigated the interferences caused by humic acid on the adsorption of co-planar and non-co-planar polychlorinated biphenyls (PCBs) including 2-chlorobiphenyl, 2, 2', 5, 5'-tetrachlorobiphenyl, 3, 3', 4, 4'-tetrachlorobiphenyl, 2, 2', 4, 4', 5, 5'-hexachlorobiphenyl and 3, 3', 4, 4', 5, …
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Characterization and treatment of organic matter, UV quenching substances, and organic nitrogen in landfill leachates
… Humic substances were also fractionated to humic acid (HA), fulvic acid (FA), and hydrophilic (Hpi) components before being subjected to size fractionation to determine UV254 absorbance and organic fractions. Particle size and hydrophobic-hydrophilic fractionation were conducted in series to …
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Studies on the analytical chemistry of chromium in aqueous solutions
… studied. The results indicate that when humic acid or fulvic acid is present, the amount of Cr(VI) reduced to Cr(III) is both time- and pH-dependent.
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Caractérisation de la matière organique dissoute de l'estuaire du Saint-Laurent par un système HPLC-FTIR
… characterization of ultrafiltered DOM (UDOM) and fulvic acid (FA) samples from the St. Lawrence Estuary and its tributaries and the quantification of functional groups present in the different size fractions. Compositional differences were observed in function of molecular size, the geographic …
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Humic Substances Removal by Activated Carbon
A commercial humic acid and a fulvic acid extracted from peat were used to evaluate the removal of humic substances by various activated carbons. Different analytical methods were investigated to determine humic substances as possible indicators of chloroform formation potential. Total organic …
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Characterization of chemically fixed nitrogen-15-labeled liquid anhydrous ammonia and of biologically immobilized nitrogen-15 in typical Illinois mollisols
… and the extracted N was fractionated into humic acid (HA) and fulvic acid (FA). The residual soil was then extracted with 0.1 M NaOH and 99% (v/v) dimethyl sulfoxide (DMSO). The FA fraction was further separated into low molecular weight (LMW) and high molecular weight (HMW) components by …
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Complexation state of iron and copper in ambient particulate matter and its effect on the oxidative potential
… by applying it on a mixture of Suwannee River fulvic acid (SRFA) and Fe or Cu. SRFA is selected as a model compound as it represents the humic-like substances present in ambient PM, which are believed to be complexed with Fe and Cu. The results show that a significant amount of iron pre-mixed …
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Arsenic Adsorption on Iron Oxides in the Presence of Soluble Organic Carbon and the Influence of Arsenic on Radish and Lettuce Development
… in the presence of either a peat humic acid (Hap), a Suwannee River Fulvic Acid (FA) (IHSS) or citric acid (CA). Adsorption edges and kinetic experiments were used to examine the effects of equimolar concentrations of organic adsorbates on arsenic adsorption. Adsorption envelopes were …
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Investigation of Lead Hydrolytic Polymerization and Interactions with Organic Ligands in the Soil/Sediment-Water Environment
… organically complexed. Complexation of Pb with fulvic acid provided new information on the extent of Pb association with soluble organic matter. The overall results of this research have provided new and useful information regarding Pb speciation in environmental samples. The results, in several …
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