Humic acid, solvent extractable

NOTE There are various types of organic contaminants that can be present in boiler FW, including trace amounts of pesticides and naturally occurring humic, fulvic, and tannic acids, and solvent-extractable oily matter, such as nonvolatile hydrocarbons, vegetable oils, animal fats, waxes, soaps, greases, and the like. 

Bioreactors containing an nndefined anaerobic consortinm rednced TNT to 2,4,6-triaminotoluene (TAT) in the presence of glncose (Dann et al. 1998). The sorption of TAT to montmorillonite clay was irreversible, and the snbstrate conld not be released by solvent extraction or by acid or alkaline treatment. Similar resnlts were obtained with humic acids in which covalent reactions with carbonyl or activated C=C bonding presumably occurred. Results from laboratory experiments nsing i C-labeled TNT in reactors to which... 

The aqueous fraction was acidified to pH 1 with 6N HC1, and the small amount of humic acids which precipitated was removed by filtration. The filtrate was extracted three times with 100-ml portions of ethyl acetate. The organic extracts were combined, dried over anhydrous sodium sulfate, and filtered. The solvent was removed by rotary evaporation and the residue contained the freed byproducts from the hydrolyzed esterified and insoluble-bound compounds. 

Analysis for total petroleum hydrocarbons (EPA Method 418.1) provides a one-number value of the petroleum hydrocarbons in a given environmental medium. It does not, however, provide information on the composition (i.e., individual constituents) of the hydrocarbon mixture. The amount of hydrocarbon contaminants measured by this method depends on the ability of the solvent used to extract the hydrocarbon from the environmental media and the absorption of infrared light (infrared spectroscopy) by the hydrocarbons in the solvent extract. The method is not specific to hydrocarbons and does not always indicate petroleum contamination, since humic acid, a nonpetroleum material and a constituents of many soils, can be detected by this method. 

Presence of humic acids, lignin Solvent extraction ... 

Preparation of Fulvic and Humic Acids. Waxes, resins, and other substances soluble in organic solvents were removed by successive extractions with petroleum ether (35-60°), chloroform, and ethyl acetate. These extractions removed of the original material. 

The variation in the weight percentage of tqtal solvent extractable (TSE) material (extraction with chloroform/methanol/toluene) and solvent extractable humic acid (SEHA) for the coal samples is... 

In this chapter, humic substances, humic acid, fulvic acid, and humin refer to material extracted from lake sediments that were initially extracted with an organic solvent. Where a different extraction method was used, it is described in the text. 

Povoledo et al. (1975) also observed absorption bands at 410 and 670 nm for lake humic acids extracted without prior organic solvent extraction. They concluded that the pigments responsible for these bands were chlorophyll derivatives, notably pheophytin a, and reported the approximate content in humic acid from a Canadian lake sediment was 0. %. They reported that other pigments (e.g., carotenoids) were also present in lake humic acids without prior organic solvent extraction. Bourbonniere and Meyers (1978) extracted humic substances from Lake Huron surficial sediment without prior organic solvent extraction and measured visible spectra in 0.05N NaHC03 solution (pH 7.3-8.7) which gave 465/ 665 values of 3.92 for humic acid and 10.66 for fulvic acids. 

Fatty acids in humin from Lake Haruna sediments were analyzed for the fraction obtained by solvent (benzene/methanol 6 4) extraction followed by saponification 2N KOH aqueous solution at 200°C for 3 hours) extraction (Yamamoto and Ishiwatari, 1981). The fatty acids were composed of normal C12-C30 saturated monocarboxylic acids (maximum at Cig), unsaturated (Cie and Cis), and branched (C13, C15, and Cn) monocarboxylic acids. The fatty acid distribution in humin resembled that in humic acid. Total fatty acids accounted for 1.0% of the humin and probably originated from algae, bacteria, and higher plants. 

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