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Characterization of aquatic humic substances
Author(s) -
Rodríguez Francisco J.,
Núñez Luis A.
Publication year - 2011
Publication title -
water and environment journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 37
eISSN - 1747-6593
pISSN - 1747-6585
DOI - 10.1111/j.1747-6593.2009.00205.x
Subject(s) - chemistry , humic acid , solubility , adsorption , environmental chemistry , aromaticity , absorbance , organic matter , natural organic matter , infrared spectroscopy , dissolved organic carbon , fulvic acid , elemental analysis , water soluble , chromatography , organic chemistry , molecule , fertilizer
Aquatic natural organic matter (NOM) is composed of a large variety of compounds. In this study, NOM from Uzquiza Reservoir in Burgos (Spain) was fractionated using a resin adsorption procedure, and three humic substances – natural fulvic and humic acids (NFA and NHA, respectively) extracted from the mentioned reservoir and a commercially supplied humic acid (CHA) – were characterized by molecular weight (MW) distribution, elemental composition, organic acidity and ultraviolet and infrared spectroscopy. The results indicate that Uzquiza Reservoir NOM is mainly composed of fulvic acids (45%) and low MW hydrophilic acids (27%). MWs obtained are in the following order: CHA (4500 Da)>NHA (2500 Da)>NFA (1000 Da). Both humic acids (CHA and NHA) have the highest specific UV absorbance values (SUVA, an aromaticity indicator) whereas NFA shows a higher total and carboxylic acidity, which is in accordance with its higher solubility in water. Infrared spectra confirm these results.