Humic acids are generally defined operationally as those decomposir tion products of plants and animals that comprise the base-soluble, 2 acidand alcohol-insoluble fractions of the soil. These materials are of interest because of their geological significance, possible nutritive properties, involvement of biological processes, and the challenge 3 afforded by their chemical and structural comple...

The potassium permanganate oxidation of methylated humic acid from a Spanish lignite yielded mainly straight-chain alkanes together with a mixture of fatty acids, methyl straight-chain alkyl ketones, aliphatic dicarboxylic, phenolic and benzenecarboxylic acids. Furthermore, some unusual compounds such as dehydroabietic and bromohydroxybenzoic acids and bis(2-ethylhexyl)phthalate were also ident...

Humic acids (Fluka), chlorinated to carbon:chlorine (C:Cl) ratios of 1:1 and 1:0.3, were administered to B6C3F1 mice, 50 males and 50 females per group, in the drinking water at a total organic carbon (TOC) level of 0.5 g/L. The mice were 6 to 8 weeks old at the beginning of the bioassays. The doses used were based on short-term (8 weeks) evaluations for toxicity, palatability, and weight gain....

The complexation of organic solutes with dissolved humic substances (HS) is an important process for the fate of these chemicals in natural aquatic systems. We used the Fluorescence Quenching technique to study the interactions between napropamide, a common herbicide, and ten dissolved humic or fulvic acids extracted from different soils and peats. The primary mechanism of napropamide quenching...

humic substances as an active part of soil organic maters can improve germination and seedling properties, plant establishment and plant growth. in order to study the effects of different concentrations of humic and fulvic acids on germination and seedling properties of two varieties of triticale (triticosecale hexaploide lart.), a factorial experiment based on a completely randomized design wi...

A class of organic molecules extracted from atmospheric aerosol particles and isolated from fog and cloud water has been termed HUmic-LIke Substances (HULIS) due to a certain resemblance to terrestrial and aquatic humic and fulvic acids. In light of the interest that this class of atmospheric compounds currently attracts, we comprehensively review HULIS properties, as well as laboratory and fie...

Humic substances are routinely applied to creeping bentgrass putting greens during times of stress to improve turf health. Confounding effects of added nutrients and other ingredients make it difficult to separate the effects caused by the organic material from additional effects of the supplemental ingredients. Claims made in advertising and marketing of the effectiveness of humic substance pr...

In this study, the effects were investigated of salinity, foliar and soil applications of humic substances on the growth and mineral nutrients uptake of Corn (Hagein, Fardy10), and the comparison was carried out of the soil and foliar applications of humic acid treatments at different NaCl levels. Soil organic contents are one of the most important parts that they directly affect the soil ferti...

The complex nature of natural organic matter (NOM), and the impact of this matter on drinking water quality have necessitated the characterization studies of NOM. A fluorescence technique for the characterization of NOM in Malaysian river water is reported. Water samples from several river sampling sites were collected and concentrated using a low-pressure reverse osmosis (LPROM). Solid phase e...

The molecular organization of humic acids in different aqueous solutions was studied over a wide concentration range (0.01-10 g·dm-3). Solutions of humic acids were prepared in three different media: NaOH, NaCl, and NaOH neutralized by HCl after dissolution of the humic sample. Potentiometry, conductometry, densitometry, and high resolution ultrasound spectrometry were used in order to investig...