We examined the molecular-level interactions of aromatic compounds with a humic acid that was extensively characterized with one- and two-dimensional nuclear magnetic resonance (NMR) spectroscopy. Interactions of target compounds were evaluated by monitoring their NMR relaxation properties. Solid-state NMR revealed that the humic sample contains paraffinic carbon (31%), substituted aliphatic ca...

............................................................................. 1 Humic acids....................................................................... 3 Introduction.................................................................... 1 Field studies....................................................................... 4 Analytical developments..........................................

agroecology emphasizes the use of organic materials in agriculture. the organic acids are important sources of organic materials. in order to study the effect of different levels of humic acid on yield and yield components of corn (zea mays l.) an experiment was conducted at research station, faculty of agriculture, ferdowsi university of mashhad, iran, during 2009. the experiment was conducted...

The density of humic acids and humic like substances (HULIS) from fresh and aged wood burning and pollution aerosol particles E. Dinar, T. F. Mentel, and Y. Rudich Department of Environmental Sciences, Weizmann Institute of Science, Rehovot 76100, Israel Institute for Tropospheric Chemistry, Research Center Jülich, Jülich, Germany Received: 25 July 2006 – Accepted: 7 August 2006 – Published: 11...

Metronidazole is a nitroimidazole antibiotic derivative used in humans against anaerobic bacteria and protozoa. In light of the recent detection of metronidazole in hospital wastes, sewage treatment plants, and surface waters, along with its known sensitivity toward photolytical degradation, this study aimed to model the photolysis in environmental waters by sunlight as a natural attenuation pr...

Soil organic matter stability and transformation affected by agriculture is a global problem of great concern. This study aimed to reveal structural changes in humic molecules under conventional soil tillage Cambisols the Transbaikal area. Humic acids were isolated from humus horizons native arable variants Eutric Cambisol Cryic (gleyic, humic, loamic) forest steppe, Haplic (arenic, protocalcic...

The assessment of physico-chemical properties in forest soils affected by fires was evaluated using near infrared reflectance (NIR) spectroscopy coupled with chemometric methods. In order to describe the soil properties, measurements were taken of the total organic carbon on solid phase, the total nitrogen content, the organic carbon and the specific absorbences at 254 and 280 nm of humic subst...

Humic substances, i.e. dark paramagnetic polymeric anionic polyelectrolytes, belong to the most widespread macromolecular substances of biogenic origin in soil and aquatic environments. The exact structure of humic substances is unknown because of their complexity resulting from unrecurring precursors, from their composition and their process of synthesis. Degradation processes of these substan...

The composition of isolated natural organic matter (NOM) fractions was studied by means of high pressure size-exclusion chromatography (HP-SEC), specific ultraviolet absorbance (SUVA) at 254 nm, total luminescence spectroscopy (TLS) and synchronous scanning fluorescence measurements. The HPSEC, SUVA and TLS studies revealed that humic acids (HA) and hydrophobic acids (HOA) are composed of compl...