Observing changes in soil organic matter (SOM) is a fundamental part of defining the carbon cycle in natural and cultivated environments. However, relying on changes in the mass of soil C over short periods often produces conflicting results because of errors associated with sampling and analysis. In addition, C mass balance studies provide little interpretation of processes or turnover of spec...

BACKGROUND Un-doped and N-doped TiO2 nano-particles with different nitrogen contents were successfully synthesized by a simple sol-gel method, and were characterized by X-ray diffraction, field emission scanning electron microscopy, Energy dispersive X-ray analysis and UV-visible diffuse reflectance spectra techniques. Then enhancement of sonocatalytic degradation of humic acid by un-doped and ...

This paper mainly studied transformation characteristics of humic acid in aqueous medium from coal-mining region of Pingdingshan. To achieve the research purpose, we carried out soil columns experiment. In this experiment, humic acid solution is used as water sample, meanwhile, marl rock are used as testing rock sample. Soon after the experiment, three-dimensional fluorescence technology was to...

High cation exchange capacity and organic matter content of crude humic substances from compost could be exploited to reduce ammonia loss from urea and to as well improve rice growth and soil chemical properties for efficient nutrients utilization in lowland rice cultivation. Close-dynamic air flow system was used to determine the effects of crude humic substances on ammonia volatilization. A p...

To characterize organic nitrogen present in cattle manure compost, a hot-water extract of the compost along with an acid-insoluble (humic acid-like) fraction either treated with alkali or laccase or untreated were separated by size-exclusion high-performance liquid chromatography (SE-HPLC). Nitrogen was then detected by chemiluminescent nitrogen detection (CLND), and humic acid-like substances ...

Anaerobic oxidation of [1,2-14C]vinyl chloride and [1, 2-14C]dichloroethene to 14CO2 under humic acid-reducing conditions was demonstrated. The results indicate that waterborne contaminants can be oxidized by using humic acid compounds as electron acceptors and suggest that natural aquatic systems have a much larger capacity for contaminant oxidation than previously thought.

The five major reductive degradation products of TNT-4ADNT (4-amino-2,6-dinitrotoluene), 2ADNT (2-amino-4,6-dinitrotoluene), 2,4DANT (2,4-diamino-6-nitrotoluene), 2,6DANT (2,6-diamino-4-nitrotoluene), and TAT (2,4,6-triaminotoluene)-labeled with 15N in the amine positions, were reacted with the IHSS soil humic acid and analyzed by 15N NMR spectrometry. In the absence of catalysts, all five amin...

The sorption properties of tetracycline were compared between a coal humic acid (CHA) and a soil humic acid (SHA) under various solution chemistry conditions. Structural characteristics of the two humic acids were quantified in detail by elemental analysis, solid-state (13)C nuclear magnetic resonance (NMR), acid-base titration, and Zeta potential measurement. The CHA consists primarily of poly...

Remediating soils with heavy metals contamination is a significant challenge. This study investigated the co-remediation effect when paired soil amendment mixtures were used to treat soil contaminated by Pb, Cd, and Zn. The three mixed amendments are: 1) micro particle hydroxyapatite (mHAP) and humic acid 2) nano particle hydroxyapatite (nHAP) and humic acid 3) sepiolite and humic acid. Co-reme...