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Due to numerous and valuable properties of humic substances, preparations produced from alternative organic materials have been widely used in agriculture, bioremediations, dietary supplements and others. In addition to well-known humic acids, fulvic acids (FA) are a valuable product with a wide range of applications. The aim of performed examinations was to assess the thermal and physicochemical properties of FA obtained from lignite and peat using simplified conventional and ultrasound-assisted methods. DSC coupled with TG and MS, 13C NMR, FTIR spectroscopy and differential pulse voltammetry has been used to examine extracted FA. Depending on the source of FA and the extraction method applied, their structure and properties differ. Obtained FA fractions varied for both tested raw materials in terms of analyzed carbon structures, and the highest discrepancy was observed for carbonyl groups (20.2 pp) in fractions obtained by conventional extraction. The use of the ultrasound-assisted extraction (UAE), in comparison with the traditional method, lowered the ratio of carbon in carbonyl groups by 8.4 pp and increased the ratio of aromatic and aliphatic carbon by 3.5 and 4.9 pp, respectively, for FA obtained from lignite. As for FA obtained from peat, the UAE effect appeared to be less impactful in terms of structural changes. Thermal analysis showed that the products were thermally stable up to 100 °C, and the simplified extraction resulted in the creation of mineral-organic structures that decomposed at unusually high temperatures. Simplifying the extraction process, by excluding inorganic purification and protonation of obtained FA fractions, greatly affects product quality and limits its possible application. [ABSTRACT FROM AUTHOR]

Fertilisers containing ammonium nitrate are the most efficient sources of nitrogen used in agriculture. The major hazard associated with production, storage and transport of materials containing this compound is its liability to rapid decomposition, or even detonation under certain conditions. Properly selected calcium and magnesium carbonates may increase the thermal stability of ammonium nitrate. The aim of this research was to determine the influence of the carbonate mineral type and composition on phase transitions and decomposition process of fertiliser-grade ammonium nitrate. The article focuses on the methodology of thermal analysis of samples containing ammonium nitrate with carbonates and points out the phenomena and thermal characteristics that should be taken into consideration when testing fertiliser mixtures. Two different sample preparation methods allowed for investigating processes that may occur in inappropriate storage and transport conditions as well as during the production of fertiliser. The measurements were taken using techniques of differential thermal analysis and thermogravimetry coupled with mass spectrometry. The results showed that too high a level of carbonates reactivity can cause problems during the production of fertiliser, reducing the effectiveness of the filler in a final product. [ABSTRACT FROM AUTHOR]