Search

Due to their properties, humic acids (HA) can interact with macro- and micronutrients and retain plant nutrients in the soil profile. The aim of the presented work was to develop a new integrated 4-step process for the isolation of humic acids from peat with their simultaneous enrichment in macronutrients. The study demonstrated the possibility of replacing traditional solutions used in the extraction of humic acids with solutions that are a source of macronutrients. For the alkaline extraction step, a process assisted with ultrasound was implemented, which allowed to increase the efficiency of humic acids isolation. Optimization of this step has shown that, with the application of ultrasound in the new procedure, it is possible to obtain the humic acids isolation efficiency of more than 60%. The qualitative analysis of the products obtained confirmed the presence of structures characteristic of humic acids, including key functional groups.

Ammonium nitrate (AN) is considered to be a very hazardous and difficult to handle component of mineral fertilizers. Differential thermal analysis coupled with thermogravimetry and mass spectrometry was used to determine the possible inhibiting effect of selected magnesium compounds on thermal decomposition of AN. Each additive was mixed with AN to create samples with AN:magnesium compound mass ratios of 4:1, 9:1 and 49:1. Most of analyzed compounds enhanced thermal stability of ammonium nitrate, increasing the temperature of the beginning of exothermic decomposition and decreasing the amount of generated heat. Magnesium chloride hexahydrate was determined to accelerate the decomposition of AN while magnesium sulphate, sulphate heptahydrate, nitrate hexahydrate together with magnesite and dolomite minerals were defined as inhibiting agents.