Vakal V. Reduction the technogenic load on the environment when using the nitrogen fertilizers with phosphorus-containing coating

The dissertation is devoted to solving the scientific and practical problem of reducing man-made chemical pollution of the environment through the development and introduction of environmentally safe organo-mineral fertilizers with the use of raw materials of Ukrainian phosphorites and peat. The analysis of ways of increasing the nitrogen fertilizer use efficiency showed that their encapsulation with mineral and natural components with modification of their organic component allows to minimize environmental risk from environmental pollution by nitrates, heavy metals and radionuclides. The peculiarities of obtaining the superphosphate from the phosphate-glauconite concentrate of the Karpivskyi deposit, characterized by high digestible P2O5 value, have been experimentally investigated in the sulfate-acid method. A mathematical model of the kinetics of water-soluble nitrogen leaching from a capsule granule was developed, that allows to calculate the change in the concentration of nitrogen leached from different types of fertilizers over time. The technological scheme of the process of obtaining the phosphate-containing coating on granules of nitrogen fertilizers has been developed and its testing has been carried out in experimental and industrial conditions. It is established that by the technology of local cultivation of soils the rate of application of encapsulated fertilizers can be reduced by 2–3 times, which allows to reduce the agrogenic load on the soil layer. An ecological and economic assessment of the reduction of technogenic load on the environment in the application of new types of fertilizers by calculating the hazard coefficient and environmental factor of encapsulated fertilizers shows that the developed composition of fertilizers can be attributed to environmentally safe fertilizers.