StatusThe thesis was presented on the 24 June, 2016
Approved by NCAA on the 6 October, 2016
Abstract– 1.07 Mb / in romanian
3.31 Mb /
The thesis comprises: Introduction, 4 chapters, bibliography of 241 titles, 7 annexes, total volume of 133 pages, 54 figures and 20 tables. The research results were published in 23 scientific papers.
Research field: 145.01. Ecological chemistry.
The aim of the thesis is to elucidate the particularities of chemical degradation of natural and industrial calcareous materials in the environment under the action of ammonia nitrogen compounds and accumulation of nitrates, calcium ions (hardness) and heavy metals in natural waters, to propose the measures for reduction of the calcium leaching and the degradation of materials that contain calcium carbonate by various optimization methods.
Objectives: to study the impact of ammonium compounds on natural and industrial calcareous materials; to establish the correlation between the content of nitrate, the calcium ions and hardness in underground waters; to elabore the process of soil fertilization with ammonium nitrogen fertilizers in order to diminish of soil chemical degradation and prevention of groundwater pollution; to highlight the additives as a protecting factor of the concrete against the corrosion to the action of ammonia nitrogen compounds.
Scientific novelty and originality. For the first time in the Republic of Moldova it was established that the factor of calcium ions accumulation (hardness increase) in underground waters correlates with the nitrate content, the final compound of ammonium ions nitrification, which confirms the phenomenon of carbonate solubilisation from nature in presence ammonium of compounds.
The solved scientific problem consists in scientific substantiation of ammonium compound influence on the resistance of biological limestone systems, natural minerals and of the concrete, which determined to elaborate the processes and the diminution schemes for soil and concrete chemical alteration in order to minimize of carbonate solubilisation process. The theoretical significance. Ammonia nitrogen compounds expose the calcareous materials to chemical degradation.
Applicative value of the work. The application of a calculated ratio of ammonia and phosphorus fertilizer in the soil, as well as the additives concrete, diminishes the carbonate solubilisation process. The proposed methods present the real opportunities for implementation in agriculture field and in the production of concrete. The impact on the shells of molluscs can be excluded by compliance of RM legislation on the content of ammonia nitrogen in discharged wastewaters.
The implementation of scientific results. The established optimum conditions lead to optimization of the soil fertilization process (patent) and of concrete production. The dissemination of the results concerning the composition of springʼs water to local public administration serves as an argument in order to take the measures to prevent pollution and to improve the natural water quality in territories. The scientific research results have been appreciated by the State Hydrometeorological Service and the Institute of Scientific Research in Constructions „INCERCOMˮ Î.S.