MODELLING AND CAICULATIONS OF THE OXIGEN REGIME DURING THE EXTRACTION OF IRON FROM GROUNDWATER BY FILTRATION

Abstract

On the base of the simplification of the general mathematics models of the iron removal the engineer calculation methods of the removing of the iron combinations from the ground waters by the filtration on the refine filters and at the well filter colmatation are proposed. The analysis and the comparative value of the proposed methods are carried out. In most regions of Ukraine, aquifers, from which water is finly taken for the population, have an increased iron content, which significantly exceeds the standarts. Is modern conditions, the most widespread method of extracting compounds from waters is filtering through granular loading from natural or artificial granular materials in special installations, the main element of which is a filter. Under normal conditions in groundwater in the absence of dissolved oxygen and other oxidizing agents, dissolved iron is mainly present in the form of Fe2+ ions or its unstable protective forms of various salts. When interacting with dissolved oxygen, which is fed into the water, divalent iron is oxidized to trivalent, and then hydrolyzed into lumpy or suspended iron hydroxide in the form of silt flakes. On the basis of the implementation of a more general mathematical problem and the performance of the comparative analysis carried out tat the same time, the article proposes calculation methods that allow assessing the influence of the oxygen regime. The perfomed analysis shoved that in condition of oxygen deficiency, a simpler model can be adopted. Taking into account that in the case of a homogeneous filter, a more intense accumulation of sludge occurs in the upper layers, then an important characteristic during design and operation is the determination of the concentration of the amount of sludge near the upper border of the filter.