OPTIMIZATION OF THE REAGENT METHOD OF CLEANING OF COPPER (II) -STATER WATER

Abstract

Sewage water of electrochemical manufactures that exist at almost every machine and instrument making enterprise are the main source of the heavy metals that flow into the reservoir. The greatest interest is the purification of sewage from ions of copper (II). From the variety of available methods for purifying water from heavy metal ions, the most potentially suitable are traditional reagent methods as they are versatile, easy to operate and cheap. But they do not always provide theadmissible concentrations. All this necessitates the development and implementation of new modern technologies that allow ensuring high efficiency of the processes of purification from heavy metal ions. This also gives possibility of creating integrated technologies with a closed cycle of water consumption on their basis. Recently, the interest in derivatives of iron-synthetic acid has increased considerably; ferrocyanides acquire a rapidly growing practical value. It is known that ferrocyanides of heavy metals have very low solubility, therefore it was suggested to use potassium ferocyanide as a precipitant in order to remove copper ions from the researched solutions. Since the copper (II) ferrocyanides can form stable colloidal systems, settling solutions will be a long-term and technologically not always justifiable solution, because of its inappropriate usage as an independent method of purification. Typically, this method is combined with the filtering method. In this work, the effectiveness of the flocculantZetag 7547 was investigated. The purpose of this work is to study the features of sewage purification from copper ions (II) applying precipitation method using potassium ferrocyanide and water soluble polyelectrolyte Zetag 7547. To achieve this goal, the following tasks need to be solved: increase the depth of the deposition reaction; intensify the processes of aggregation and sedimentation of particles of the dispersed phase. To reach the optimal conditions for reagent treatment of wastewater, preliminary studies of the pH solution influence on the solubility of the formed copper (II) ferrocyanates have been made. Studies have shown that optimal pH values of precipitation of Cu (II) are within the range of 6.5 to 7.5. In order to intensify the reagent water purification, it was suggested to make its processed flocculation. When used in low concentrations, Zetag-7547 flocculant decreases potassium ferrocyanide significantly from aqueous solutions. From obtained results list of ratios of concentrations of potassium ferrocyanide and flocculant, which should be used to purify water from ions copper (II) were selected. After settling in the solution, a part of coarse dispersed impuritiesremain. They were removed by filtration, which increased the degree of purification up to 99%. Thus, in current research the processes of formation of copper (II) ferrocyanides complexes depending on the pH environment are analyzed, the conditions of reagent treatment of water using Zetag 7547 flocculantare set. The most effective methods of controlling the process of flocculation are shown. The amount of solid waste is reduced.