CHEMICAL PRINCIPLES OF WASTEWATER PURIFICATION FROM IONS OF MANGANESE, COPPER AND IRON

It is reasonable to process wastewater containing manganese ions due to the fact that after the fall of the Soviet Union the main manganese deposits remain outside Russia. That is why it is very important for the Russian Federation to find new sources of different manganese compounds widely used in metallurgy and other industries. Electrochemical methods are considered to be the most promising trend in the technology of water purification. These methods provide maximum concentration and recovery of valuable components from industrial solutions. Besides, they are environmentally safe and make it possible to avoid «secondary» water pollution with anion and cation residues which are typical for reagent methods. The main idea of the suggested method can be described in the following way: molecular chlorine is formed in the process of electro-treatment of chloride-containing solutions; this molecular chlorine reacts with water and forms active forms of chlorine-containing oxidizing agents, so called “active chlorine”. Then the “active chlorine” comes into contact with Mn (II), the redox process takes place and Mn²⁺ ions oxidize into insoluble Mn³⁺ and Mn⁴⁺ forms. While developing the technology of deposition of Mn²⁺ ions from wastewater a set of sequentially executed operations, including pre-staged extraction of copper ions and iron, is performed. Тhe suggested complex technology of the gradual recovery of copper, iron and manganese ions is quite simple and efficient; it does not require sophisticated equipment and can be used both separately and as a part of the existing system of wastewater purification facilities. Тhis technology can be used for establishing a closed cycle water supply at the mining-and-processing enterprises. Тhe products produced by this technology are the high quality raw material for metallurgy. The introduction of this technology will significantly reduce the environmental burden in the region.