Application of Novel Ferritization-Based Method for the Treatment of Chromium-Containing Wastewater

Currently, development of resource-saving technologies for industrial wastewater treatment with further utilization of residuals is highly relevant. In this work, for the first time, advanced ferritization method with energy-saving AC-magnetic field activation was applied for the treatment of concentrated chromium-containing wastewater-exhausted chromium electrolytes. An experimental setup has been created to test the basic parameters of the ferritization process. The best generation values of AC-magnetic field activation for ferritization process were determined: amplitude of magnetic induction of 0.14 T and pulse frequency of 1 Hz. The optimal concentration ratio of iron to chromium ions 10:1 in the reaction mixture of ferritization was also established. The degree of removal of chromium ions from exhausted electrolyte of 99.96% was achieved. Purified water meets the requirements for its reuse in galvanic facilities and thus provides for implementation of circulating water supply at industrial enterprises. Structural analysis of the sediments by X-ray diffraction indicates the formation of stable crystalline ferromagnetic phases, mainly, chromium ferrite. The analysis of obtained data confirms the prospects of using energy-saving ferritization with AC-magnetic field activation instead of traditional thermal one. High chemical stability of sediments, obtained after wastewater treatment, allows to carry out safe utilization of this waste to market products. This work helps to improve environmental condition of industrial enterprises through decontamination of toxic liquid waste, as well as to facilitate the rational use of water and energy.