Type: article
Abstract: The object of the study.Industrial wastewater and basement waters of the composition, mg/dm 3 : 250-280 Cu; 450-510 Zn; 16-20 Fe; 3.0-3.1 pH.Purification of industrial wastewater and basement waters from copper and zinc consists of two stages: a) synthesis of sulfidizing reagents -sodium polysulfides (Na m S n ) and calcium (CaS p ); b) selective precipitation of copper and zinc sulfides from the volume of solutions.Goal.Due to the presence of a two-stage process, it is advisable to carry out thermodynamic forecasting of the stages of obtaining sulfidizing reagents and chemical precipitation of copper and zinc sulfides from solution in order to minimize the number of installation experiments to optimize the process of purification of industrial wastewater and basement waters from metal impurities.Methods and approaches used.Using the "Reaction Equations" option of the HSC Chemistry program, possible reactions between sulfur and alkalis in the preparation of sulfidizing reagents, depending on the mass ratio of the initial reagents, are calculated.The main results.Using the Purbe diagrams, the regions of existence of copper and zinc sulfides were established, which correspond to the following pH and Eh values: a) Cu 2 S, CuS at pH < 3.2; Eh = +0.3-(-0.5)C; b) Zn(HS) 3-, ZnS at pH < 4.8; Eh = -(0.04-1.24).Thermodynamically predicted optimal parameters of pH and redox potential of the medium, providing quantitative precipitation of copper and zinc sulfides from industrial wastewater and basement waters, have been experimentally confirmed.With a specific sulfur consumption of ~2.0 g/g of copper and ~2.25 g/g of zinc, metal recovery is, %: 99.9 Zn; > 95.0 Cu; ~30.0 Fe.
Source: CyberLeninK (CyberLeninka)
Language: Russian
Subfield: Water Science and Technology
Field: Environmental Science
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W7224140096