The process of copper regeneration from spent hydrochloric acid etching solution of printed circuit boards is considered. A combined scheme is proposed, which includes the preliminary removal of excess chlorine ions from the solution, using a highly basic anion exchange resin and the subsequent electrochemical precipitation of copper. A solution contents, g/dm3: 237 Cu, 27 NH4Cl, 11.6 HCl was used. Electrical extraction was performed at a current density of 650 A/m2. The method makes it possible to prevent the emission of chlorine at the anode and ensures the obtaining copper as metal.

The use of hydrogen peroxide and hydrazine sulfate for the treatment of chrome-containing rinsing waters of galvanic production of machine-building enterprises is proposed. The process of reducing chromium (6+) to (3+) from rinsing waters with a concentration of 8.55 mg/dm3 was studied. These reagents allow reducing more than 99% of chromium (6+) to chromium (3+) and maintaining a low salt content of treated wastewater. The consumption of hydrogen peroxide is 1.5 mg/dm3, and the consumption of hydrazine sulfate is 10 mg/dm3. The current situation in the treatment of galvanic wastewater leads to pollution of the environment with dangerous substances (CN-, Cr6+, F-, Cd2+), irrational use of raw materials and significant economic losses. The possibility of extracting valuable components from wastewater, in order to recycle them and return the treated water to production, is considered. Hydrogen peroxide is effective for treating acidic wastewater, and hydrazine sulfate can be used for both acidic and alkaline wastewater. Removal of excess hydrogen peroxide from the solution after reduction of chromium (6+) before precipitation of chromium (3+) hydroxide is required. The toxicity of hydrazine compounds must be taken into account.

The article substantiates the necessity of using modern materials and technologies for purifying industrial wastewater, because the problem of processing waste products of galvanic production of machine-building enterprises is very important. The current situation in this area leads to environmental pollution by hazardous substances (CN–, Cr6+, F–, Cd2+), irrational use of raw materials and significant economic losses. Investigation of ways out of it is an urgent task. The results of a study of water supply and wastewater treatment problems are analyzed, i.e. the authors analyze the processing of technological solutions and wastewater, emphasizing the possibility of extracting valuable components and returning purified water to production. The authors propose to use hydrogen peroxide and hydrazine as a reagent for the extraction of metals at low salinity process water. An integrated approach to the analysis of the use of reagents, materials and technologies of wastewater treatment of industrial enterprises is proposed.

In this article, the necessity of integrated approach to the analysis and solution of problems of safety of water supply and wastewater treatment are declared. The results of the study the main problems of the systems of production of water supply and wastewater treatment are described. Practical measures for solving problems are proposed. Pressing need of application of means of informatization, strategic risk analysis methods and innovative technologies of water treatment are declared. The basic principles of safe and effective critical systems of water supply and wastewater treatment in the sphere of production are proposed.