The article discusses the chemical methods of cleaning the engineering enterprises drains. It was shown that chromium-containing effluents are neutralized by restoring highly toxic hexavalent chromium to less toxic trivalent in an acidic medium, followed by sedimentation and release of Cr(OH)3 as a precipitate at pH = 8.5-9.5.
In this study, the purification of industrial effluents from heavy metal ions was carried out by using the example of wastewater from electroplating industry of the Valve Plant (Ust-Kamenogorsk) using a sorption method with a nanostructured complex sorbent based on opal-quartz-carbonate clay of horizon 11 and mineral wool production wastes.
It has been established that, for chromium and zinc ions, a change in the pH of the wastewater solu- tions has virtually no effect on high and effective purification, which further allows for the purification of galvanic effluents without subsequent solution neutralization. For iron and copper ions, an increase in the pH of the solutions leads to an increase in sorption from 70.88% to 85.23% and from 73.42% to 86.08%, respectively.
Keywords: purification, neutralization, wastewater of electroplating production, sorption, heavy metal ions.
