Treatment of Class III wastewater:
(a) Pickling wastewater treatment:
Adjust the pH value of pickling wastewater to 6-9 with sodium hydroxide solution, and inflate it in air for 2-12 hours. After precipitation removal, the strong acid cation exchange resin is used to adsorb the clarified solution to remove the metal cations, and then the reverse osmosis device is used to concentrate and recover the low salt water. The regeneration solution of strong acid cation exchange resin is delivered to the acid liquor tank, and the concentrated high salt water is treated by the reverse osmosis device. After super coagulation resin and activated carbon adsorption, pH adjustment and flocculation treatment, they are evaporated and concentrated into solids, which become harmless solid impurities. The condensed water is recycled, or the high salt water is treated by ultraviolet photocatalytic oxidation chelate ion exchange resin, so that the COD of wastewater meets the standard requirements. Discharge;
(b) Treatment of cyanide containing wastewater:
The pH value of cyanide containing wastewater shall be controlled between 7 and 10. The anion exchange resin treated by meridians can remove cyanide ions from wastewater. Copper and zinc ions in the wastewater enter the reverse osmosis system after being adsorbed by cation exchange resin. Low salt water is reused, and high salt water is removed by chelating ion exchange resin. Heavy metal ions are evaporated, concentrated and solidified after conditioning and flocculation treatment. The machine body becomes harmless solid impurities, the condensed water is recovered, or the high salt water is treated by chelating ion exchange resin, and COD is directly discharged after reaching the standard through ultraviolet photocatalytic oxidation.
Use 4-6mol/L hydrochloric acid to regenerate the anion exchange resin saturated with complex anions, remove hydrogen cyanide and recover the regeneration solution.
(c) Treatment of mixed wastewater from passivation and electroplating cleaning:
The pH value of the mixed wastewater of passivation and electroplating rinsing is controlled between 0 and 5, and hexavalent chromium ion is removed by anion exchange resin adsorption; Zero discharge of electroplating wastewater The pH value of waste water is adjusted from 5~10 to precipitation, and it is filtered by pressure before entering the acid dissolving tank; Anion exchange uses anion treated resin in clear solution to absorb and remove cyanide ions, and then uses hydrogen type strong acid cation exchange resin to remove metal ions. Secondly, the low salt water is reused through the reverse osmosis system. The high salt water is removed by chelating ion exchange resin, evaporated and concentrated into solid after pH adjustment and flocculation treatment, and becomes harmless solid impurities. The condensed water is recycled, or the high salt water is treated by chelating ion exchange resin and co permeated with the high salt water. D It is directly discharged after the ultraviolet photocatalytic oxidation treatment reaches the standard.
After all the sediments are dissolved in the acid tank, precious metal ions in the wastewater are separated by controlling the pH value of the acid to be between 0 and 3. After the resin column is saturated, it is regenerated with strong acid. After the regeneration solution is concentrated and crystallized, precious metal salt with a purity of more than 95% can be obtained. The adsorption properties of silica resin multi column adsorption system for acid solution of noble metal ions were studied. After the residual heavy metal ions are removed by chelating ion exchange resin, the waste water is evaporated and concentrated into solid and becomes harmless solid impurities by adjusting pH value and flocculation treatment. Condensate can be recycled. The acid liquor of silicon X series resin multi column system can also be treated with chelating ion exchange resin, and the UV photocatalytic oxidation COD can be discharged directly after reaching the standard.
