Experimental Research On Treatment Of Electroplating Copper And Nickel Wastewater By Ion Exchange Process

Nowadays most industries are involved in electroplating,and the discharge of electroplating wastewater is increasing.In order to protect the ecological environment and human health,this part of wastewater must be effectively treated.The traditional treatment method of electroplating wastewater has high energy consumption and the electroplating sludge produced easily causes secondary pollution.Therefore,it is imperative to develop an efficient treatment technology for electroplating wastewater.In this study,ion exchange method was used to treat electroplating wastewater,different types of ion exchange resins were screened,and the static and dynamic treatment effects of the selected resins were investigated to achieve harmless treatment of electroplating wastewater.The treatment capacity of 732,CH-90 and D001 resins for copper and nickel ions in electroplating wastewater was investigated,and the exchange capacity,adsorption exchange rate and regeneration performance were selected as indicators.Finally,D001 resin was selected as the preferred resin.At an initial p H of 6,the reaction of D001 resin with copper and nickel ions reached equilibrium at 120 minutes,and the exchange capacities of the two ions were 52.19 mg / g and 58.18 mg / g,respectively.Regeneration of D001 resin after exchange saturation,the regeneration efficiencies of copper and nickel ions were 85% and 91%,respectively.Using scanning electron microscopy and X-ray energy spectroscopy to characterize and analyze the resin,the surface morphology of D001 resin before and after the reaction changed significantly,and after the reaction,it already had copper and nickel elements.In the static test,the effects of resin dosage,reaction time,initial concentration and temperature,interfering ions on the resin’s static adsorption of copper and nickel ions are analyzed,and the reaction mechanism is explored.As the resin dosage decreases,the reaction time increases,and the exchange capacity shows an upward trend.The increase of initial concentration and temperature is conducive to the increase of exchange capacity,and when the initial concentration is higher,the effect of temperature increase on exchange capacity is more significant.When there are a small amount of interfering ions in the system,there will be no significant interference to the adsorption of copper and nickel ions by the resin.The reaction process of D001 resin with copper and nickel ions conforms to the Langmuir isotherm adsorption model and quasi-first-order kinetic model.The theoretical maximum single-layer ion exchange capacities of the two ions under 25℃ are 89.42 mg /g and 92.91 mg / g.A fixed-bed resin column was used for ion exchange dynamic exchange and desorption regeneration experiments to study the effects of resin dosage,inlet water flow rate and inlet water concentration on the resin’s dynamic adsorption of copper and nickel ions.The results show that the dynamic exchange capacity increases when the resin dosage increases,and the dynamic exchange capacity decreases when the inlet water flow rate and inlet water concentration increase.The dynamic penetration model is used to fit the experimental data.The BDST model can predict the penetration time and the depletion time when the inlet condition changes.The Yoon-Nelson model can fit the 50% concentration penetration time of the resin column and the corresponding penetration Predict through the curve.The Na Cl solution was used as the regeneration fluid for the dynamic regeneration test.The test results showed that the regeneration effect increased with the increase of the regeneration agent concentration and decreased with the increase of the regeneration flow rate.Comparing the regeneration effect of the regenerated liquid prepared with deionized water and tap water,the results show that the regenerated liquid prepared with deionized water is more effective.This article uses ion exchange to achieve the effective removal of copper and nickel ions,providing theoretical basis and technical support for the standard discharge of electroplating wastewater in actual production.