Study On Ion Transport Process Of Arsenic Acid Wastewater By Electrodialysis

The acid wastewater in the process of nonferrous metallurgy contains high concentrations of arsenic,and toxicity of arsenic was extremely strong,which also caused serious pollution to the environment.Meanwhile,this part of the wastewater also contains a lot of acid and valuable metal ions.The traditional treatment method includes precipitation method,adsorption method,biological method and so on.These methods has the disadvantages of large amount of waste residue,high processing cost and difficult recovery of valuable ions in wastewater.Our work was aimed at the shortcomings of traditional methods and the characteristics of flue gas washing wastewater,so the applicant proposes a new ED processing which is efficient new process for extraction of heavy metal recovery process combined with ultrasonic indirect electrochemical oxidation of arsenic in arsenic oxide.This paper was mainly studied the effect of ultrasound on the ion migration of Arsenic,Copper,Zinc,Cadmium and Sulfate in electrodialysis,and the effect of voltage,concentrations,flow rate variation on ion migration.Finally,the effect of voltage,concentrations and flow rate on the arsenic transport rate was clarified by orthogonal test,which provided the relevant theoretical basis for the follow-up work.The effects of ultrasonic on the ion migration of arsenic,sulfate,zinc,copper and cadmium in arsenic-containing wastewater were studied by ultrasonic and electrodialysis coupling equipment which was designed by ourselves.As the result,ultrasound had a certain effect on the migration rate of ions,but the effect was not obvious,which was related to the way of combination between ultrasound and electrodialysis and the mechanism of ultrasound on the ion transport in electrodialysis.In this work,the effect of different single factor conditions on the migration rate of ions in electrodialysis was studied.Research indicated that under the condition of electrodialysis,the optimal voltage of sulfuric acid solution was 8 V,the concentration was 60 g/L,the temperature was 25 ℃ and the flow rate was 36 m L/min.With the increase of the cycle time,the sulfate in the sulfuric acid solution could be removed to 4g/L.At the same time,the kinetic fitting of the relationship between the ion separation rate and the time under the influence of different factors was obtained,and the corresponding kinetic fitting equation was calculated.For different kinds of ions,the voltage and concentration had silimar effects on the migration rate.To investigate the magnitude of the influence about the voltage,sulfuric acid concentration and flow rate on the ion transport process,a three-factor four-level orthogonal experiment was proposed.When the voltage was 12 V,flow rate was 24 mL/min,and concentration of sulfuric acid was 20 %,the ion migration rate in the electrodialysis process reached the highest point.The influence of flow rate among the three influencing factors was the most obvious,and the effect of sulfuric acid concentration was the second,which is less affected by the voltage.