Research For Enrichment Of Heavy Metals Wastewater With Electrodialysis's Method

This paper studies the reuse of heavy metal pollution at home and abroad,in order to achieve a low concentration of heavy metals in waste water discharge standards and heavy metal ions.This method has the advantages of easy to produce secondary pollution,the enrichment of metal ions and easily recycled,operating conditions can be flexibly controlled.This method can achieve the discharge of heavy metals in waste water treatment.The experiment for the copper ion concentration is from 10 to 50mg/L wastewater study.According to the experimental requirements,designed a electrodialysis device.Control in the comparative experiments performed under different conditions.The following conclusions:(1)The experimental DC voltage from 2V to 10V,the experimental results show that the DC voltage greater impact the concentrated electrodialysis concentrate effect,as the voltage is increased,the concentration efficiency rose from 36.6%to 90.4%.As the DC voltage increases,the power consumption is also increased,identified by 6V to 8V DC voltage for optimum voltage conditions.(2)Under the conditions of suitable operating conditions,the experiment for the energization time of electrodialysis concentrate heavy metals,in the DC voltage of 6V,serials running the experiment 5 hours.Experimental results show that the energization time of the electrodialysis concentrate heavy metals in certain substantially trend with the growth of the energization time.The Desalination chamber effluent concentration gradually becomes lower,up to a concentration of 1.89-4.59mg/L.The concentration chamber effluent can up from 49.87 to 70.11 mg/L,the concentration efficiency is achieve from 83.45%to 93.17%.(3)ln the experimental plate spacing efficiency of electrodialysis concentrated impact plate spacing for the single factor variable experiment.In the experiments of this section,the DC voltage is 8V,the plate spacing from 160mm to 360mm,each plate spacing increase to 40mm.Desalination chamber effluent concentrations from 3.308mg/L to 4.996 mg/L,the concentration chamber effluent concentrations up to 92.54 mg/L,the efficiency reach from 87.63%to 91.82%.The experimental results show that as the plate spacing decreases,the ef:ficiency of electrodialysis concentrate gradually reduced.(4)Removing the film bubble measures can significantly improve the efficiency of the electrodialysis concentrate dilute,mainly to remove the film bubble increases the effective area of the electrodialysis ion exchange membrane,then enabling the desalination was concentrated efficiency.(5)The anode chamber as electrodialysis conduct will progressively lower the pH to about 6.0.When using stainless steel as the anode material,the phenomenon of corrosion will occur,and the anode chamber has generated a large number of iron hydroxide precipitate.Corrosion of the anode plate holes formed zonal distribution.Show that the solution is formed inside the laminar flow,the physical and chemical properties of the layers are diffirent,and there fore lead to corrosion of the anode plate position zonal distribution.(6)When the voltage is applied in concentrated chamber change concentrated Interior ion migration direction,causes the film surface to the vicinity of the ion layer is reduced.When the electrodialysis mixture in low concentrations,can cause a short room desalination efficiency decreases.When the the electrodialysis liquid at higher concentrations,this approach has little effect on the desalination efficiency.Mainly because of the limited reduction of the result of this measure in a high concentration near the membrane ionic layer does not affect the rate of membrane ion migration to the concentrated chamber.