Removal Of The Cu²⁺ And Cr⁶⁺ In The Mine Waste Water By Using The Nanoscale Zero-valent Iron Supported On Activated Carbon

The copper and chromium?VI?are the common heavy metal pollutants,for the human body's metabolism and growth and development of plants and animals,they both are the essential elements,but when its content exceeds a certain value,they will bring the life great threat.Therefore,the pollution of copper and chromium?VI?'s control has had to be a wake-up call for mankind.In recent years,the nZVI has been widely studied and applied in the treatment of organic pollutants and heavy metals pollution areas.The nZVI has a large surface area,high surface energy,high activity characteristics,it has a great advantage for the removal of pollutants,but because of its easy to oxidation and easy aggregation result in decreased reaction activity.A large number of studies have found that:when the nZVI load on the carrier,it can reduce the aggregation,improve the nZVI's removal efficiency.The main purpose of this paper is to research the nZVI loaded on the GAC,and use it to remove aqueous Cu²⁺ and Cr⁶⁺ reaction conditions and reaction mechanism,and use the SEM,specific surface area and pore size analysis and X-ray photoelectron spectroscopy?XPS?reaction materials,to verify the feasibility.Using different materials for the reaction solution to remove the Cu²⁺ test,in which the RAC is the best,and when the iron content of 10.99%,the RAC dosage of15 mg / L,the reaction pH = 5,the reaction time 24 h,an initial concentration of Cu2 +50mg / L,the removal rate of the reaction was 85.06%.Increase the RAC can clog pores but lower removal;the RAC the more removed the better;removal greatly affected by the pH value at pH = 2 to pH = 7 of inter,after removal of the first to reduce the rise;as the reaction proceeds,the removal rate is increasing;little effect on the removal of the initial concentration of the test.Reaction mechanism of RAC removal reaction of Cu2 + mainly the RAC reduction,followed by re-activated carbon adsorption of copper ions,the nZVI the form of ferric existence after the reaction,and copper ions and places Cu0 and Cu2 O form.And using the RAC to remove the Cr⁶⁺,when using 15 mg / L the RAC,at pH = 5,reaction temperature is 25?,and the initial concentration is 20 mg / L and reaction time was 12 h,removal rate reached 97.57%.The reaction products were analyzed by XPS analysis showed that the activated carbon supported the RAC removal ofhexavalent chromium ion reaction is mainly nZVI on copper ion reduction and the RAC adsorption,reaction after nZVI is oxidized in the presence of Fe2O3 and the FeOOH forms of Fe3+,and Cr6 + is was reduced to Cr?OH?3 exists in the form of Cr3+.