Adsorption Of Low Concentration Ammonia And Humic Acid By Vermiculite And Palygorskite And Their Regeneration

The pollution of groundwater has become a serious problem which was concerned in recent years.Permeable reactive barrier(PRB)for remediation of groundwater contaminants was concerned,which have the advantage of sustainability and economic practicality.Natural mineral materials have become the ideal materials in the removal of water contaminants because of cheapnesse,accessibility,no secondary pollution.In this paper,in order to remove the low concentration of ammonia nitrogen and low concentration of humic acid of groundwater in Shenyang,vermiculite and polygorskite are selected as active materials and regeneration to repeated use.The main study contents and results are as follows:(1)Adsorption of NH3-N by vermiculite and adsorption of HA by polygorskite and adsorption of NH3-N by polygorskite and adsorption of NH3-N and HA by vermiculite/polygorskite were studied.The results show that vermiculite and polygorskite can be better to remove NH3-N,under the conditions of dynamic adsorption,results show that vermiculite and attapulgite can be better to remove ammonia and humic acid.(2)To remove ammonia and humic acid by electrochemical method on Aluminum metal as the anode,the results show that,under certain conditions,Plate voltage of removing NH3-N was 25V,electrolysis time was 6h,the removal rate can reach 85.5%under neutral conditions.Plate voltage of removing HA was 10V,electrolysis time was 0.5h,the removal rate can reach 95.8%under neutral conditions.(3)The regeneration of vermiculite and attapulgite by electrochemical method on aluminum and titanium adode,The experimental results show that the electrochemical can be used to regenerate the vermiculite and attapulgite,under the voltage 20V,time 5h,regeneration rate of vermiculite was 96.68%,regeneration rate of attapulgite was 165.73%,were characterized by XRD,DTA-TG,FTIR analysis,under electrochemical regeneration ammonia and humic acid change,discuss regeneration mechanism of vermiculite and attapulgite.The mechanism of electrochemical regeneration of vermiculite and attapulgite was discussed by vermiculite and attapulgite and vermiculite and attapulgite of regeneration and changes of ammonia nitrogen and humic acid in process of regeneration.(4)Dynamic adsorption of ammonia on vermiculite and adsorption of humic acid on attapulgite and desorption regeneration by electrochemical method were investigated,It was studied that electrochemical dynamic desorption has effect on regeneration by voltage and electrode spacing,Experimental results show that:the higher the voltage and shorter distance,the higher desorption regeneratiion rate.The above results laid for an important foundation for removal of low concentration of ammonia nitrogen and humic acid by vermiculite and attapulgite as permeable reactive barrier technology in water.