The Treatment Of Ammonia Nitrogen Wastewater By Three-dimensional Electrode Method

With the progress of human society and the development of industry,the pollution of water resources is increasingly serious,among which ammonia nitrogen pollution is more serious.Ammonia nitrogen not only causes great harm to the ecological environment and human health,but also causes great loss to the economy and society.Three-dimensional electrode is a kind of electrochemical oxidation method,which has the advantages of saving drugs,simple equipment,convenient operation,fast processing speed and less occupation.It is made by filling the two plates of the two-dimensional electrode with a granular material as the third electrode.In this paper,the effects of three-dimensional electrode method on simulated ammonia nitrogen waste water were studied by preparing modified particles.The main contents are as follows:(1)Study of two-dimensional electrode main influence factors include treatment effect of ammonia nitrogen,ammonia nitrogen initial concentration,current density,concentration of chloride ions,p H and plate spacing,through single factor experiment,get the two-dimensional electrode degradation of initial concentration of ammonia nitrogen wastewater ammonia nitrogen to 40 mg/L,current density of 7.5 m A/cm~2,p H value of 4,the chloride ion concentration of 200 mg/L,plate spacing is 1.0 cm,ammonia nitrogen removal rate was 63.28%.(2)The modified particles were prepared by high temperature calcination with impregnation method,and the optimal ratio was determined by orthogonal test.Bentonite content is 20%,calcination temperature is 600 degrees Celsius,Fe/c ratio is 3:1,loading tin and antimony.Through the single-factor test,the modified particles in the micro-electrolysis process,when the p H value is 4,the best treatment effect of ammonia nitrogen,ammonia nitrogen removal rate is 10.99%.SEM scanning electron microscopy(SEM)and EDS energy spectrum(EDS)were used to observe the morphology characteristics and analyze the components of the modified particles,and it was found that the modified particles after calcination had more developed spatial pore structures.The modified particles loaded with tin,antimony and cobalt had the best skeleton structure,followed by the modified particles loaded with tin and antimony,and the modified particles without load had the worst skeleton structure.(3)To explore the three-dimensional electrode are the main factors causing the degradation of ammonia nitrogen wastewater,get when the calcination temperature is600 degrees Celsius of particle electrode,the load of tin and antimony,initial concentration of ammonia nitrogen is 40 mg/L,the chloride ion concentration of 200mg/L,p H value of 4,the current density of 7.5 m A/cm~2,the air of 150 ml/min,adding amount of modified particle electrode is 15 g,three-dimensional electrode method of ammonia nitrogen wastewater treatment effect is best,removal rate of 86.08%.Using SEM scanning electron microscope,it was found that the modified particle electrode had better reuse rate.The kinetic study and the removal mechanism analysis of ammonia nitrogen were carried out,and it was concluded that the reaction of removing ammonia nitrogen by three-dimensional electrode followed the first-order chemical reaction kinetics and the removal mechanism of ammonia nitrogen mainly included direct oxidation and indirect oxidation.By comparing the removal rates of ammonia nitrogen and total nitrogen,it can be concluded that 80%of the ammonia nitrogen in the three-dimensional electrode was oxidized to nitrogen and escaped from the water,some of the ammonia nitrogen was converted to nitrate nitrogen or nitrite nitrogen.