Study On Influencing Factors And Activity Recovery Of Ammonia Nitrogen/Manganese Removal By Catalytic Oxidation

The research of this group found that the oxides formed by the use of potassium permanganate,ferrous oxide and manganese chloride can effectively remove ammonia nitrogen and manganese pollutants in water.In this paper,the effects of different ions（HCO₃^-,NO₃^-）on the catalytic oxidation of ammonia nitrogen and manganese by the composite oxide film were studied.At the same time,different recovery methods were used to recover the inactive filter materials.The following results and conclusions have been achieved:（1）The addition of 10 mg/L NO₃^--N inhibited the transformation of NO₂^--N to NO3-N,and the peak value of NO₂^--N accumulation was 0.52 mg/L.In the stable operation stage when the addition of 10 mg/L NO₃^--N was stopped,the operation time required for the removal rate of manganese by the active filter material to reach 90%was 32 days.Therefore,the addition of 10 mg/L nitrate in the film hanging stage inhibited the removal of manganese by the active filter material.With the continuous operation of the filter column to the later stage,the manganese removal effect of the filter column is the same as that of the blank filter column.（2）The addition of 100 mg/L alkalinity to the influent during the film forming process improved the catalytic oxidation activity of the filter material and the ability of the active oxidation film to remove ammonia nitrogen pollution.The results show that the removal efficiency of manganese was affected by the filtration rate by adding nitrate during the process of membrane formation.The higher the filtration rate was,the worse the removal efficiency was;In a certain range of filtration rate,the ability of ammonia nitrogen removal was not affected by the filtration rate.The addition of alkalinity during the membrane hanging period made the removal capacity of ammonia nitrogen and manganese not affected by the filtration rate within a certain range of filtration rate,and the removal stability of pollutants by the active membrane is better.（3）The change of alkalinity and pH caused by the addition of HCO₃^-and NO₃^-ions was not the reason for the difference of removal efficiency of manganese pollution.However,the addition of 10 mg/L NO₃^--N in the biofilm stage caused an increase in the concentration of NO₂^--N in the effluent of the filter column,which was related to the poor removal effect of manganese pollution by iron manganese composite oxide filter media in the subsequent nitrate filter column.When 10 mg/L NO₃^--N was added during the film formation,the formed oxide film appeared to harden and had few pores on the surface of the film,which was not conducive to the adsorption and might affect the catalytic oxidation,4.91（?）（18.04°2θ）,3.33（?）（26.79°2θ）.The formation of the peak was not the factor leading to the efficient removal of ammonia nitrogen,that was to say,the main peak leading to the efficient removal of ammonia nitrogen was the characteristic peak of manganese ore,not the characteristic peak of magnesium zinc ore.（4）When the inactivated Fe-Mn composite oxide filter material was used for recovery,there was no accumulation of nitrite nitrogen in the recovery process of natural recovery,alkalinity recovery and recoating.Natural recovery filter and alkalinity recovery filter can remove 1 mg/L ammonia nitrogen pollution in a short time by low concentration recovery.The maximum load of ammonia nitrogen of natural recovery and alkalinity recovery filter column was 2 mg/L,and that of ammonia nitrogen was 1.5mg/L.The results show that the three recovery methods do not change the microstructure of the oxide film on the surface of the filter material,and the crystal structure stability of the Fe-Mn composite oxide was always good.Under different recovery methods,the Fourier spectrum did not change significantly.In terms of economic benefits and removal efficiency,natural recovery is the most suitable.