Effect Of Water Cycle And Carrier Modification On The Removal Of Ammonia/Manganese In Groundwater By Composite Manganese Oxide

In our country,groundwater is the main source of water supply in many areas,but in some areas,the concentration of manganese and ammonia nitrogen in groundwater is too high and needs to be dealt with urgently.The previous research of the research group found that by reacting Fe Cl₂ and Mn Cl₂ with KMn O₄ to form a composite iron-manganese oxide,a composite iron-manganese oxide film can be formed on the surface of the quartz sand,and ammonia nitrogen and manganese can be simultaneously removed.However,at present,the loading of iron-manganese composite oxide on quartz sand in the circulating system and how to increase the load strength of the iron-manganese composite oxide have not been studied in depth.This experiment examines the difference in the removal of ammonia nitrogen and manganese by the iron-manganese-iron-manganese composite oxide loaded with quartz sand in the water circulation system and the non-circulating system,and the difference and load of the removal of ammonia nitrogen and manganese by the modification of quartz sand and the iron-manganese composite oxide loaded on different carriers.Intensity explores whether there is a difference between the circulation system and the method of enhancing the load intensity,including the following three aspects:1)the influence of water circulation on the catalytic oxidation of ammonia nitrogen/manganese by the composite manganese oxide;2)the modified quartz sand loading iron manganese Research on the removal of ammonia nitrogen and manganese by composite oxides in groundwater;3)Research on the removal of ammonia nitrogen/manganese by iron-manganese composite oxides loaded on different carriers;The main results and conclusions of the paper are as follows:（1）In the early stage of the system operation,compared with the circulating water regular renewal system,the circulating water continuous renewal system and the non-circulating system have a better removal rate of ammonia.This is because the circulating water continuous renewal system and the non-circulating system in this stage The filter media oxide film has a smaller crystal size,which can provide more surface adsorption potential,resulting in a faster rate of effective removal of ammonia.After stopping dosing of potassium permanganate,the circulating water regularly updates the system to have a good removal rate of manganese.This is because after the system stops dosing potassium permanganate,in order to prevent the concentration of manganese in the circulating water from exceeding the standard,the manganese dosing method It is changed to be added regularly every day,and the circulating water is regularly updated at this stage,and the system has a good load strength for the composite manganese oxide.（2）When the filter material in the circulating water system and the non-circulating system is actually used to remove ammonia and manganese,as the filter material in different systems matures,the structure of the oxide film in different systems tends to be the same,and the circulating water is regularly updated.The filter media in the non-circulating system can effectively remove ammonia and manganese.（3）The specific surface areas of iron ion-modified quartz sand,hydrophobically modified quartz sand and unmodified quartz sand are 2.437 m²/g,2.325 m²/g,0.328 m²/g.have a larger specific surface area.In the aqueous solution of pH 8,the Zeta potentials of the iron ion modified quartz sand,hydrophobically modified quartz sand and unmodified quartz sand are 0.41mv,18.32mv and-23.31mv respectively,indicating that the surface of modified quartz sand is more conducive to Adsorption of complex manganese oxides.The modified quartz sand oxide film has lower crystallinity and smaller crystal size,so it can provide more surface adsorption sites.Therefore,more complex manganese oxides are adsorbed on the surface of modified quartz sand and have better loading strength,and have better removal effect and stability for ammonia and manganese.（4）In the aqueous solution with pH 8,the Zeta potentials of the initial quartz sand,initial magnetite,and initial manganese sand are-23.31mv,-14.38mv,-16.62mv,respectively,and the Zeta potential of the modified quartz sand surface is even higher.Close to 0,so magnetite and manganese sand are more conducive to the adsorption of composite manganese oxides,and have better loading strength for composite manganese oxides,so they have better removal effects for ammonia and manganese.As the filter material matures,the surface of the carrier is covered with composite manganese oxide,and the surface properties of different carriers tend to be the same.Therefore,after the filter material matures,the membrane growth of different carriers tends to be the same.