Mechanism And Control Factors Of Ammonia Nitrogen Catalytical Oxidation

In this paper,the catalyst GS was made of the catalyst MS by impregnation method.After that,they were used to treat the ammonia nitrogen waste water as the catalyst,while H₂O₂ was used as the oxidant.The experiment was divided into three parts: Firstly,the ammonia nitrogen waste water was oxidized by H₂O₂ alone.Although H₂O₂ has a strong oxidizing ability,it was still not strong enough to achieve the purpose of denitrification.Then,both of the catalysts were used to deal with the waste water.As two common water treatment filter materials,they had an adsorption effect on NH₃/NH₄⁺.The removal rate of ammonia nitrogen can reach 19.86% after the waste water was treated by the catalyst MS.The ammonia nitrogen’s concentration of the waste water was 50 mg/L.After the composite material was modified by KMnO₄,its surface roughness and porosity has increased to a certain degree.Besides,the zeta potential in the distilled water has decreased from-30.4mV to-36.1mV at the same time,which enhanced the adsorption capacity of NH₃/NH₄⁺.After the treatment by the catalyst GS,the removal rate of ammonia nitrogen can reach 30.17%,which was 10% higher than the catalyst MS approximately.Finally,H₂O₂ and the catalysts were both worked on the ammonia nitrogen waste water.H₂O₂ can form hydroxyl radicals（·OH）with stronger oxidation ability than H₂O₂ to oxidize ammonia nitrogen under the catalysis of catalyst MS.The main component of the catalyst MS is MnO₂.When H₂O₂ and the catalyst MS worked together,the ammonia nitrogen removal rate was 45.62%.During the modification process,the Mn2O3 or some other low-priced manganese salts on the surface of the composite were oxidized into MnO₂ by KMnO₄,which means the content of catalytic component had increased.Therefore,the removal rate of ammonia nitrogen increased to 67.75% within 30 min when H₂O₂ and the catalyst GS were both used.What’s more,and the reaction product was most likely to be nitrogen or nitrous oxide（N₂/N₂O）,which do not cause acidification of water.Compared with the catalyst MS,the catalyst GS had a more significant denitrification effect with H₂O₂ to treat the ammonia nitrogen waste water.Then the temperature,initial p H of the reaction,the dosage of the new composite and H₂O₂ were investigated by single factor analysis.The results of the test shows that,the optional process condition was determined as: the reaction temperature was 20 ℃,the initial p H was 9.36,the catalyst GS dosage was 20 g,and the H₂O₂ dosage was 3g/L and H₂O₂ was added by three times.Under this condition,the removal rate of ammonia nitrogen can be67.92% for 100 mL（NH₄）₂SO₄ solution in which the concentration of ammonia nitrogen was 50mg/L.