Study On The Synthesis,performance And Mechanism Of Embedded Ferric Tannate In The Removal Of Nitrogen From Wastewater

In recent years,increasing eutrophication of water sets new requirements for wastewater nitrogen removal technology by biological treatment.Among these topics,simultaneous nitrification-denitrification and anaerobic ammonia oxidation are the hotspots of innovative biochemical treatment methods.The purpose of the study was to take advantage of the fine denitrification effect exhibited by the embedded sodium alginate-ferric tannate?SA/TA-Fe?to solve the problems such as long start-up cycle,difficult start-up and the solid-liquid separation problems of iron-nitrate?TA-Fe?materials in the practical application,which was provided a theoretical basis for the development of new technologies for wastewater denitrification.Research indicates:1)SA/TA-Fe was prepared by embedding TA-Fe in SA,which with obvious pore structure.SA/TA-Fe has the ability to adsorb and catalyze NH₄⁺-N and NO₂^--N,which can increase the removal of NH₄⁺-N and NO₂^--N simultaneously.2)The usage of SA solution was 20 g·L^-1,the mass ratio of TA-Fe to SA was 2:1,and the crosslinking time was 12 h.At these conditions,the SA/TA-Fe has the best adsorption and catalytic removal effect on NH₄⁺-N and NO₂^--N.3)The initial pH value of the solution was 6⁷,the ambient temperature was 15?,and the concentration of NH₄⁺-N and NO₂^--N in the solution were 25 mg·L^-1 and 50mg·L^-1,respectively.The adsorption and removal rates of NH₄⁺-N and NO₂^--N remained above 70%and 50%by gel spheres after thermal desorption regeneration and repeated experiments five times.4)The short-range nitrification-denitrification was achieved simultaneously by controlling the DO concentration and C/N ratio of the biofilm reactor.After coupling SA/TA-Fe,the average removal rate of ammonia nitrogen and TN can reach 71.93%and78.55%,and the average removal load was 1.22 kg·?m³·d?^-1 and 1.38 kg·?m³·d?^-1,that is,SA/TA-Fe removes NH₄⁺-N and NO₂^--N through adsorption catalytic ammoxidation,which further improves the removal performance.