Study On The Enhancement Of The Stability And Nitrogen Removal Efficiency Of Klebsiella Sp.-Entrapped Chitosan Beads

This study expands the idea and method of denitrification,and provides some data reference for this technology.A new Klebsiella sp.strain was selected and cultured in the laboratory,This simultaneous nitrification and denitrification bacteria were used as object of research,and chitosan was used as carrier to immobilize it to produce immobilized chitosan beads(KSND-Chitosan,KSND-CH),and its immobilization effect and performance were characterized.The cell growth activity,stability,nitrogen removal efficiency and repeated batch recycling effect under different factors were studied,and the effect of immobilized bacteria on organic was further investigated Finally,it was used in the integrated purification equipment to investigate the practical application effect of immobilized KSND-CH.The results showed that the morphology of immobilized KSND-CH was uniform and spherical,and KSND bacteria was embedded in chitosan spheres,and the immobilization process had no effect on the activity of bacteria.The results show that chitosan carrier can improve the denitrification effect of KSND bacteria under different p H conditions,and the protection effect of KSND-CH is better under acid conditions;In the wastewater containing Cu²⁺?Co²⁺?Mn²⁺?Fe²⁺?Zn²⁺,the denitrification efficiency of immobilized KSND-CH pellets is 67%,78%,87%,57%,66%,respectively.The denitrification efficiency of wastewater containing aniline,methanol,formaldehyde,phenol and carbon tetrachloride is 91%,87%,26%,81%and 77%respectively.Compared with the denitrification efficiency of free bacteria,the denitrification efficiency of chitosan carrier can help bacteria resist the influence of adverse environment.The immobilized KSND-CH can be reused,and the maximum degradation rate of ammonia nitrogen is 97%and 86%respectively.The effect of immobilized KSND-CH in wastewater denitrification treatment is significantly better than that of sponge packing KSND bacteria or free KSND bacteria.The maximum degradation rate of ammonia nitrogen can reach98%,and it can maintain more than 90%of the degradation rate for a long time in 15 days.The application of immobilized KSND-CH in the integrated sewage treatment equipment shows that the denitrification efficiency can be maintained at 100%in the later stage of the test process,and the nitrogen element in the sewage can be completely removed.In conclusion,the application of immobilized KSND bacteria in biological denitrification of domestic sewage has great advantages and prospects.