Study On The Impact Of Organic Matter Concentration On Nitrogen Removal Performance And Eps Features Of CANON By Activated Sludge Process

Compared with the traditional biological denitrification process,completely autotrophic nitrogen removal over nitrite(CANON)can reduce about 63% oxygen,100% savings plus carbon source,to a great extent,reduces the cost of biological denitrification treatment,biological denitrification for wastewater treatment research provides a new way of thinking.Single-stage autotrophic denitrification process by autotrophic Bacteria Anammonium Oxidation Bacteria(AOB)and Anaerobic Ammonia Oxidation Bacteria(AAOB)will be completed Ammonia into nitrogen denitrification process,the whole operation process does not need to consume organic carbon source.Containing no organic carbon source,however,the actual wastewater is almost non-existent,so we need to study the nitrogen removal performance of completely autotrophic nitrogen removal over nitrite with organic matter concentration.This study used Sequencing Batch reactor(SBR),explored the start-up and performance of completely autotrophic nitrogen removal over nitrite;After a period of stable operation of completely autotrophic nitrogen removal over nitrite,by adding organic carbon source(glucose)to study the nitrogen removal performance and through the species identification to discuss the change of the microbial flora of the system under the condition of different C/N;Studied the component content changes of extracellular polymeric substances(EPS)during the process of adding organic matter.Using common activated sludge as the inoculation sludge in the SBR reactor,First,using synthetic wastewater completed part of the nitrosation,and then vaccinated a few biofilm sludge which are taken from the SBBR reactor(it successfully completed the start-up and performance of completely autotrophic nitrogen removal over nitrite under the same condition with the SBR reactor),after 131 days' operation the system of completely autotrophic nitrogen removal over nitrite was successfully launched in the SBR reactor.Then the total nitrogen removal rate reached 60.43%.And by increasing concentration of ammonia nitrogen to increase the volume of ammonia nitrogen load,Finally,the total nitrogen removal rate reached to 76%,the total nitrogen removal load got 0.35 kgN/(m3· d).The advantagebacterium are Candidatus Anammoxoglobus bacteria genera which belong to the Planctomycetes and Nitrosomonas which belong to the ?-Proteobacteria type in the system of of completely autotrophic nitrogen removal over nitriteUsing the CANON system,which has been training well and stable operation,by increasing the concentration of organic carbon source(glucose)and keep the concentration of ammonia constant,make the average COD/NH4+-N of the inflow increased.Results show that under the condition of COD/NH4+-N less than or equal to 0.7,The synergy between betanaerobic ammonia oxidation bacteria and heterotrophic denitrifying bacteria can raise the TN removal rate of the system,when the COD/NH4+-N ratio was increased to 0.7,the ammonia nitrogen removal rate and TN removal rate are 91.98% and 84.39% respectively;Under the condition of COD/NH4+-N = 0.9,the system of anaerobic ammonia oxidation bacteria lose competitive advantage with the heterotrophic denitrifying bacteria,which reduced the TN removal rate decreased and the unstable poperation of the system.The result of the species identification showed: adding organic carbon source in 26 d days,the denitrifying bacteria Thauera(soxhlet bacteria genera)become the dominant species,but the abundance of Candidatus Anammoxoglobus and Nitrosomonas reduced in the system.Taking three different methods to extract extracellular polymers,by comparing the amount of extracellular polymer and cell breakage under different methods found that heat extraction to extract with high efficiency and less DNA relative content,so that heat extraction method was regarded as the effective extraction method in the system.With the average ratio of C/N increasing from 0 to 0.9,the content of EPS increased before it was reduced;The content of extracellular polysaccharides and DNA increased gradually but protein content gradually reduced,TB-EPS has a little impact on the coagulation sedimentation performance of sludge.