Study On Denitrification Efficiency And Characteristics Of Sludge Flora Of ANAMMOX Granular Sludge With Different Particle Sizes

As a new type of nitrogen removal technology,anaerobic ammonium oxidation has the advantages of saving aeration energy,saving carbon source,reducing sludge production and greenhouse gas emissions,and is suitable for treating high ammonia nitrogen wastewater with low C/N ratio.The mature anaerobic ammonium oxide granular sludge has good sedimentation performance,high treatment load and high practical value.The study of the properties of anaerobic ammonium oxide granular sludge and rapid culture method are beneficial to the promotion of anaerobic ammonium oxidation technology.In this paper,the properties of anaerobic ammonium oxide granules with different particle sizes were compared.The characteristics of anaerobic ammonium oxide granules with different particle sizes were analyzed.The concentration of metal ions and low concentration organic carbon sources were increased.The molecular flocculant CPAM was studied to promote the particle size growth of anaerobic ammonium oxide granular sludge.The main conclusions are as follows:?1?Anaerobic ammonium oxidation The physical and chemical properties of the granular sludge are related to the particle size of the granular sludge.The sedimentation performance,specific density and biomass content of the sludge are positively correlated with the particle size of the granular sludge,and the larger the particle size of the granular sludge,the smaller the inorganic ion content and the larger the proportion of organic components.The R4 granular sludge has the largest particle size,the best anaerobic ammonium oxidation activity,and the best performance in resisting impact load.In general,large particles have outstanding anaerobic ammonium oxidation performance and high practical value.?2?With the growth of anaerobic ammonium oxide granular sludge,the EPS content continues to increase,and the increase of PN content is the most prominent,and the change of PS content is rare.The PN content increased from 43.4 mg/g VSS for R1 to 95.1 mg/g VSS for R4,and PN/PS increased from 5.29 for R1 to 8.12 for R4.The increase of PN content in EPS affects the hydrophobicity and zeta potential of sludge,which promotes the aggregation of anaerobic ammonium oxide granular sludge and accelerates the growth of its particle size.?3?With the increase of particle size of granular sludge,the microbial community is continuously succeeding,the microbial diversity is decreasing,but the abundance of anaerobic ammonia bacteria is increasing,and the functional capacity of granular sludge is enhanced.The anammox bacteria in the sludge are mainly from the genus Candidatus Kuenenia.The growth of granular sludge also makes the synergy between the various strains closer,mutual benefit and symbiotic competition,and together maintain a relatively stable ecosystem.The functional abundance of microorganisms in large granular sludge is continuously improved in three aspects:the growth and metabolism activity of a microorganism is improved;the second genetic information can be accurately translated and translated;and the signal transmission between three organisms is more frequent.Both ensure the biological activity and biostability of large particle anaerobic ammonium oxidation sludge.?4?Ca²⁺,Mg²⁺and Fe³⁺can promote the growth of R1 granular sludge,and Ca²⁺promotes the growth of granular sludge most obviously,but with the increase of dosage,the biomass and anaerobic of granular sludge Oxygen ammoxidation activity has decreased.The addition of Mg²⁺had the least effect on the particle size growth of anaerobic ammonium oxide granular sludge,but the cultured granular sludge showed the best performance in biomass and anammox activity.The performance of adding Fe³⁺cultured anaerobic ammonium oxide granular sludge is between Ca²⁺and Mg²⁺,but Fe³⁺is inseparable from the proliferation of anammox bacteria.The optimum concentration of Ca²⁺,Mg²⁺and Fe³⁺to promote the growth of granular sludge was0.08mmol/L,0.04 mmol/L and 0.06 mmol/L.The average growth rate of continuous growth for 90 days was 6.11?m/d,4.67?m/d,5.22?m/d.?5?Appropriate addition of organic carbon source can make the heterotrophic bacteria in the culture bottle compete with the anaerobic ammonia bacteria,so that the anaerobic ammonia bacteria secrete a large amount of EPS to protect their own growth environment,and the EPS is beneficial to the bacteria.Adhesion accelerates the growth of anaerobic ammonium oxide granular sludge.Increasing the EPS content and PN/PS of anaerobic ammonium oxide granular sludge,the average growth rate of granular sludge was 5.57?m/d and 6.0?m/d when the concentration of organic carbon source was 50mg/L and 80mg/L,respectively.Higher than the blank control flask.When the concentration of added organic matter is higher than 130 mg/L,the anaerobic ammonium oxidation activity is inhibited,and the granular sludge grows slowly.When the applied organic matter concentration is higher than 190 mg/L,the anaerobic ammonium oxide granular sludge begins to disintegrate.?6?The addition of 25-40 mg/L of CPAM can increase the anaerobic ammonium oxidation activity of the granular sludge.The concentration of CPAM is over 50 mg/L,and the anaerobic ammonium oxidation activity of the granular sludge is inhibited.After adding 25mg/L and 35mg/L CPAM to continuously culture R1 particle size anaerobic ammonium oxidation sludge for 70d,the average growth rate of granular sludge was 5.21?m/d and 5.43?m/d,respectively,which were higher than the blank control group..The addition of CPAM can accelerate the growth of anaerobic ammonium oxide granular sludge,but the cultivated granular sludge is weakened in mechanical strength.