Experimental Study On ANAMMOX Coupled Partial Denitrification

Anaerobic ammonium oxidation?ANAMMOX?process has a unique advantage in the simultaneous treatment of high ammonia nitrogen?NH₄⁺-N?and low carbon nitrogen or carbon free wastewater,But in the process of actual operation of ANAMMOX process,the source of nitrite nitrogen?NO₂^--N?,and after the reaction product of nitrate nitrogen?NO₃^--N?increased effluent concentration of total nitrogen,have hindered the process applied to engineering.The ANAMMOX AUASB reactor was operated with low substrate nitrogen,and achieving ANAMMOX coupled multi-spescies reactor,the high-throughput DNA sequencing technology showed that analysis of the abundance distribution of newly formed multi-spescies.By adding organic carbon source,the ANAMMOX sequencing batch reactor?ASBR?inoculated with AUASB sludge achieved partial denitrification.Then the distribution of bacteria on the surface of ANAMMOX granular sludge in ASBR was analyzed by SEM diagram.Secondly,the nitrogen removal of ANAMMOX coupled with partial denitrification was investigated under different substrate conditions,and the optimum operating parameters of ASBR were determined.Finally,when ANAMMOX and partial denitrification bacteria were stored in different organic matter environments,the decay of their activity was recorded,the main conclusions are as follows:?1?The ANAMMOX AUASB reactor was operated with low DO and gradually reduced nitrite nitrogen,on the 57th day,the removal rate of ammonia was higher than 85%,the high-throughput DNA sequencing technology showed that the Candidatus kuenenia was the main genera with the abundance of 8.85%,the abundance of AOB Nitrosomonas 1.48%,the partial denitrification bacteria Thauera0.66%.The changes of EPS in ANAMMOX aggregates,the change of PN content is relatively slow and the range of change of PS content is more obvious.?2?The SEM observation of ANAMMOX aggregates surface is larger after low concentration NO₂^--N operation,Interwoven adhesion of ANAMMOX and filamentous bacteria to particle surface.Sludge in ASBR with long time and high Organic concentration,The SEM results indicated that the ANAMMOX bacteria were mostly spherical and partial denitrification bacteria were short rod coexist,the whole aggregates maintained a relatively complete form.?3?Batch test found that when inorganic carbon concentration is controlled at2.00 g/L and 2.50 g/L,and ANAMMOX serum bottle was operated with the anoxic-reoxygenation alternately in the reactor,AOB degraded NH₄⁺-N rapidly,and the accumulation of NO₂^--N above 12.0 mg/L can be realized.Under the same pH,when the carbon source concentration is 2.50 g/L,AOB active than carbon source is2.0 g/L,and in the process of reaction when pH increased to 8.5 above,the ANAMMOX bacteria also can maintain higher nitrogen transformation ability.?4?By adding organic carbon source,the ANAMMOX ASBR inoculated with AUASB sludge achieved partial denitrification,then,the nitrite nitrogen accumulation and nitrogen conversion characteristics in the partial denitrification process under different C?N?mass ratio?,The results showed that when C?N was 3.2?1.0,the highest nitrite nitrogen accumulation rate is 84%,but partial nitrite nitrogen was reduced,but by ANAMMOX can limit the reaction of denitrification.?5?The results showed that the partial denitrification bacteria adaptability to changes in pH is better than the ANAMMOX bacteria,when pH was 7.8,the activity of ANAMMOX bacteria was the highest,and removal rate of ammonia was 95%.The low temperature will influence the activity of the partial denitrification bacteria and ANAMMOX bacteria,but at low temperature range partial denitrification bacteria activity stronger than the ANAMMOX bacteria.?6?In NH₄⁺-N increased from 27.8 mg/L to 75.0 mg/L,and the COD concentration increased from 108.0 mg/L to 405.0 mg/L,the reactor for NH₄⁺-N removal rate stay at 100%,the study found that run the ASBR reactor control parameters as follows:In the concentration of NH₄⁺-N is 27.8 mg/L,the operation of ASBR can control the substrate nitrogen concentration of NH₄⁺-N and NO₃^--N concentration ratio is1,COD and NO₃^--N concentration ratio was 3.1±0.1.in the concentration of NH₄⁺-N is 46.7 mg/L and 75.0 mg/L,the operation of ASBR can control the substrate nitrogen concentration of NH₄⁺-N and NO₃^--N concentration ratio is 1.5±0.1,COD and NO₃^--N concentration ratio was 3.2±0.1.?7?The success of the laboratory culture of ANAMMOX coupled partial denitrification bacteria can make use of glucose and sucrose,when the sludge is domesticated by glucose and sucrose,it is more beneficial to the enrichment of specific partial denitrification bacteria.When acclimated with glucose for 7 days,the removal rate of NH₄⁺-N increased from 5.7%to 43.8%,and the highest NO₂^--N accumulation is 5.6 mg/L.?8?When using sodium acetate as organic carbon source for preservation,the replacement of denitrification bacteria occurred in ANAMMOX coupled partial denitrification bacteriae,on the 12th day,the ability of partial denitrification was loss in preservation of bottles,but denitrification occurred,on the 16th day,the removal rate of NH₄⁺-N is 15.2%.When using glucose,The activity of partial denitrification bacteriae and ANAMMOX bacteria was detected to decay steadily within the controllable range,on the 16th day,the removal rate of NH₄⁺-N is 34.2%,combined with the appearance of the preservation of sludge color change,analysis of glucose as organic carbon source is more advantageous to preserve ANAMMOX coupled partial denitrification bacteria.