Endogenous Influences On Anammox And Denitrification Coupling System And Dynamic Operating Strategy

The possibility of fast startup of anammox reactor through dosage of Fe²⁺ was explored through the experiment.The anammox sludge was cultured to integrate anaerobic ammonia oxidation?anammox?and sulfocompound-oxidizing autotrophic denitrification coupling system?A/SAD?.The results showed that the anammox reactor with 0.09 mM Fe²⁺ first completed the startup period.The anammox culture with 0.09 mM Fe²⁺ also had the maximal sludge activity,with the value of 1.03 g-N L-1 d-1.The results of mechanism analysis indicated that the anammox reactor with 0.09 mM Fe²⁺ had the highest Heme C concentration and HDH enzyme activity,which may be related to the fastup of anammox reactor.The?A/SAD?was initiated in an expanded granular sludge bed?EGSB?reactor for nitrogen removal from high-strength wastewater.Owing to cooperation between anammox and partial sulfocompound-oxidation autotrophic denitrification coupling system?PSAD?,the highest nitrogen removal efficiency?NRE?of 98.1%± 0.4%achieved at the optimal influent conditions of conversion efficiency of ammonium?CEA?of 55%and S2O32--S/NO3--N?S/N?of 1.4 mol mol-1.The activity of the short-cut sulfocompound-oxidizing autotrophic denitrification?SSAD?was also regulated to cope with dynamic CEA in the influent by changing the S/N,which was demonstrated to be effective in alleviating nitrite accumulation when the CEA was between 57%?61%.Both the anammox and SAD bacteria enriched in the reactor after long-term incubation.Candidatus Brocadia and Candidatus Jettenia might be potentially contributing the most to anammox,while the Thiobacillus was the dominant taxa related to SAD.Anammox and hybrid-denitrificaiton coupling system was initiated through mixing of A/SAD and heterotrophic denitrification.When COD was between 50?100 mg L-1,NRE over 93.0%was achieved when the reacotor performance was stable.It was a effective strategy to regulate S/N coping with the dynamic CEA of influent when the influent CEA was between 57%and 63%.