Start-up and operation of anammox biofilter in treating low-strength ammonia wastewater prepared by tail water from a municipal wastewater treatment plant

BACKGROUND: Economic technology of advanced nitrogen removal of municipal wastewater is urgently needed. In this study, anammox biofilter (A-BF) as a carbon- and energy-saving advanced nitrogen removal process was tested under the conditions of sewage secondary effluent. RESULTS: The results showed that A-BF could be successfully started up under total nitrogen (TN) of both 25 and 75 mg L-1 within 30 days at 25 degrees C. It achieved a nitrogen removal rate of 0.62 +/- 0.08 kg-N m(-3) d(-1) with nitrogen loading rate of 1.35 kg-N m(-3) d(-1) at TN of 17 mg L-1. The ceramsite bed was conducive to the formation of biofilm and enrichment of functional microorganisms. The volatile suspended solid reached 1.39-7.33 g L-1, in which the abundance of the typical anammox bacteria Candidatus_Brocadia and Candidatus_Kuenenia occupied 0.96-1.35% and 0.29-0.92%, respectively. CONCLUSIONS: Overall, under low TN concentration and high nitrogen load, A-BF could be a candidate technique for advanced nitrogen removal of municipal sewage. (c) 2023 Society of Chemical Industry.

Automated summary

In this study, anammox biofilter (A-BF) was tested as an advanced nitrogen removal process for municipal wastewater. The results showed that A-BF could be successfully started up and achieve a high nitrogen removal rate under low TN concentration and high nitrogen load conditions. The ceramsite bed in the A-BF played a crucial role in the formation of biofilm and enrichment of functional microorganisms.