@misc{10481/83644,
year = {2023},
month = {7},
url = {https://hdl.handle.net/10481/83644},
abstract = {Two-stage partial nitritation (PN) and anammox (AMX) systems showed promising results for applying auto-trophic nitrogen removal under mainstream conditions. In this study, a pilot-scale (600 L per reactor) two-stage PN/AMX system was installed in a municipal wastewater treatment plant (WWTP) provided with a high-rate activated sludge (HRAS) system for organic carbon removal. The PN/AMX system was operated without tem-perature control (ranging from 11 to 28 degrees C) and was subjected to the same variations in wastewater charac-teristics as the WWTP (22 to 63 mg NH4+- N/L). The developed strategy is simple, does not require the addition of chemicals and is characterised by short start-up periods. The PN process was established by applying a high hydraulic load and maintained by in situ accumulated free nitrous acid (FNA) of 0.015-0.2 mg HNO2-N/L. Based on pH value, a controlled aeration strategy was applied to achieve the target nitrite to ammonium ratio in the effluent (1.1 g NO2--N/g NH4+-N) to feed the AMX reactor. Although NOB were not fully washed out from the system, nitrite accumulation remained (>99 %) stable with no evidence of NOB activity. In the AMX reactor, an overall nitrogen removal efficiency of 80 % was achieved. Regarding effluent quality, 12 +/- 3 mg TN/L was obtained, but 5 mg NO3--N/L was already in the HRAS effluent. The relative abundance of NOB showed a strong negative correlation with the FNA concentration, providing a good strategy for establishing PN under main-stream conditions.},
organization = {European Commission (EU) through the LIFE project ZERO WASTE WATER
	LIFE19 ENV/ES/000631},
organization = {Waterworks 2014 Cofounded Call (Water JPI/Horizon) through the Pioneer_STP (MINECO (AEI)/(UE))
	ED481B-2021-041},
organization = {Spanish Government (AEI)
	199,
	
	CTM2014-55397-JIN,
	
	CTQ2017-83225-C2-1-R,
	
	PID2020-112550RB-C21},
organization = {Xunta de Galicia
	PID2020-112550RB-C22},
organization = {PCIN-2015-022},
publisher = {Elsevier},
keywords = {Ammonium oxidising bacteria (AOB)},
keywords = {Anammox},
keywords = {Municipal wastewater treatment},
keywords = {Nitrite oxidising bacteria (NOB) suppression},
keywords = {PN/AMX pilot plant},
title = {Rapid start-up and stable maintenance of the mainstream nitritation process based on the accumulation of free nitrous acid in a pilot-scale two-stage nitritation-anammox system},
doi = {10.1016/j.seppur.2023.123851},
author = {Pedrouso, Alba and Rodelas González, María Belén and Correa Galeote, David},
}