Start-up of low-temperature anammox in UASB from mesophilic yeast factory anaerobic tank inoculum

Abstract

Robust start-up of the anaerobic ammonium oxidation (anammox) process from non-anammox-specific seeding material was achieved by using an inoculation with sludge-treating industrial -, organics- and N-rich yeast factory wastewater. N-rich reject water was treated at 20°C, which is significantly lower than optimum treatment temperature. Increasing the frequency of biomass fluidization (from 1–2 times per day to 4–5 times per day) through feeding the reactor with higher flow rate resulted in an improved total nitrogen removal rate (from 100 to 500 g m⁻³d⁻¹) and increased anammox bacteria activity. As a result of polymerase chain reaction (PCR) tests, uncultured planctomycetes clone 07260064(4)-2-M13-_A01 (GenBank: JX852965) was identified from the biomass taken from the reactor. The presence of anammox bacteria after cultivation in the reactor was confirmed by quantitative PCR (qPCR); an increase in quantity up to ∼2×10⁶ copies g VSS⁻¹ during operation could be seen in qPCR. Statistical modelling of chemical parameters revealed the roles of several optimized parameters needed for a stable process.

Keywords:

• reject water
• fluidization
• Planctomycetes
• deammonification
• AOA

Acknowledgements

This study was supported by research projects IUT20-16, SLOKT11027T, AR12017, SLOKT12222T and SLOKT12034T. Anne Paaver is acknowledged for the analyses of water samples.