Fast startup of one-stage nitritation-anammox reactor for high-rate nitrogen removal from mature landfill leachate

Abstract

Fast startup of one-stage partial nitritation (PN)-anaerobic ammonium oxidation (ANAMMOX) process for the treatment of nitrogenous wastewater is still a challenge that remains to be solved In this study, rapid establishment of one-stage PN-ANAMMOX column reactor inoculated with the mixture of dispersed biomass from a partial nitritation (PN) reactor and granular biomass from an ANAMMOX reactor was investigated. Excellent reactor performance was shown during adaptation first to synthetic inorganic wastewater and thereafter to mature landfill leachate. Combining online pH and DO monitoring for ensuring a stable pH level and oxygen limitation was the key to maintaining stable reactor performance. Nitrogen removal up to 1.7 kg N m–3 d–1 from raw mature landfill leachate was eventually obtained, indicating the effectiveness in the operational strategy on high rate and efficient nitrogen removal from landfill leachate via one-stage PN-ANAMMOX process. Nitrogen mass balance analysis indicates that ANAMMOX and heterotrophic denitrification contributed to 78.7% and 20.7% of the nitrogen removal, respectively