Work

Performance stability of partial nitritation/anammox process in treating food waste digestate: NOB inhibition and microbial interactions

Year: 2026

Type: article

Abstract: Disruption of microbial community stability induced by organic matter presents key challenges in applying the anammox process to treat food waste digestion (FWD). In this study, the proliferation of nitrite-oxidizing bacteria (NOB) led to the collapse of the partial nitritation/anammox (PN/A) process, resulting in a reduction of nitrogen removal efficiency (NRE) to 21.6% in the treatment of FWD. Treatment with in-situ free ammonia (15–20 mg/L) and ex-situ free nitrite acid (10 μg/L) slightly inhibited the activity of NOB during the first 8 days. However, NOB rapidly exhibited adaptive tolerance to the two types inhibition, accompanied by a decrease in anammox activity. qPCR results confirm that the decrease in ammonia-oxidizing bacteria (AnAOB) and the increase in denitrifying bacteria (DB) are another key factors influencing the stability of PN/A process. The anaerobic cultivation mode induced inhibition of NOB, with the abundance of Nitrospira decreasing to 0.09%. Simultaneously, AnAOB underwent significant species evolution: Ca . Brocadia increased from 0.15% to 5.76%, leading to enhanced AnAOB (including Ca . Kuenenia ) utilization of NO 2 − -N. This study provides valuable insights into overcoming the challenges associated with NOB and heterotrophic bacterial proliferation during FWD treatment in the PN/A process.

Source: Journal of Water Process Engineering

DOI: 10.1016/j.jwpe.2026.109727