Kuenenia-enriched hydroxyapatite granules enable stable high-rate nitrogen removal of high-strength food waste permeate in an EGSB-anammox system: Insights into granule performance and process scalability
Lan Lin, Wenzhao Zhao, Shen Cui, Ying Song, Yuanfan Zhang, Yu‐You Li
Abstract
Instability and low-efficiency in real wastewater treatment under high-load conditions are bottlenecks in the application of anammox-based technologies. To address the issues, this study investigated an EGSB-anammox-hydroxyapatite (HAP) granular sludge system for the treatment of high-strength permeate (1334–4875 mg N/L) from an AnMBR reactor processing food waste. Spanning 382 days of operation, the EGSB reactor achieved a remarkable escalation in NLRs from 1.2 to 15.4 kg N/m 3 /d, accompanied by a concurrent rise in NREs from 81.1 % to 88.7 %. The incorporation of HAP within the granular sludge system was crucial for enhancing biomass retention and fostering the growth of nitrogen-metabolizing bacteria. Notably, the abundance of Candidatus Kuenenia increased from 36.1 % to 57.1 % as the NLRs escalated, contributing to a theoretical peak nitrogen removal capacity of 38.2 kg N/m 3 /d. These findings validate the feasibility of the anammox-HAP granular system for treating high-strength nitrogenous wastewater, and highlight its potential as a scalable and sustainable alternative for industrial applications.