Application of voltage to enrich anaerobic ammonium-oxidizing bacteria from mixed cultures for the degradation of actual wastewater containing COD
摘要
Anaerobic ammonium-oxidizing bacteria (AnAOB) present significant enrichment challenges due to slow growth kinetics and extended cultivation periods. This study employed single-chamber microbial electrolysis cells (MECs) to investigate substrate conversion rates, microbial community dynamics, and bacterial morphological adaptations in mixed consortia (incorporating nitrifiers, denitrifiers, and AnAOB) under varying applied voltages (0–1.2 V). Key results demonstrated that at 0.6 V, ammonium removal efficiency nearly doubled compared to the 0 V baseline, with AnAOB relative abundance increasing from 5.78 ± 0.38% to 12.34 ± 0.60% while denitrifiers decreased from 9.69 ± 1.33% to 2.84 ± 0.14%. Voltage escalation to 1.2 V induced proliferation of denitrifiers, which coexisted with AnAOB under carbon-limited conditions. During actual wastewater operation, ammonium degradation rates declined to 73% (Cycle 1) and 68% (Cycle 2), yet AnAOB maintained functional dominance at 12.56 ± 0.40% relative abundance. These findings provide valuable insights for AnAOB enrichment from complex communities, demonstrating voltage optimization’s potential to enhance syntrophic interactions and intensify nitrogen removal pathways.