Microbial community analysis of simultaneous ammonium removal and Fe3+ reduction at different influent ammonium concentrations

摘要

This study investigates the impacts of influent ammonium concentrations on the microbial community in immobilized heterotrophic ammonium removal system. Klebsiella sp. FC61, the immobilized species, has the ability to perform simultaneous ammonium removal and Fe3+ reduction. It was found that average ammonium removal rate decreased from 0.308 to 0.157 mg/L/h, as the influent NH4+-N was reduced from 20 to 10 mg/L. Meanwhile, at a total Fe3+ concentration of 20 mg/L, the average Fe3+ reduction removal efficiency and rate decreased from 44.61% and 0.18 mg/L/h, to 27.10% and 0.11 mg/L/h, respectively. High-throughput sequencing was used to observe microbial communities in bioreactor Samples B1, B2, and B3, after exposure to different influent NH4+-N conditions. Results show that higher influent NH4+-N concentrations increased microbial richness and diversity and that Klebsiella sp. FC61 play a functional role in the simultaneous removal of NH4+-N and Fe3+ reduction in bioreactor systems.