Microbial Community Analysis and Effect of nZVI on Autotrophic Denitrification in a Biological Reactor

摘要

This study investigates the influence of dosage of nanoscale zero-valent iron (nZVI) on an immobilized biological autotrophic denitrification reactor. Effects of hydraulic retention time (HRT; 11, 13, and 15 h), initial Fe(II) concentration (10, 20, and 30 mg/L), and dosage of nZVI (2, 4, and 6 mg/L) were analyzed by response surface methodology to determine the effect on denitrification. The highest nitrate removal efficiency of 95% occurred under the following conditions: HRT of 13 h, 21 mg/L Fe(II), and 4 mg/L nZVI. High-throughput sequencing was used to analyze the compositions and structures of the microbial community in the bioreactor at different stages. Addition of nZVI had a significant impact on microbial richness and diversity. In addition, strain CC76 and relevant bacteria were the dominant bacteria for the removal of nitrate in the biological reactor.