Performance analysis of iron-carbon autotrophic denitrification for efficient removal of nitrate from anammox effluent
The investigation of nitrate removal from anammox effluent using the iron-carbon autotrophic denitrification process,involved the examination of continuous operation,iron precipitation transformation,and microbial community structure.The study revealed the coupling mechanism between the iron-carbon carrier and biofilm,demonstrating the efficient removal of nitrate through the iron-carbon autotrophic denitrification process.At HRT of 16.6h,the total nitrogen(TN)removal efficiency of anammox effluent was found to be(90.0±4.7)%.Conversely,the TN removal rate of anammox effluent was(82.2±1.4)%at HRT of 13.3h.During Stage Ⅰ,Fe3O4 was identified as the predominant form of iron precipitation within the biofilm,whereas in Stage Ⅲ,there was a decrease in Fe3O4 and an increase in the density of FeOOH type iron precipitation.Throughout the iron-carbon autotrophic denitrification process,the prevalence of Dechloromonas,the primary denitrifying bacterium in the initial sludge inoculum,experienced a notable decrease.Conversely,there was an enrichment of autotrophic denitrifying bacteria and iron-converting bacteria,exemplified by the rise in relative abundance of Thermomonas from 0.70%on day 43 to 4.51%on day 120.
iron-carbon carrierbiofilmautotrophic denitrificationiron precipitationmicrobial community