Influent:Synthetic wastewater
Anammox system:Simultaneous nitrification and denitrification (SND)
Anammox reactor:Sequencing batch reactor (SBR)
Medium:Suspension
Culture taken from:Activated sludge from Municipal Wastewater Treatment Plant
Microorganism cultured:Bacillus subtilis A1
Respiration:Aerobic
Electron donor:Ammonium sulphate
Electron acceptor:Oxygen
PH:7.2–7.5
Ammonia removal rate:3.52 mg L-1 h-1
Nitrate removal rate:nan
Ammonia Removal efficiency (%):58.4±4.3%
Nitrate Removal efficiency (%):nan
Total Nitrogen Removal (%):24.9 ± 4.4%
Carbon Source:Sodium acetate
Final products:Nitrogen, Nitrous oxide
Major findings:The heterotrophic nitrification/aerobic denitrification ability of A1 is approximately twice that of other Bacillus species. An open system inoculated with A1 was employed to treat high-strength urban wastewater and showed potential for industrial application.
Authors:Yang et al., 2011
Title:Isolation and nitrogen removal characteristics of an aerobic heterotrophic nitrifying-denitrifying bacterium, Bacillus subtilis A1
Pubmed link:Link
Full research link:Link
Abstract:Bacterium A1, isolated to enhance nitrogen removal from ammonium-rich wastewater in situ, exhibited an amazing ability to convert ammonium to gaseous nitrogen compounds under fully aerobic conditions, while growing autotrophically or heterotrophically. A1 was identified as Bacillus subtilis by morphological and physiological characteristics, and phylogenetic analysis of its 16S rDNA gene sequence. Nitrogen removal by A1 was analyzed in relation to the ammonium concentration, presence of organic carbon, carbon source, and carbon-to-nitrogen ratio (C/N). The nitrogen balance during 120 h of autotrophic growth in the presence of 104.12±1.27 mg/L NH4+N showed that 20.4±2.7% of NH4+N was removed as gaseous nitrogen compounds, and A1 removed 58.4±4.3% of NH4+N within 60 h of growth in acetate medium at a C/N of 6. A mean ammonium removal rate of 3.52 mg NH4+N/(L h) was achieved in an open wastewater system, indicating great potential of A1 for future full-scale applications.