Biological Nitrogen Removal Database
A manually curated data resource for microbial nitrogen removal
Biological Nitrogen Removal Database
A manually curated data resource for microbial nitrogen removal
Influent:Synthetic wastewater
Denitrification system:Anoxic sulfide-oxidizing (ASO)
Denitrifying reactor:Up-flow biomass retention
Medium:nan
Culture taken from:Anaerobic methanogenic sludge
Organism (s) cultured:nan
Respiration:Anaerobic
Electron donor:Sulphide
Electron acceptor:Nitrite
Input NO3-N (mg/l):18
Nitrate removal rate (mg NO3-N/l/h):17.4
Denitrification rate (gNO3-N removed/m3/day):nan
Microorganisms identified:nan
Molecular tools:nan
Major findings:The Anoxic sulfide-oxidizing (ASO) reactor implemented in this study achieved high influent concentrations and short HRT, suggesting that it can be used to treat concentrated wastewaters containing nitrite and sulfide simultaneously within a short period of time saving operational cost.
Authors:Mahmood et al., 2007
Title:Anoxic Sulfide Biooxidation Using Nitrite as Electron Acceptor
Pubmed link:Link
Full research link:Link
Abstract:Biotechnology can be used to assess the well being of ecosystems, transform pollutants into benign substances, generate biodegradable materials from renewable sources, and develop environmentally safe manufacturing and disposal processes. Simultaneous elimination of sulfide and nitrite from synthetic wastewaters was investigated using a bioreactor. A laboratory scale anoxic sulfide-oxidizing (ASO) reactor was operated for 135 days to evaluate the potential for volumetric loading rates, effect of hydraulic retention time (HRT) and substrate concentration on the process performance. The maximal sulfide and nitrite removal rates were achieved to be 13.82 and 16.311 kg/(m3 day), respectively, at 0.10 day HRT. The process can endure high sulfide concentrations, as the sulfide removal percentage always remained higher than 88.97% with influent concentration up to 1920 mg/L. Incomplete sulfide oxidation took place due to lower consumed nitrite to sulfide ratios of 0.93. It also tolerated high nitrite concentration up to 2265.25 mg/L. The potential achieved by decreasing HRT at fixed substrate concentration is higher than that by increasing substrate concentration at fixed HRT. The process can bear short HRT of 0.10 day but careful operation is needed. Nitrite conversion was more sensitive to HRT than sulfide conversion when HRT was decreased from 1.50 to 0.08 day. Stoichiometric analyses and results of batch experiments show that major part of sulfide (89–90%) was reduced by nitrite while some autooxidation (10–11%) was resulted from presence of small quantities of dissolved oxygen in the influent wastewater. There was ammonia amassing in considerably high amounts in the bioreactor when the influent nitrite concentration reached above 2265.25 mg/L. High ammonia concentrations (200–550 mg/L) in the bioreactor contributed towards the overall inhibition of the process. Present biotechnology exhibits practical value with a high potential for simultaneous removal of nitrite and sulfide from concentrated wastewaters at shorter HRT.