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Influence of salinity on partial nitrification in a submerged biofilter
1Cumhuriyet University, Department of Environmental Engineering, 58140 Sivas, Turkey. saslan@cumhuriyet.edu.tr
Bioresource Technology
|June 15, 2012
Summary
Partial nitrification in submerged biofilters shows optimal performance without salt. Low salt concentrations (1 g/l NaCl) slightly enhance ammonium removal, but higher salinity inhibits the process significantly.
Area of Science:
- Environmental microbiology
- Wastewater treatment engineering
Background:
- Partial nitrification is a key process in biological nutrient removal.
- Salinity is a critical factor affecting microbial activity in wastewater treatment.
Purpose of the Study:
- To investigate the impact of varying sodium chloride (NaCl) concentrations on partial nitrification performance.
- To determine the optimal salinity range for efficient ammonium removal in submerged biofilters.
Main Methods:
- Utilized a submerged biofilter reactor operating under constant conditions.
- Applied a range of NaCl concentrations from 0 to 40 g/l.
- Monitored nitrogen loading rates (NLR) and surface loading rates (SLR).
Main Results:
- The highest nitrite-to-nitrate ratio (NO(2)-N/NO(x)-N) of 0.76 was achieved in salt-free wastewater at an NLR of 830 g NH(4)-N/m(3) day.
- Ammonium removal efficiency increased from 92% to 95% at 1 g/l NaCl.
- Higher NaCl concentrations (above 1 g/l) led to significant inhibition of ammonium oxidation.
Conclusions:
- Partial nitrification is sensitive to salinity, with optimal performance observed in freshwater conditions.
- Low salinity may offer a slight benefit, but high salt concentrations severely impair the process.
- Wastewater salinity must be considered for effective partial nitrification and nitrogen removal.
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