Operation for nitritation of sludge liquor in a full-scale SBR.
At Sjölunda WWTP, a full-scale SBR for treatment of mesophilic sludge digester liquor has been operated almost a year with stable nitrite accumulation. Only nitritation of the sludge liquor is needed since the oxidized ammonium is denitrified in the first anoxic zone of the high-loaded activated sludge in the main plant. The process strategy was to have an ammonium set-point to end the aeration, a low DO concentration and a low pH set-point. An increase of pH set-point from 6.8 to 7.2 increased loss of alkalinity in the effluent and increased sodium hydroxide dosing. An increase of DO set-point from 1.1 mg O2 L(-1) to 1.3 mg O2 L(-1) markedly increased ammonia reduction rates and only slightly increased nitrate production. Today, an introduction of denitritation in the SBR will be a more cost-effective treatment of sludge liquor at Sjölunda WWTP. However, the choice of operation with only nitritation or nitritation/denitritation in sludge liquor treatment should always include a consideration of chemical costs and treatment capacity of both main plant and side-stream plant.
Gustavsson
D J I
DJ
Malmö Water and Wastewater Works, S-205 80, Malmö, Sweden. david.gustavsson@malmo.se
Nyberg
U
U
la Cour Jansen
J
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D001639:Bicarbonates / Q000737:chemistry; D019149:Bioreactors; D006863:Hydrogen-Ion Concentration; D009573:Nitrites / Q000737:chemistry*; D010084:Oxidation-Reduction; D000644:Quaternary Ammonium Compounds / Q000737:chemistry; D012722:Sewage; D012972:Sodium Hydroxide / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods*
D001639:Bicarbonates; D009573:Nitrites; D000644:Quaternary Ammonium Compounds; D012722:Sewage; D012972:Sodium Hydroxide