Partial nitritation of nitrogen-rich refinery wastewater (sour water) with different Ci/N molar ratios

Abstract

AbstractIn this study, a SHARON reactor was used to treat synthetic and real ammonium-rich refinery wastewater (sour water) with different inorganic carbon to nitrogen (Ci/N) molar ratios, in order to evaluate its possible implementation downstream of a steam stripping unit in a double-stage SHARON–ANAMMOX or SHARON–heterotrophic denitritation process. A synthetic influent containing -N (2,000 mg/L) was initially fed to promote biomass acclimation, and then real sour water containing also organic substrate, cyanides, sulphides and phenols was supplied. With both synthetic and real wastewater, the applied Ci/N molar ratio was progressively increased from 1 to 2 and the SHARON reactor produced an effluent suitable for further treatment by autotrophic ANAMMOX or heterotrophic denitritation, respectively. Acute toxicity assessments based on the specific measurement of nitritation activity confirmed that biomass acclimation to the toxic substances contained in the real wastewater occurred successfully. Moreove...