Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
4482867 | Water Research | 2012 | 7 Pages |
Aerobic granular sludge from a lab-scale reactor with simultaneous nitrification/denitrification and enhanced biological phosphorus removal processes exhibited significant amount of ammonium adsorption (1.5 mg NH4+–N/g TSS at an ammonium concentration of 30 mg N/L). Potassium release accompanied ammonium adsorption, indicating an ion exchange process. The existence of potassium magnesium phosphate (K-struvite) as one of potassium sources in the granular sludge was studied by X-ray diffraction analysis (XRD). Artificially prepared K-struvite was indeed shown to adsorb ammonium. Alginate-like exopolysaccharides were isolated and their inducement for struvite formation was investigated as well. Potassium magnesium phosphate proved to be a major factor for ammonium adsorption on the granular sludge. Struvites (potassium/ammonium magnesium phosphate) accumulate in aerobic granular sludge due to inducing of precipitation by alginate-like exopolysaccharides.
► Potassium magnesium phosphate (K-struvite) accumulated in aerobic granular sludge. ► K-struvite was found to be a potassium source for ion exchange with ammonium. ► The formation of struvites is induced by alginate-like exopolysaccharides.