Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7077061 | Bioresource Technology | 2014 | 8 Pages |
Abstract
Magnesium ammonium phosphate (MAP) method was used to recover orthophosphate (PO43â-P) and ammonium nitrogen (NH4+-N) from the alkaline hydrolysis supernatant of excess sludge. To reduce alkali consumption and decrease the pH of the supernatant, two-stage alkaline hydrolysis process (TSAHP) was designed. The results showed that the release efficiencies of PO43â-P and NH4+-N were 41.96% and 7.78%, respectively, and the pH of the supernatant was below 10.5 under the running conditions with initial pH of 13, volume ratio (sludge dosage/water dosage) of 1.75 in second-stage alkaline hydrolysis reactor, 20Â g/L of sludge concentration in first-stage alkaline hydrolysis reactor. The order of parameters influencing MAP reaction was analyzed and the optimized conditions of MAP reaction were predicted through the response surface methodology. The recovery rates of PO43â-P and NH4+-N were 46.88% and 16.54%, respectively under the optimized conditions of Mg/P of 1.8, pH 9.7 and reaction time of 15Â min.
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Physical Sciences and Engineering
Chemical Engineering
Process Chemistry and Technology
Authors
Wei Bi, Yiyong Li, Yongyou Hu,