PENGXing-yuan,XIAOYue-bing,ZHENGMeng-qi,et al.Calcium Peroxide Enhanced Nitrogen Removal Efficiency of Excess Sludge Pyrolytic Liquid[J].China Water & Wastewater,2024,40(3):31-37.
Calcium Peroxide Enhanced Nitrogen Removal Efficiency of Excess Sludge Pyrolytic Liquid
China Water & Wastewater[ISSN:1000-4062/CN:12-1073/TU]
volume:
第40卷
Number:
第3期
Page:
31-37
Column:
Date of publication:
2024-02-01
- Keywords:
- sludge pyrolysis; calcium peroxide; sludge dewatering performance; nitrogen removal efficiency
- Abstract:
- The excess sludge is rich in organic matter, easy to cause secondary pollution and has high treatment cost, so it is necessary to explore the method of its resource recovery. In this study, calcium peroxide (CaO2) combined with pyrolysis was employed to treat excess sludge to enhance biological nitrogen removal. Compared with the pyrolysis treatment of excess sludge, the total chemical oxygen demand (TCOD) in the pyrolysis liquid from the combined process increased by 11.3%, the denitrification rate and nitrogen removal efficiency increased by 59.5% and 19.6%, respectively, and the sludge capillary suction time (CST) decreased by 33.7%. The results of single factor experiment showed that the addition of oxidant had no obvious improvement on the composition and nitrogen removal efficiency of the sludge pyrolytic liquid, the addition of alkali increased the TCOD of the pyrolytic liquid by approximately 3 times, and the addition of flocculent calcium increased the ratio of soluble COD (SCOD) to TCOD of the pyrolytic liquid by 25.3% and decreased the CST of the sludge by 72.0%. In summary, the mechanism of calcium peroxide enhanced nitrogen removal efficiency was that the calcium flocculation removed the macromolecular inert substances in the excess sludge, thereby increasing the proportion of biodegradable carbon sources in the pyrolytic liquid.
Last Update:
2024-02-01