Energy-Positive Disintegration of Waste Activated Sludge—Full Scale Study

Energies

Monika Zubrowska-Sudol¹  Katarzyna Sytek-Szmeichel¹  Agnieszka Bisak¹  Piotr Krawczyk² 

[1] Faculty of Building Services, Hydro and Environmental Engineering, Warsaw University of Technology, Nowowiejska 20, 00-653 Warsaw, Poland;Faculty of Power and Aeronautical Engineering, Warsaw University of Technology, Nowowiejska 24, 00-655 Warsaw, Poland;

关键词: anaerobic digestion;    mechanical disintegration;    waste activated sludge;    biogas production;   

DOI  :  10.3390/en15020555

来源: DOAJ

【 摘 要 】

This study aimed to evaluate the effects of mechanical disintegration of waste activated sludge (WAS) on full scale anaerobic digestion, considering the possibility of obtaining a positive energy balance. The results showed that an increase in energy density (ε_L) used in disintegration was accompanied by an increase in the release of organic compounds from sludge (SCOD increased from 211 ± 125 mg O₂/L for ε_L = 0 kJ/L to 6292 ± 2860 mgO₂/L for ε_L = 180 kJ/L). Some of them were volatile fatty acids. The percentage share of WAS subject to disintegration was also documented as a crucial parameter affecting the efficiency of biogas production. An increase in the value of this parameter from 25% to 100%, even at much lower ε_L used in disintegration (therefore with much smaller amounts of organic compounds released from sludge flocs) resulted in an increase in biogas production. Conducting disintegration of the entire stream of WAS directed to the fermentation tank at ε_L 30 kJ/L resulted in an increase in biogas production by 14.1%. Such a surplus would allow production of approximately 360 kWh/d net electricity. Mechanical disintegration of thickened WAS therefore may be an economically justifiable strategy for the intensification of anaerobic sludge stabilisation.

【 授权许可】

Unknown