Intensification of anaerobic digestion efficiency with use of mechanical excess sludge disintegration in the context of increased energy production in wastewater treatment plants

Abstract

Abstract. The main goal of the study was to evaluate the effects of mechanical sludge disintegration for enhancing full scale anaerobic digestion of municipal sludge. Batch disintegration tests and lab dewatering tests were also performed aiming at determining the release of organic compounds and assessing the impact of disintegration of excess sludge before the fermentation process of mixed sludge on the dewaterability of post-fermented sludge, respectively. In the study a disc disintegrator driven by a motor with a power of 30 kW, revolutions n = 2950 rpm has been used. It was shown that with increase of energy consumed in the disintegration, the increased amounts of organic compounds were released from the sludge. It was also documented that the introduction of the excess sludge disintegration prior to fermentation tank, resulted in a significant increase in biogas production (by an average of 33.9%) and in increase in volatile total solids reduction in the fermented sludge (by an average of 22.7%). Moreover, the obtained results indicate the possibility of obtaining a higher degree of sludge dewatering, which was subjected to anaerobic stabilization with using disintegrated excess sludge.

Achieving energy neutrality in wastewater treatment plants through energy savings and enhancing renewable energy production

“…Also new applications of hydrodynamic cavitation are beginning to emerge in other fields such as enhancing biogas production from WAS (Dular et al 2016). -Sudoł et al (2017) showed that with the increase in energy consumed in disintegration, the increased amounts of organic compounds were released from the sludge. It was also documented that the introduction of WAS disintegration prior to the fermentation tank, resulted in 33.9% increase in the biogas production (Moss et al 2013).…”

Entrained Flow Plasma Gasification of Sewage Sludge–Proof-of-Concept and Fate of Inorganics

“…The possibility of biological activity in sewage sludge must be considered when it is used. As a result, a great deal of study has been done on sewage sludge deactivation and stabilisation [3][4][5][6][7][8] through many different thermal utilisation routes: thermal hydrolysis [9], hydrothermal carbonisation (HTC) [10][11][12], HTC integrated with anaerobic digestion [13,14], torrefaction [15,16], pelletising [17], pyrolysis and co-pyrolysis [18,19], gasification [20][21][22][23], and combustion [24].…”

Cascade Membrane System for Separation of Water and Organics from Liquid By-Products of HTC of the Agricultural Digestate—Evaluation of Performance

“…Moreover, dewatering effluent's storage inevitably leads to water loss through evaporation, which nowadays is becoming an increasingly scarce resource in the agriculture sector during climate change [17][18][19][20]. Additionally, digestate still contains significant amounts of recalcitrant organic matter [21], which prompted many investigations regarding increasing its availability for further digestion to produce additional amounts of biogas [22][23][24][25][26]. Furthermore, nowadays higienisation of digestate or removal of ammonia is also considered as important issues [27,28].…”