Ultrasonic Waste and Sludge Treatment
Biogas is generated from sources, such as municipal organic waste, sewage sludge, muck or manure. Ultrasonication improves the digestibility of such organic material leading to more biogas and less residual sludge.
Biogas is a byproduct of the decomposition of organic matter by anaerobic or aerobic bacteria. It consists primarily of methane, carbon dioxide and hydrogen sulfide. This makes biogas a renewable alternative for fossil fuels, such as natural gas.
Energy prices and chemical and sludge disposal costs, environmental legislation and other interests, such as the reduction of odor emissions require waste treatment plants to improve their processing efficiency. The ultrasonic disintegration of the organic material before digestion improves the biogas production significantly. Along with that sonication improves the dewaterability of the sludge and it reduces the amount of residual sludge to be disposed.
Feedstocks for the production of biogas are mixtures of various aggregated and flocculated substances, fibers, viruses and bacteria, cellulose and other inorganic substances. Food waste, organic industrial and commercial waste, such as fats or vinasse are supplemental feedstocks for mesophilic and thermophilic digesters. Ultrasonic cavitation destructs aggregates and cellular structures. Due to the effect on the on the constituent material structure the sludge can be dewatered more easily. Furthermore, the destruction of the aggregates and cell walls improves the bioavailability of intracellular material to decomposition by bacteria.
4x 4kW power-ultrasound for sludge disintegration
Ultrasonic gisintegration of animal manures before anaerobic digestion improves the biogas yields.
The table below shows typical power requirements for various volume flows. The ultrasonic system is generally integrated inline before feeding to the digester. Alternatively, the organic material can be recirulated from the digester through the ultrasonic system back into the digester. Therefore, the ultrasonication step can be easily retrofitted into existing facilities.
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48kW powerful ultrasonic processor for sludge disintegration
- Increase in biogas yield
- Improved anaerobic decomposition
- Improvement of sedimentation behavior due to degassing and flake disintegration
- Improvement of C/N-ratio for denitrification
- Improvement of surplus sludge thickening
- Improved digestion and dewaterability
- Reduction of the amount of flocculants
- Lower disposal costs due to reduction of residual sludge after digestion
- Reduction of required polymer
- Destruction of filamentous bacteria
We recommend the conduct of pilot scale trials e.g. using 1 to 4kW systems. This will show the general effects and improvement for your particular process stream. We will be glad to discuss your process with you and to recommend further steps.
The UIP6000hdT, a 6000 watts powerful sonicator, with ultrasonic flow cell reactor.
Literature / References
- Antonio-Abdu Sami M. Magomnang and Sergio C. Capareda (2018): Effects of Sequential Sodium Hydroxide Ultrasonication and Hot Water Treatment of Rice Straw and Coconut Shell on Biogas Production. Indian Journal of Science and Technology Vol. 11 (18), 2018. 1-12.
- Yasuo Tanaka (2002): A dual purpose packed-bed reactor for biogas scrubbing and methane-dependent water quality improvement applying to a wastewater treatment system consisting of UASB reactor and trickling filter. Bioresource Technology, Volume 84, Issue 1, 2002. 21-28.
- Pérez-Elvira S, Fdz-Polanco M, Plaza FI, Garralón G, Fdz-Polanco F. (2009): Ultrasound pre-treatment for anaerobic digestion improvement. Water Science Technology 60(6), 2009. 525-32.
- Lisa A. Davies, Andrew Dargue, John R. Dean, Michael E. Deary (2015): Use of 24kHz ultrasound to improve sulfate precipitation from wastewater. Ultrasonics Sonochemistry, Volume 23, 2015.
Frequently Asked Questions
What is Waste and Sludge Treatment for Biogas Production?
Waste and sludge treatment for biogas production involves the anaerobic digestion of organic materials, such as agricultural waste, sewage sludge, and food waste, in controlled environments. During this process, microorganisms break down the organic matter in the absence of oxygen, producing biogas—a mixture primarily composed of methane and carbon dioxide. This biogas can be used as a renewable energy source. The treatment process also results in a nutrient-rich byproduct, known as digestate, which can be used as a fertilizer, enhancing the sustainability of waste management practices.
What is Phosphor Recycling from Sludge?
Phosphor recycling from sludge involves recovering phosphorus, an essential nutrient, from sewage sludge, which is often processed in wastewater treatment plants. Sonication is used in this process by applying high-frequency sound waves to the sludge, which disrupts the cell walls of microorganisms and enhances the release of phosphorus from the organic material. This improves the efficiency of phosphorus recovery, making it more accessible for subsequent extraction and purification, ultimately contributing to the sustainable reuse of phosphorus in agriculture.