Hydrodynamic cavitation (HC) is emerging as one of the most promising enablers of sustainable wastewater treatment. RAPTECH’s CaviFlow® unit harnesses cavitation to intensify oxidation, mixing, separation, and filtration, achieving higher efficiency with lower energy demand.
Concept and Mechanisms
When cavitation bubbles collapse, they generate localized hotspots with transient extreme conditions — temperatures of a few Kelvin and pressures of hundreds of bar [1]. This environment enhances the decomposition of water and dissolved oxygen forming highly reactive species such as hydroxyl radicals (•OH), which effectively degrade organic pollutants [2]. Beyond radical formation, intensive inline mixing ensures uniform exposure of contaminants, oxidants, and microbial colonies to cavitation. The process also benefits from controlled thermal effects: as water passes repeatedly through cavitation zones, mild bulk heating occurs. This additional temperaturer ise enhances reaction kinetics, oxygen transfer, and overall treatmentefficiency [3].
Applications
Pre-treatment for aeration and biological activity
Booster for oxidative treatments
Enhancer for activated carbon treatment
Support for ceramic membrane filtration (micro-, ultra-, and nanofiltration)
Support in sedimentation and clarification
Advantages
Typical Wastewater Applications
Outlook
CaviFlow® demonstrates how physical and chemical intensification can transform wastewater treatment into a more sustainable, energy-efficient, and cost-effective process. Its combination of radical-driven chemistry, thermal enhancement, advanced filtration support, and superior mixing makes ita practical pathway toward future-proof water treatment solutions and circulareconomy targets.
What do you think? Could hydrodynamic cavitation become a mainstream tool for sustainable wastewater management?
Author: Dr. Ahmad Saylam | RAPTECH Eberswalde GmbH
References
Concept and Mechanisms
When cavitation bubbles collapse, they generate localized hotspots with transient extreme conditions — temperatures of a few Kelvin and pressures of hundreds of bar [1]. This environment enhances the decomposition of water and dissolved oxygen forming highly reactive species such as hydroxyl radicals (•OH), which effectively degrade organic pollutants [2]. Beyond radical formation, intensive inline mixing ensures uniform exposure of contaminants, oxidants, and microbial colonies to cavitation. The process also benefits from controlled thermal effects: as water passes repeatedly through cavitation zones, mild bulk heating occurs. This additional temperaturer ise enhances reaction kinetics, oxygen transfer, and overall treatmentefficiency [3].
Applications
Pre-treatment for aeration and biological activity
- Enhances oxygen transfer and microbial accessibility
- Promotes radical formation from water and dissolved oxygen
- Increases oxidative efficiency even without added chemicals
Booster for oxidative treatments
- Strongly synergizes with ozonation, H₂O₂, and combined advanced oxidation processes
Enhancer for activated carbon treatment
- Reduces fouling, improves adsorption, and extends filter life
Support for ceramic membrane filtration (micro-, ultra-, and nanofiltration)
- Cavitation reduces fouling and concentration polarization on membrane surfaces
- Enhances flux and prolongs membrane lifetime by preventing pore blockage
- Creates strong synergies with robust ceramic membranes such as those developed by Fraunhofer IKTS, extending applicability in demanding wastewater streams [4]
Support in sedimentation and clarification
- Destabilizes colloids, emulsions, and bacterial colonies, improving separation and sludge settling
Advantages
- Energy Efficiency – Lower aeration demand through intensified oxygen transfer
- Oxidative Performance – Boosted removal of micropollutants and trace elements
- Filtration & Membrane Enhancement – Reduced fouling, improved flux, and extended lifetime of activated carbon and ceramic membrane systems
- Sedimentation Assistance – Improved particle destabilization and sludge separation
- Modularity– Easy integration into existing treatment systems
Typical Wastewater Applications
- Municipal wastewater (domestic and greywater)
- Industrial effluents (dye-laden, pharmaceutical, oily waters including FO/HFO)
Outlook
CaviFlow® demonstrates how physical and chemical intensification can transform wastewater treatment into a more sustainable, energy-efficient, and cost-effective process. Its combination of radical-driven chemistry, thermal enhancement, advanced filtration support, and superior mixing makes ita practical pathway toward future-proof water treatment solutions and circulareconomy targets.
What do you think? Could hydrodynamic cavitation become a mainstream tool for sustainable wastewater management?
Author: Dr. Ahmad Saylam | RAPTECH Eberswalde GmbH
References
- Gogate, P. R., & Pandit, A. B. (2005). A review and assessment of hydrodynamic cavitation as a technology for the future. Ultrasonics Sonochemistry, 12(1–2), 21–27
- Jyoti, K. K., & Pandit, A. B. (2004). Ozone and cavitation for water disinfection. Biochemical Engineering Journal, 18(1), 9-19
- Ashokkumar, M. (2011). The characterization of acoustic cavitation bubbles – an overview. Ultrasonics Sonochemistry, 18(4), 864–872
- Cunyu, L., et al. (2024). Ultrasonic-assisted membrane processes for the systematic purification of glycyrrhiza wastewater. Ultrasonics Sonochemistry, 111, 107098
- Bagal, M. V., & Gogate, P. R. (2014). Wastewater treatment using hybrid methods based on cavitation and Fenton chemistry: A review. Ultrasonics Sonochemistry, 21(1), 1–14
- Krause, C., et al. (2019). Ceramic-based membranes for water and wastewater treatment. Colloids and Surfaces A: Physicochemical and Engineering Aspects, 578, 123513
