International Journal of Science, Engineering and TechnologyAuthors: Rohit Sunil Khedkar, Akshay Chaouhana
Abstract: The rapid industrialization and urbanization worldwide have led to the discharge of complex, bio-refractory organic pollutants into water bodies, posing severe threats to ecosystems and human health. Conventional wastewater treatment methods often fail to achieve complete mineralization of these recalcitrant compounds. Advanced oxidation processes (AOPs) have emerged as powerful technologies capable of generating highly reactive hydroxyl radicals (•OH) for non-selective oxidation of organic pollutants. However, standalone AOPs face challenges including high energy consumption, mass transfer limitations, and incomplete mineralization. This comprehensive review examines the synergistic integration of hydrodynamic cavitation (HC) with AOPs and nanomaterials as a transformative approach for wastewater treatment. The fundamental mechanisms of hydrodynamic cavitation—including the formation, growth, and implosive collapse of cavities generating localized extreme conditions—are systematically analyzed. The review explores HC integration with various AOPs including Fenton, photocatalysis, ozonation, and persulfate activation, highlighting the synergistic effects that enhance •OH production and pollutant degradation kinetics. The role of nanomaterials as catalysts in HC-based hybrid systems is critically evaluated, with emphasis on TiO₂, ZnO, zero-valent iron, carbon-based nanomaterials, and composite catalysts. Key operating parameters including inlet pressure, cavitation number, solution pH, catalyst loading, and reactor geometry are examined for their influence on degradation efficiency. Applications for diverse pollutant classes—dyes, pharmaceuticals, phenolics, pesticides, and emerging contaminants—are comprehensively reviewed. Energy efficiency and cavitational yield analyses provide quantitative comparisons between hybrid and standalone processes. Finally, current challenges, scale-up considerations, and future research directions are discussed, emphasizing the potential of HC-AOP-nanomaterial hybrid systems as sustainable, cost-effective solutions for industrial wastewater treatment.
DOI: https://doi.org/10.5281/zenodo.19060516
