Trattamenti di ossidazione avanzata di macro e microinquinanti organici contenuti nelle acque reflue per consentire il riuso dell’acqua.

Water pollution has been a persistent environmental concern, driving extensive research into effective wastewater treatment methods. Among the advanced oxidation processes (AOPs), cavitation-based treatments have emerged as promising technologies due to their high efficiency in pollutant removal. The objective of this doctoral research focuses on the degradation of dyes, hydrocarbons, and phenols from industrial wastewater, particularly from the textile, pharmaceutical, and agro-industries. Hydrodynamic cavitation (HC) has shown significant potential in treating dyeing solutions, even at low concentrations, and achieving the mineralization of organic pollutants. The study investigates the degradation of Methyl Blue (MB) using HC and evaluates the effectiveness of a hybrid process combining ozone (O3) with HC. Optimal operating conditions were determined, including pressure (4.5 bar), pH (2), and O3 dosage (7.5 mg/L). Results showed that the hybrid process significantly enhances degradation efficiency, achieving a 100% decolorization yield for MB at an initial concentration of 10 mg/L within 30 minutes. Additionally, the research explores the treatment of winery wastewater (WW) using the Fenton process, which demonstrated up to 85% COD removal under optimal conditions (pH 3, [H2O2] = 0.5 mol/L, [H2O2]/[Fe2+] = 2.5) within 1 hour. The integration of membrane processes with HC and Fenton treatment for dyeing wastewater was also examined, highlighting the potential for water reuse and safe discharge of treated effluents. The research investigates the removal of polycyclic aromatic hydrocarbons (PAHs) from soil washing emulsions using Fenton and solar photo-Fenton processes, emphasizing the recovery and reuse of surfactants. Soil was artificially contaminated with anthracene (ANT) and benzo[a]pyrene (BaP) and subsequently washed using sodium dodecyl sulfate (SDS). Complete removal of PAHs was achieved with the Fenton process, with BaP consistently degraded across all conditions, while ANT required the highest H2O2 (240 mg dm⁻³) and Fe (10 mg dm⁻³) concentrations over 6 hours. The solar photo-Fenton process achieved 100% removal of BaP and up to 70% removal of ANT. Notably, minimal SDS degradation and negligible emulsion mineralization were observed, indicating preservation of the surfactant’s integrity post-treatment. This study presents a comparative analysis of traditional wastewater treatment processes and innovative approaches incorporating hydrodynamic cavitation. The findings reveal substantial improvements in pollutant removal efficiencies and cost-effectiveness. Notably, the innovative process achieved a 95% reduction in COD, underscoring the efficacy of the combined operation. Significant enhancements in TOC and BOD5 reductions further highlight the potential of these methods to produce high-quality effluent suitable for industrial reuse. Additionally, the process analysis of the Takeda wastewater treatment plant demonstrated the effectiveness of integrating hydrodynamic cavitation with advanced oxidation processes. The plant's comprehensive multi-stage process, A detailed cost analysis further supports the economic feasibility of these innovative treatment methods. In conclusion, this thesis underscores the potential of hydrodynamic cavitation and its combination with other advanced processes as sustainable and effective wastewater treatment technologies. The findings contribute to advancing knowledge in the field and provide valuable insights for developing innovative remediation strategies. Keywords: Hydrodynamic cavitation, Advanced oxidation processes, Wastewater treatment, Methyl Blue, Ozone, Fenton process, Winery wastewater, Textile industry, Polycyclic aromatic hydrocarbons, Soil remediation, Surfactant Recovery