Hydrodynamic cavitation effects over complex organic mixtures

Abstract

Hydrodynamic cavitation (HC) is a promising technology for the intensification ofchemical and physical processes, with applications in wastewater treatment, extractionfrom suspended solids, and disinfection. In this study, the effects of HC on differentmodel compounds for dissolved organic matter (DOM) were investigated. Thesecompounds, such as lignin, humic acids, and protein-like compounds, are commonlypresent in organic wastewaters and were studied under various conditions.Specifically, changes in UV-Vis spectra and fluorescence properties resulting from HCtreatments were analyzed. Results show that HC had distinct effects on the spectralindices, fluorescence intensity, and peak positions of the model compounds. Changesin humic acid and lignin were attributed to the oxidation and fragmentation of polymers,while changes in tryptone were explained by the polymerization and partial oxidation ofits amino acids. Pyrolysis was found to be the dominant mechanism affecting non-polarsubstances, such as zwitterions in tryptone, whereas radical attack predominantlyaffects hydrophilic compounds like large, charged molecules like humic acids. Largemolecules with both charged and non-charged groups, such as lignin, experienced amixed effect. Findings in this work provide a comprehensive understanding of HCeffects on various DOM model compounds. These results could aid in the developmentof more efficient HC-based treatment processes for organic pollutants.