ABSTRACT
The rapid growth in the variety and quantity of contaminants of emerging concern (CEC) in wastewater indicates the necessity for developing efficient and environmentally friendly methods for their removal. This study investigates the removal efficiency of 46 CEC, including 12 bisphenols, from wastewater using a lab and pilot-scale hydrodynamic cavitation generator alone and in combination with UV illumination (pilot-scale). During lab-scale cavitation, the highest removal efficiencies of bisphenols (15-63%) for this specific design of cavitator were obtained at a rotational frequency (vcav)â¯=â¯9500â¯rpm and time (tcav)â¯=â¯10â¯min. Temperature and the physicochemical properties (e.g. Kow) of the studied compounds also had a significant effect on removal efficiency. At the pilot-scale, 11 CECs were quantifiable in the wastewater influent, and the generator operated at νcavâ¯=â¯2290 and 2700â¯rpm. The highest removal efficiencies (15-90%) were obtained at a lower νcavâ¯=â¯2290â¯rpm while neither an increase in νcav, tcav or the presence of UV-C light increased the removal efficiency. A lower νcav also reduced the hydrodynamic power of the cavitator from 477â¯W to 377â¯W, resulting in reduced energy consumption. Overall, the results show the potential of hydrodynamic cavitation for a large-scale application as a pre-treatment technology and pave the way for future improvements in the design of cavitation reactors.