Removal of polycyclic aromatic hydrocarbons from wastewater using dual‐mode ultrasound system

Treatment of wastewater using ultrasound systems is gaining increasing interest due to its effectiveness for a wide range of pollutants and no secondary pollutant production. This paper proposes two ultrasound systems operating at different ranges of electrical power and frequency developed to remove toxic polycyclic aromatic hydrocarbon (PAH) compounds in wastewater. Both light molecular weight (LMW) and high molecular weight (HMW) compounds were degraded using the developed systems. However, HMW compounds were more affected. The experimental results revealed that treatment at a high power level is not always a proper approach for a large reduction of PAH compounds. Whereas treatment at higher frequencies and lower power can be a suitable alternative to enhance the PAHs removal rate and the system energy efficiency and reduce losses. Therefore, a dual-mode ultrasound system with adjustable operating frequency and power is a promising approach for the treatment of industrial wastewater containing toxic PAH compounds.