Sonochemical treatment of benzene/toluene contaminated wastewater

Abstract

AbstractStudies of the destruction of benzene and toluene in water were undertaken using ultrasonic irradiation in a parallel plate Near Field Acoustic Processor (NAP). This magnetostrictive system is capable of degrading both benzene and toluene in a continuous stirred tank reactor configuration. The reaction kinetics were characterized by first order rate constants for the disappearance of the parent compound; these ranged from 2.7 × 1−3 to 3.7 × 10−2 mm−1 over an applied power density range of 0.6 to 3.6 watt mL−1 and target concentration of approximately 25 to 900 µM. The rate constant is shown to be inversely proportional to the target compound concentration, indicating higher order reaction kinetics. The conversion efficiency for the system was characterized through the “G” efficiency commonly used in radiation chemistry. The G efficiency ranged between 4 × 10−5 to 2.2 × 10−4 molecules destroyed per 100 eV of electrical energy drawn from the wall outlet. These values are comparable to those of other advanced oxidation processes. Suggestions are made regarding methods to improve this technology.