Abstract:

The feasibility of perfluorooctane sulfonate (PFOS)and perfluorooctanoate (PFOA)degradation by ultrasound irradiation was studied, and the effects of ultrasonic frequency, initial PFOS and PFOA concentration, initial pH, sorts of saturated gas, various organic and inorganic compounds coexisting with PFOS and PFOA, on the sonochemical decomposition rates were evaluated.The experimental results showed that PFOS and PFOA degradation followed the pseudo-first order kinetics in range of initial concentration 10—3650 μg·L^-1.Complete sonolysis could be reached over a range of frequencies from 200 to 610 kHz and at 100 μg·L^-1 of initial concentration.However, the degradation rate constants has an apparent maximum at 358 kHz, and at this frequency, the influences of initial concentration, initial pH and sorts of saturated gas on PFOS and PFOA degradation are great.Volatile aliphatic and aromatic organic components have effect on the degradation, while inorganic compound NaClO₄ could accelerate the degradation rates.