超声波降解全氟辛烷磺酸和全氟辛酸的动力学

引 言全氟辛烷磺酸基化合物和全氟辛酸化合物是一类重要的全氟化表面活性剂,也是其他许多全氟化合物的重要前体.自20世纪60年代电化学氟化反应方法应用于全氟辛烷磺酸(PFOS)和全氟辛酸(PFOA)等全氟化合物的生产以来,已有上百种含有磺酰基的全氟有机化合物系列产品被开发生产并获得大量应用[1-2],美国3M公司曾是世界上最大的PFOS和PFOA生产厂家.

Kinetics of perfluorooctane sulfonate and perfluorooctanoate degradation by ultrasound irradiation

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.