超声波-光催化联合降解苯酚废水研究

Combinative degradation of phenol aqueous solution with sonolysis and photocatalysis

超声降解和光催化降解均为自由基历程的高级氧化技术,同时,超声空化能够改善传质效果,因此,二者耦合能否产生协同效果是值得研究的。本文考察了苯酚溶液的超声降解、光降解、光催化降解、超声-光催化降解以及温度对光降解和光催化降解的影响。结果表明,40kHz,0.4w/cm2的超声波对苯酚没有明显的降解作用,而对光催化降解只有轻微的促进作用。光降解和光催化降解的过程曲线显著不同,但温度对二者均有显著的促进作用。

Sonolysis and photocatalysis are both advanced oxidation technologies following free radical mechanism, and ultrasonic cavitation can improve the mass transfer between photocatalyst and liquid, therefore, investigation on the possible cooperative effect is of significance. In this paper, sonolysis, photolysis, photocatalysis with titanium dioxide, ultrasound induced photocatalysis of phenol solution, and the temperature effect on both photolysis and photocatalysis were studied. It was proved that the ultrasound at 40 kHz and 0. 4 W/cm2 have no obvious effect on phenol degradation, and its promotion on photocatalysis is also marginal. The difference between photolysis and photocatalysis curves is of prominence which implies that photocatalyst can notably decrease the concentration of intermediate produced in the degradation process. Meanwhile, temperature has a remarkable promotion on both degrading processes.