研究三氯甲烷在单独超声(US)、单独零价铁(Fe^0)及超声波/零价铁协同体系(US/Fe^0)中的降解发现,拟一级动力学能很好地拟合降解过程,协同体系中三氯甲烷一级降解速率常数(KUS/Fe0)为0.0103min^-1,约为同等条件下零价铁体系所得KFe^0的3倍,且大于KFe^0与KUS之和,说明二者之间存在协同效应.考察零价铁投加量〔ρ(Fe^0)〕,初始pH,初始三氯甲烷浓度(c0),超声功率,溶液离子强度等控制参数对三氯甲烷降解速率(KUS/Fe^0)的影响,结果表明,其拟一级速率常数分别在ρ(Fe^0)为6g/L,初始pH为6.0,c0为5mmol/L以及0.5mol/LNa2SO4当量离子强度下达最大值,并且随着超声功率的增大而增大.
Trichloromethane degradation in the synergistic system of ultrasound and elemental iron was investigated. The results indicated that the degradation process of trichloromethane can be perfectly fitted by the pseudo-first-order kinetics. The first-order rate constant of degradation ( KUS/Fe^0 ) of trichloromethane in this synergistic system was 0. 010 3 min^-1 , which was almost threefold as large as Fe^0 , and was higher than the sum of Kus and Fe^0 . This suggested that synergistic effects existed between ultrasound and Fe^0 . This study also investigated the effects of ρ(Fe^0), initial pH, initial trichloromethane concentration (c0), ultrasonic power and ionic strength on the degradation rate of trichloromethane. The results showed that the pseudo-first-order rate constant reached the highest at the conditions of/9 (Fe^0) = 6 g/L, initial pH = 6.0, co = 5 mmol/L, and c (Na2 SO4 ) = 0.5 mol/L, and the pseudo-first-order rate constant increased with increasing ultrasonic power.