光催化降解水介质中的人工甜味剂安赛蜜

Photocatalytic Degradation of the Artificial Sweetener Acesulfame in Aqueous Media

研究了紫外(UV)体系对水介质中人工甜味剂安赛蜜降解的影响因素和动力学模型。结果表明,在相同的pH值下,光降解反应速率常数随安赛蜜初始浓度升高而减小;不同安赛蜜初始浓度下,光降解反应速率常数受到pH值的影响也不同。当安赛蜜初始平均浓度为13 mg/L时,在pH值为7时的光降解速率最快,且在反应时间6 h内符合一级反应动力学模型,光降解速率常数为0.819 0 h^(-1)。安赛蜜初始平均浓度为108 mg/L时,在p H=9时光降解反应速率常数最大为0.223 4 h^(-1)。安赛蜜初始平均浓度为54 mg/L时,在pH为7和9且反应时间6 h内符合一级反应动力学模型,光降解速率常数分别为0.350 38和0.361 93 h^(-1)。

The influencing factors of acesulfame degradation and kinetic model by ultraviolet（UV） photocatalysis were investigated. The results showed that the photodegradation rate constant decreased with the increased initial concentration of acesulfame under the same pH value. At different initial acesulfame concentrations,the photodegradation rate constants were different on the effects of pH value. When the initial concentration of acesulfame was 13 mg/L,the photodegradation rate was the highest at pH value of 7, and the degradation conformed with the first order reaction in 6 hours with photodegradation rate constant of 0.819 0 h-1. However,when the initial concentration of acesulfame was 108 mg/L,the photodegradation rate constant（0.223 4 h-1） was the highest at pH value of 9. When the initial concentration of acesulfame was 54 mg/L and pH value was 7 and 9,the degradation of acesulfame conformed with the first order reaction in 6 hours,and the photodegradation rate constant was respectively 0.35038 and 0.361 93 h-1.