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为了实用的目的,在实验室进行了静态法与流动法研究TNT水溶液光氧化动力学实验。 实验结果表明: (1)TNT水溶液在UV—H_2O_2作用下遵循lnc╱c_0=-kt(1)的动力学方程式,式中c_0为TNT水溶液原始浓度,c为t时浓度,t为光氧化时间,k为光氧化速率常数。用(1)式可估计TNT水溶液光氧化达排放标准所需时间。 (2)光氧化速率常数k,在相同条件(UV光强,光照面积,液层厚度和H_2O_2浓度),与TNT水溶液初浓度有关,遵循lnk=-mc_0+B(2)关系,式中kc_0与(1)式同,m和B为经验常数。用(2)式可估算将TNT水溶液稀释以节约电能的程度。 (3)光氧化速率常数k与温度无关。 (4)速率常数k与H_2O_2初浓度有关,存在一最佳H_2O_2初浓度,而且此最佳值随TNT水溶液原始浓度增加而增大。 由液相、薄层色谱分析知此光氧化过程是一复杂反应,其机理正在进一步研究中,上述宏观动力学规律是否适用于工业废水也待确定。
For practical purposes, static and flow methods were used in the laboratory to study the photooxidation kinetics of aqueous TNT solution. The experimental results show that: (1) TNT aqueous solution follows the kinetic equation lnc ╱ c_0 = -kt (1) under the action of UV-H_2O_2, where c_0 is the initial concentration of TNT aqueous solution, c is the concentration at t, t is the photooxidation time , k is the photooxidation rate constant. (1) can be estimated TNT aqueous solution of light oxidation up to the emission standard time. (2) The photooxidation rate constant k is related to the initial concentration of TNT aqueous solution under the same conditions (UV light intensity, light area, liquid layer thickness and H 2 O 2 concentration), and follows the relation of lnk = -mc_0 + B (2) Like (1), m and B are empirical constants. Equation (2) can be used to estimate the degree of dilution of the aqueous TNT to save electrical energy. (3) Photooxidation rate constant k is independent of temperature. (4) The rate constant k is related to the initial concentration of H 2 O 2, and an optimum initial concentration of H 2 O 2 exists, and the optimum value increases with the initial concentration of TNT aqueous solution. From the liquid and thin layer chromatographic analysis, the photooxidation process is a complex reaction. The mechanism is under further study. Whether the macroscopic kinetic law is suitable for industrial wastewater is yet to be determined.