Mg-Al CLDHs/H_2O_2体系降解结晶紫染料废水的研究

Degradation of Crystal Violet Dye Wastewater under Mg-Al CLDHs/H_2O_2 System

以Mg-AlCLDHs(Calcined Mg-Al layered double hydroxide)和H2O2组成的类芬顿体系催化降解结晶紫(Crystal violet,CV)染料废水。考察了p H值、催化剂用量、氧化剂用量、染料起始浓度、反应温度、反应时间等因素的影响,并对Mg-Al CLDHs催化剂的再生能力进行了测试。结果表明:对浓度为40 mg/L的结晶紫溶液,当Mg-Al CLDHs用量为0.005 g,H2O2用量为1 m L,p H为7.0,降解温度为35℃,反应时间为15 min,结晶紫脱色率98%以上,催化剂再生性良好。动力学研究表明该反应符合一级动力学模型,35℃时速率常数为0.28 min-1,表观活化能为46.03 k J·mol-1。

Mg-Al CLDHs was used as heterogeneous catalysts with H202 as oxidant in the CV degradation reaction. The effects of initial pH, amounts of consumed catalyst and H2O2, initial concentration of dyes, reaction temperature and time duration were researched. And the recyelability of Mg-Al CLDHs was also estimated. Results showed that 98 % decolorization rate of CV can be obtained by adding 0. 005 g catalyst of Mg-Al CLDHs and 1mL oxidant of H202 to a 40 mg/L dye wastewater with pH value of 7 at the temperature of 35 ℃ for l5 min. Mg-Al CLDHs also has a relatively well recyelability. Kinetic study indicates that the degradation processes of CV by Fenton-like system of Mg-Al CLDHs/H202 are coincidence to the first-order kinetic equation. The reaction constant and activity energy are 0. 28 min ^-1 and 46.03 kJ· mol^-1 at 35 ℃, respectively.