研究了Fe²⁺活化过硫酸钠（SPS）在降解亚甲基蓝（MB）过程中溶液初始pH、Fe²⁺浓度、SPS浓度、Fe²⁺/SPS的最佳浓度比、MB的初始质量浓度对溶液中MB及COD降解效果的影响。结果表明，酸性环境MB的降解率要高于碱性环境，且溶液初始pH为3时MB的去除效果最佳。过高或过低的Fe²⁺浓度及SPS浓度对MB脱色效果都会产生一定的影响，且最佳投加比为C（Fe²⁺）∶C（S₂O₈^2-）=1∶2。当MB初始质量浓度为50 mg/L时，SPS与Fe²⁺的最佳投加浓度分别为0.4 mmol/L及0.2 mmol/L。Fe²⁺/SPS体系对于MB的脱色效果可达到80%~90%，对于氧化的中间产物的矿化度为20%~40%。当溶液初始温度<20℃时会使MB发生分子聚焦现象，随着溶液初始温度的升高，MB的脱色率随之升高，MB分子脱色的最佳反应温度为40℃。通过液相色谱质谱联用（LC-MS）分析可知，MB的氧化中间产物主要为二氨基苯酚、邻氨基苯酚、苯并噻唑、苯酚等苯的同系物。

In this study,Fe²⁺ activated sodium persulfate (SPS) is used in the degradation of methylene blue (MB).Influences of the initial solution pH,Fe²⁺ concentration,SPS concentration,Fe²⁺/SPS ratio and initial MB concentration on the degradation of MB and COD in the solution are studied.Results show that the degradation rate of MB in the acidic condition is higher than that in the alkaline condition.The removal efficiency of MB achieves the best at pH=3.Too high or too low concentrations of Fe²⁺ and/or SPS will have certain impact on the degradation of MB and the optimal dosing ratio is C(Fe²⁺):C(S₂O₃^2-)=1:2.The optimal dosing concentrations of SPS and Fe²⁺ are 0.4 mmol·L^-1 and 0.2 mmol·L^-1 respectively when the initial MB concentration is 50 mg·L^-1.MB decoloration by Fe²⁺/SPS system can reach 80%-90%.The intermediates in oxidation can get a salinity of 20% to 40% through Fe²⁺/SPS system.When the temperature of the solution is below 20℃,there appears molecular focus phenomenon in MB solution.With the increase of initial temperature in the solution,the de-coloring rate of MB will increase.The optimum reaction temperature for decoloration of MB molecules is 40℃.Analysis by means of liquid chromatography-mass spectrometry (LC-MS),the oxidative intermediates of MB mainly include diamino phenol,2-aminophenol,benzothiazole,phenol and other benzene homologues.

刘小佳(1992-),男,硕士研究生,研究方向为水处理,337118948@qq.com