钢板电极处理亚甲基蓝模拟废水机理研究

Mechanism of Methylene Blue from Simulated Wastewater by Steel Plate Electrode

摘要: 采用钢板电极对亚甲基蓝(MB)模拟废水进行电化学处理，通过单因素条件试验，确定最佳工艺条件为：外加电压8 V，电解质(Na₂SO₄)浓度0.05 mol/L，极板间距1.5 cm，MB初始质量浓度300 mg/L，电解时间120 min。在此最佳条件下，MB去除率可达94.65%，TOC的去除率可达73.28%。通过GC-MS、IC分析，推测亚甲基蓝可能的降解途径：亚甲基蓝的C-N和C-S键被破坏，生成2-甲基-5,5-二苯基-4-甲硫基咪唑，随之氧化生成3-氨基-1,2-苯并异噻唑和酚类化合物，最终矿化为NO₃、CI−、SO₄^2-、CO₂、H₂O等小分子化合物。

Abstract: Electrochemical treatment of methylene blue (MB) simulated wastewater was carried out by steel plate electrode, and the single factor condition test was carried out. The optimum conditions were as follows: the applied voltage 8 V; the concentration of electrolyte 0.05 mol/L; the distance be-tween the plates 1.5 cm; the initial concentration of MB 300 mg/L; and electrolysis time 120 min. Under the optimum conditions, MB removal rate reached to 94.65% and the removal rate of TOC reached to 73.28%. The possible degradation pathways of methylene blue were analyzed by GC-MS and IC analysis. C-N and C-S bonds of methylene blue were destroyed to form 2-methyl-5,5-diphenyl-4-methylthioimidazole. And then oxidized to generate phenolic compounds and 3-amino-1,2-benzisothiazole, which was eventually transfered to NO₃, CI−, SO₄^2-, CO₂, H₂O and other small molecular compounds.