FePMo12催化电化学反应降解染料废水的研究

采用IR和XRD等方法对自制磷钼酸铁(FePMo12)杂多酸进行表征,表明杂多阴离子具有Keggin结构.将FePMo12负载于修饰后的4分子筛(4A)上制备FePMo12/APTES-4A催化剂填充于电化学反应器中,考察电化学氧化体系对酸性大红3R染料废水的脱色效果.结果表明,FePMo12/APTES-4A催化剂对酸性大红3R模拟废水具有良好的催化效果,当活性组分负载量为3%时,在pH为4,槽电压为22 V,曝气量为0.08 m3·h-1,极板间距为3.0 cm反应条件下,90 min后脱色率达到75.3%,COD和TOC去除率分别达到65.4%和46.0%.加入支持电解质Na2SO4和NaCl后,NaCl对电催化降解染料废水有促进作用,而Na2SO4的加入使得废水的脱色效率降低.采用可见-紫外光谱对反应过程中间产物进行分析,表明染料分子中的共轭体系已基本被破坏.

Enhanced Electro-Catalytic Oxidation of Dye Wastewater with FePMo12 Adopted Catalyst

Electrochemical oxidation degradation of azo dyes has become a widely used method in recent years. Iron phosphomolybdate (FePMo₁₂) was synthesized with molybdophosphoric acid and ferric salt. Morphology and microstructure of catalyst were characterized by IR spectrometry and X-ray diffraction. The heteropolyanion showed a Keggin structure. Electrochemical oxidation of acid red 3R was investigated in the presence of FePMo₁₂ supported on modified 4Å molecular sieve (4A) as packing materials in the reactor. The results showed that the optimal technological conditions for decolorization of acid red 3R simulated wastewater were as follows: active component load 3%, electrolytic voltage 22 V, initial pH 4, air-flow 0.08 m³·h^-1, electrode span 3.0 cm. Under the optimized conditions, the decolorization efficiency, COD and TOC removal efficiencies reached 75.3%, 65.4% and 46.0% after 90 min, respectively. With the addition of NaCl to the dyes solution during electrolysis, the decolorization efficiency increased, while the effect of Na₂SO₄ on the degradation was negative. The efficiency of degradation and mineralization of the acid red 3R were estimated based on the absorbance measurements by UV-vis. It shows that the conjugated structure of dye was destroyed primarily.