粒子电极对苯酚废水的电催化降解

Electrochemical Oxidation of Phenol with Particle Electrodes

以溶胶-凝胶法制备了负载型复合金属氧化物Mn-Sn-Sb/γ-Al2O3粒子电极,用该粒子电极取代平板电极,对苯酚水溶液进行了电催化降解的研究,并考察了pH,电解质浓度,槽电压,进水ρ(苯酚),反应温度和气体流量等因素对苯酚去除率的影响.结果表明,当反应温度为25℃,pH为6.4,气体流量为0.5 L/min,槽电压为6.5 V,电解质浓度为0.025 mol/L时,电催化降解质量浓度为200 mg/L的苯酚水溶液150 min,苯酚去除率为94.0%,催化活性较高.提高进水ρ(苯酚),会使反应表现为自抑制作用;提高温度有利于苯酚电催化氧化的进行,但会增加石墨电极损耗和催化剂溶出量,因此在选择电催化氧化温度时要考虑设备的耐蚀性和电极的稳定性.

The electrochemical conversion of synthetic phenolic wastewater was studied in a batch electrochemical reactor. The plate electrodes were replaced by the particle-electrode of Mn-Sn-Sb complex metal oxides over γ-Al2O3 which was prepared by the sol-gel method. The effects of pH, electrolyte concentration, cell voltage, initial phenol concentration, reaction temperature and airflow on phenol conversion were elucidated. The results of the experiments indicated that the particle electrode had very high catalytic activity. The 94.0% phenol conversion could be obtained at the operating conditions as follows： temperature 25℃, initial pH 6.4, air flow 0.5 L/min, cell voltage 6.5 V, electrolyte concentration 0.025 mol/L and reaction time 150 min. Increased phenol concentration could decrease phenol destruction yield. And elevating the temperature would be in favor of the electrochemical oxidation, but increase in leached carbon anode and active ingredients of particle electrode was experienced in the runs due to the elevated the temperature. Therefore, corrosion resistance of equipment and electrode stability should be considered in selecting electrochemical temperature.