负载过渡金属颗粒电极催化降解焦化废水尾水

制备以活性炭为载体，负载Ni、Fe、Co单元素和Ni-Fe、Co-Fe双元素的5种颗粒电极，用以降解模拟焦化废水尾水.结果显示，负载双元素的颗粒电极对模拟废水的处理效果要好于单元素，其中Ni-Fe/PAC降解性能最好，COD与TOC降解率可达70.1%和40.1%.Ni-Fe/PAC也具有最高的析氧电位和最低的Tafel斜率，分别为2.25V和86mV/dec；所负载的晶体结构为单质Ni和Fe，含有少量的铁氧化物.颗粒电极的添加，会导致出水呈碱性，Co的掺入导致碱性增大，而Fe的掺入有利于降低出水pH值.模拟废水中3类有机物在Ni-Fe/PAC上降解效果呈现为多环芳烃<杂环化合物<苯系物.Ni-Fe/PAC能催化·OH和新生态氢的产生，有机物的降解以间接氧化为主.

Catalytic degradation of coking tail wastewater by particle electrodes loaded with transition metals

Large quantities of refractory organic matters still leave in the coking wastewater after biological treatment, making wastewater not meet the requirements of discharge or recycling. In the present study, activated carbon was applied as carrier. Five kinds of particle electrodes that were loaded with single elements of Ni, Fe and Co and binary elements of Ni-Fe and Co-Fe, were prepared and used to degrade the simulated coking tail-wastewater. The results showed that the particle electrodes loaded with binary elements achieved better treatment effects than those loaded with single elements. Ni-Fe/PAC possessed the best degradation performance among the electrodes, with COD and TOC removal efficiency of 70.1% and 40.1%, respectively. Ni-Fe/PAC also possessed the highest oxygen evolution potential and the lowest Tafel slope, namely 2.25V and 86mV/dec, respectively. The crystal structure was consisted by metallic Ni and Fe and small amount of iron oxide. The addition of particle electrodes resulted in the effluent to be alkaline. The loading Co increased the alkalinity, while the Fe was beneficial to reduce the pH value of effluent. The degradation effects of the three category organics in simulated wastewater were in the order of polycyclic aromatic hydrocarbon < heterocyclic compound < benzene series during Ni-Fe/PAC processes. Ni-Fe/PAC can catalyze the generation of ·OH and new atomic hydrogen. The degradation of organic matters was mainly fulfilled through indirect oxidation.