García-Espinoza Josué Daniel, Robles Irma, Durán-Moreno Alfonso, Godínez Luis A
Centro de Investigación y Desarrollo Tecnológico en Electroquímica, Parque Tecnológico Querétaro Sanfandila, 76703, Pedro Escobedo, Querétaro, Mexico.
Facultad de Química, Universidad Nacional Autónoma de México, CDMX, Mexico.
Chemosphere. 2021 Jul;274:129957. doi: 10.1016/j.chemosphere.2021.129957. Epub 2021 Feb 12.
Disinfection is usually the final step in water treatment and its effectiveness is of paramount importance in ensuring public health. Chlorination, ultraviolet (UV) irradiation and ozone (O) are currently the most common methods for water disinfection; however, the generation of toxic by-products and the non-remnant effect of UV and O still constitute major drawbacks. Photo-assisted electrochemical advanced oxidation processes (EAOPs) on the other hand, appear as a potentially effective option for water disinfection. In these processes, the synergism between electrochemically produced active species and photo-generated radicals, improve their performance when compared with the corresponding separate processes and with other physical or chemical approaches. In photo-assisted EAOPs the inactivation of pathogens takes place by means of mechanisms that occur at different distances from the anode, that is: (i) directly at the electrode's surface (direct oxidation), (ii) at the anode's vicinity by means of electrochemically generated hydroxyl radical species (quasi-direct), (iii) or at the bulk solution (away from the electrode surface) by photo-electrogenerated active species (indirect oxidation). This review addresses state of the art reports concerning the inactivation of pathogens in water by means of photo-assisted EAOPs such as photo-electrocatalytic process, photo-assisted electrochemical oxidation, photo-electrocoagulation and cathodic processes. By focusing on the oxidation mechanism, it was found that while quasi-direct oxidation is the preponderant inactivation mechanism, the photo-electrocatalytic process using semiconductor materials is the most studied method as revealed by numerous reports in the literature. Advantages, disadvantages, trends and perspectives for water disinfection in photo-assisted EAOPs are also analyzed in this work.
消毒通常是水处理的最后一步，其有效性对于确保公众健康至关重要。氯化、紫外线（UV）照射和臭氧（O₃）是目前最常用的水消毒方法；然而，有毒副产物的产生以及紫外线和臭氧的非残留效应仍然是主要缺点。另一方面，光辅助电化学高级氧化工艺（EAOPs）似乎是一种潜在有效的水消毒选择。在这些工艺中，与相应的单独工艺以及其他物理或化学方法相比，电化学产生的活性物种与光生自由基之间的协同作用提高了它们的性能。在光辅助EAOPs中，病原体的灭活通过在距阳极不同距离处发生的机制进行，即：（i）直接在电极表面（直接氧化），（ii）通过电化学产生的羟基自由基物种在阳极附近（准直接），（iii）或通过光生电活性物种在本体溶液中（远离电极表面）（间接氧化）。本综述阐述了有关通过光辅助EAOPs（如光电催化过程、光辅助电化学氧化、光电凝聚和阴极过程）使水中病原体失活的最新报告。通过关注氧化机制发现，虽然准直接氧化是主要的灭活机制，但如文献中众多报告所揭示的，使用半导体材料的光电催化过程是研究最多的方法。本文还分析了光辅助EAOPs在水消毒方面的优点、缺点、趋势和前景。
