A critical review over the electrochemical disinfection of bacteria in synthetic and real wastewaters using a boron-doped diamond anode

Abstract

Inadequate access to clean water and sanitation are the most relevant problems afflicting developing and industrialized nations. Global water scarcity is expected to grow worse in the coming decades and this has motivated the scientific community to identify new, safe, and robust water disinfection technologies at lower cost and with less energy, diminishing the use of chemicals and impact on the environment. Usually, conventional methods of water treatment can solve this problem satisfactorily, such as chlorination, but, sometimes, they can be chemically, energetically, and operationally intensive. Therefore, the science and technology has encouraged the development of other alternative disinfection technologies. In this frame, electrochemical disinfection or electrodisinfection is currently experiencing a renaissance due to the tremendous contributions of novel electrocatalytic materials as well as the use of electric current as an inexpensive and suitable reagent to drive the inactivation of waterborne pathogens, avoiding conventional chemical oxidizers or reducing agents. Electrodisinfection has a significant technical impact, because it can be easily scaled up or design small–portable devices, benefiting from advantages such as versatility, environmental compatibility, automation, inherent safety, and potential cost effectiveness among others. Diamond films emerge as a novel and sustainable solution to electrogenerate powerful oxidants for effectively controlling waterborne pathogens in drinking water. The overarching goal of this critical review is to evidence the importance of diamond electrochemical methods as alternative for the eradication of waterborne infectious agents from public and drinking waters. The mechanisms of bacteria inactivation, and the fundamentals and applications of electrochemical oxidation with diamond to disinfect synthetic and real waters and wastewaters are exhaustively discussed. The use of hybrid and sequential processes involving electrochemical oxidation with other techniques, as well as endodontic and food control applications, are also analyzed. A section remarking the future challenges of electrodisinfection with diamond is finally presented.