Electrochemically assisted photocatalysis: Highly efficient treatment using thermal titanium oxides doped and non-doped electrodes for water disinfection

Abstract

Electrochemically assisted photocatalysis (by electronic drainage) is a highly promising method for disinfection of water. In this research, the efficiency of photolytic oxidation using UV-A radiation and electrochemically assisted photocatalysis (with electric potential of 1.5 V) was studied by using electrodes prepared by thermal treatment and doped with silver, for inactivation of Escherichia coli and Staphylococcus aureus. The Chick-Watson microorganism inactivation model was applied and the electrical energy consumption of the process was calculated. It was observed no significant inactivation of microorganisms when UV-A light or electric potential were applied separately. However, the electrochemically assisted photocatalytic process, with Ag-doped electrode completely inactivated the microbial population after 10 (E. coli) and 60 min (S. aureus). The best performing non-doped electrodes achieved 52.74% (E. coli) and 44.09% (S. aureus) inactivation rates after 60 min. Thus, electrochemically assisted photocatalytic activity was not only effective for the inactivation of microorganisms, but also notably low on electrical energy consumption during the treatment due to small current and low electric potential applied.

Disinfection of Wastewater by UV-Based Treatment for Reuse in a Circular Economy Perspective. Where Are We at?

“…Some works have reported more efficient degradation of bacteria by PEC compared to UV or PC [ 47 , 130 , 131 ] under similar experimental conditions. The lab-scale experiments of Nie et al [ 132 ] showed that For E. coli K-12 all bacterial cells were completely killed by the PEC process within 180 s, whereas only ca.…”

“…The traditional apparatus consists of continuous-wave mercury lamps in low pressure (monochromatic at 253.7 nm) or medium pressure (polychromatic in the UV and visible light ranges) formats [ 46 ]. UV lamps that emit radiation at 254 nm (UV-C) are the ones with the highest germicidal effect [ 47 ].…”

“…Photoelectrocatalysis (PEC) is an advanced oxidation process that involves the combination of conventional PC with the use of electricity [ 126 ]. The performance of the PC treatment can be adversely affected by the rapid recombination of the photogenerated electrons and holes (e − CB /h + VB ) [ 47 , 127 ] because each recombination leads to the loss of a hole that otherwise would have been a precursor of a disinfection reaction. Several studies suggested that, applying a constant current density or a constant bias anodic potential to the illuminated semiconductor prevents this recombination [ 14 , 15 ].…”

Oxidación electroquímica para la degradación de ciprofloxacíno asistida con radiación ultravioleta utilizando ánodos dimensionalmente estables

“…Uno de los procesos biológicos más populares son los procesos por lodos activos, mientras que, los procesos físicos comprenden a los de filtros empacados (arena, carbón activado); lamentablemente, la capacidad de remoción de los compuestos por estas metodologías es lograda solo parcialmente o, en ciertos casos el compuesto no sufre cambio alguno por lo que sólo es transportado de un medio a otro [1,3]. Entre los procesos químicos se ubican los AOPs, como procesos fotoquímicos, ya sean, ozonación, oxidación Fenton, tratamiento UV, electroquímica, entre otros [1,[4][5][6]. Estas tecnologías alternativas son eficientes en la degradación de compuestos orgánicos, debido a que muestran altos niveles de remoción y, sobre todo cuentan con una gran versatilidad en la desinfección de aguas por la generación de agentes con alto poder de oxidación.…”

“…4 , de las que se adicionaron 500 mL dentro del reactor. Una lámpara de mercurio Pen Ray de 254 nm (3300 −2 ) fue colocada de forma concéntrica dentro del reactor, manteniendo el sistema en agitación constante durante el proceso fotolítico.…”