Carbon-/Zeolite-Supported TiO2 for Sorption/Photocatalysis Applications in Water Treatment

The role of various carbon forms, i.e., activated carbon and carbon nanotubes/nanofibers as support for TiO2 in drinking water treatment, is discussed. Also, TiO2 supported onto zeolite that acts bifunctionally as a sorbent/photocatalyst for drinking water treatment is presented. The main contaminants of natural organic matter (NOM), arsenic species, and nitrogen compounds from drinking water sources by the type of groundwater and surface water can be removed/degraded by sorption/photocatalysis using TiO2 supported onto carbon and/or zeolite. TiO2 supported on powdered activated carbon (PAC-TiO2), granular activated carbon (GAC-TiO2), and zeolite (Z-TiO2), namely, supported TiO2, was synthesized through the sol-gel method, and TiO2 and multiwall carbon nanotubes/carbon nanofibers dispersed within epoxy matrix (CNT-TiO2-Epoxy, CNF-TiO2-Epoxy), namely, TiO2 composite, were obtained through the two-roll mill method. Kinetic study results through specific mathematic models allowed to elucidate some mechanistic aspects for sorption and photocatalysis for the application in drinking water. The intercalation of the carbon- and zeolite-supported TiO2 layers into a filtering system allows to develop a self-cleaning filtering system in drinking water.