Clays for heterogeneous photocatalytic decolorization of wastewaters contaminated with synthetic dyes: a review

Photocatalysis is one of the most environment-friendly and technologically viable advanced oxidation processes. Compared to conventional thermal, biological, and physicochemical treatments, photocatalytic processes have more moderate reaction conditions and higher efficiency. They are a promising technology for the treatment of dye wastewaters, particularly those that have toxic and high organic content. Matrix-based photocatalysts have been extensively studied to enhance their efficiency. This paper is a review of recently published literature on matrix-based clay photocatalysts – e.g., bentonite, attapulgite, hydrotalcite, etc. – decolorizing dye wastewaters.