Photocatalytic degradation of methylene blue dye and fungi Fusarium equiseti using titanium dioxide recovered from drinking water treatment sludge

Abstract

Massive amount of water treatment sludge is produced annually and majorly being treated via landfills which will eventually lead to the environmental problem. In this study, an attempt was made to evaluate the photocatalytic activity of titanium dioxide (TiO2) that was extracted from drinking water treatment plant sludge (DWTP) against methylene blue dye and fungi Fusarium equiseti. The TiO2 as white precipitate was formed at pH 6 using solvent extraction methods and further characterized using X-ray fluorescence (XRF), X-ray diffraction (XRD), and field emission scanning electron microscope (FESEM). Photocatalytic degradation of methylene blue solution by TiO2 was conducted in a closed home built-photocatalytic reactor. The effect of irradiation time, amount of loaded catalyst (TiO2) on the degradation of methylene blue and inhibition of F. equiseti were also investigated, respectively. The fungi F. equiseti was isolated and screened using polymerase chain reaction (PCR) with 100% identities. Results revealed that a maximum of 86% methylene blue degradation was achieved at 4-h reaction time with the 0.5 g/L of TiO2-loaded catalyst and 50% inhibition of the F. equiseti after 14 days. This work provides new insight into the TiO2 recovery from alternative resources and TiO2 as a high performance catalyst and facilitates its application in photocatalytic degradation of organic compounds.