Effects of suspended titanium dioxide (TiO2) nanoparticles on cake layer formation in submerged anaerobic membrane bioreactor (AnMBR) for landfill leachate treatment (LFL).

In recent years, TiO 2 NPs have attracted great attention among the semiconductors because of stability, commercial availability, and ease of preparation. For this reason, NPs are widely used in wastewater treatment and membrane bioreactor (MBRs) In this study, the effect of titanium dioxide (TiO2) nanoparticle material was investigated on both the landfill leachate (LFL) treatment and membrane fouling performance. The system performance was evaluated for under varying TiO 2 concentrations (50–300 mg/L TiO 2), constant HRT (24 h), and constant backwashing (5 min)-relaxing (0.5 min) in AnMBR. The optimum conditions were determined as 300 mg/L TiO 2 and the corresponding to COD, Color, TOC and TN removal efficiencies were observed as 55 %, 23 %, 22 %, 30 %, respectively. The best membrane performance was observed at 300 mg/L TiO 2 corresponding to membrane fouling rate as 0.01 mbar/min. TiO 2 addition significantly mitigated membrane fouling (75 % decrease) for AnMBR. Bacteroidetes, Firmicutes and Proteobacteria have been observed to be the dominant species in LFL and MBRs. The bacterial species responsible for membrane fouling were determined as Alphaproteobacteria, Sphingobacteria and Flavobacteria. The addition of TiO 2 was determined membrane fouling decreased in AnMBR. As a result of TiO 2 NPs were observed to thin the cake layer and postpone membrane fouling and filtration. [Display omitted] • The best membrane performances were observed at 300 mg TiO 2 /L. • Membrane fouling rate was determined as 0.01 mbar/min. • TiO 2 addition significantly mitigated membrane fouling (75 % decrease). • TiO 2 prevents cake layer formation and/or pore clogging and postpone. • Bacteroidetes, Firmicutes and Proteobacteria have been observed as dominant species. [ABSTRACT FROM AUTHOR]