摘要
The presence of TiO 2 nanoparticles (NPs) influences the efficiency of water and wastewater treatment because of the composite contaminants formed due to the interaction between TiO 2 NPs and Natural Organic Matter (NOM). In this study, the coagulation of TiO 2 NPs and NOM composite contaminants (TiO 2 NPs-NOM) was explored by comparing their fluorescence characteristics, flocs properties, and membrane fouling abilities in different aquatic media (i.e., humic acid synthetic water: WATER HA , surface water: WATER XQ ; and municipal wastewater: WATER MW ). Results showed that the TiO 2 NPs-NOM removal efficiency depended on the characteristics of NOM in various aquatic media. TiO 2 NPs improved the removal efficiency for fluorescent substances from WATER HA and WATER XQ when the solution pH was 5. However, this removal efficiency declined as the pH was increased to 9. In comparison, the removal efficiency for fluorescent substances from WATER MW increased as the TiO 2 NPs concentration was increased to 5 mg/L, and then decreased gradually as the TiO 2 concentration was increased to 20 mg/L. This is due to the competing adsorption and precipitation reactions between aromatic proteins and NPs. The different TiO 2 NPs-NOM in the tested water showed different flocs structures. The fractal dimensions of the flocs in WATER HA decreased with increasing TiO 2 NPs concentration until it exceeded 10 mg/L, while the fractal dimensions of WATER MW flocs increased with increasing TiO 2 NPs concentration. This was due to the formation of more loose flocs in the presence of aromatic proteins and soluble microbial byproducts . Total membrane resistance showed little change with increasing TiO 2 NPs concentration in the coagulation-ultrafiltration membrane process. The percentages of strongly attached external fouling resistance (Ref-s) and internal fouling resistance (R if ) increased with increasing TiO 2 NPs concentration.
危险品化学品经营许可证（带存储）