To reduce or eliminate the inhibition effect of natural organic matters (NOMs) in water on TiO2 photocatalysis for removal of emerging contaminants, four activated carbon/titanium dioxide (AC/TiO2) composites with different pore structure were prepared by hydrothermal method. The results showed that anatase TiO2 particles were uniformly distributed in the pores or onto the surface of activated carbons. The total removal rate of 6 mg L-1 17α-ethinylestradiol (EE2) on the four AC/TiO2 composites reached above 90%, 30% higher than that of EE2 on TiO2. The degradation rate constants of EE2 on four kinds of AC/TiO2 were much higher than that on TiO2. Further study indicated that the adsorption removal ratio of EE2 on the composites was slightly reduced mainly because competitive adsorption between hydrophilic NOMs (HA and FA) and EE2 molecules when HA and FA coexisted with EE2 in water. But importantly, the obvious inhibitory effect of FA for TiO2 photocatalysis was eliminated on four composites because the introduction of AC with excellent adsorption capacity can preferentially transfer hydrophobic EE2 molecules onto adsorption sites of TiO2/AC composites.
Keywords: Activated carbon; Adsorption/photocatalysis; Dissolved organic matter; Inhibitory effect; Titanium dioxide.
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