photodegradation of gaseous acetaldehyde and methylene blue in aqueous solution with titanium dioxide-loaded activated carbon fiber polymer materials and aquatic plant ecotoxicity tests

摘要

TiO_2-supported activated carbon felts (TiO_2-ACFTs) were prepared by dip coating of felts composed of activated carbon fibers (ACFs) with either polyester fibers (PS-A20) and/or a polyethylene pulp (PE-W15) in a TiO_2 aqueous suspension followed by calcination at 250 °C for 1 h. The as-prepared TiO_2-ACFTs with 29-35 wt.% TiO_2 were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and N_2 adsorption. The TiO_2-ACFT(PS-A20) samples with 0 and 29 wt.% TiO_2 were microporous with specific surface areas (S_(BET)) of 996 and 738 m~2/g, respectively, whereas the TiO_2-ACFT(PE-W15) samples with 0 and 35 wt.% TiO_2 were mesoporous with S_(BET) OF 826 and 586 m~2/g, respectively. Adsorption and photocatalytic activity of the as-prepared samples were eval-uated by measuring adsorption in the dark and photodegradation of gaseous acetaldehyde (AcH) and methylene blue (MB) in aqueous solution under UV light. The TiO_2 loading caused a considerable decrease in the S_(BET) and MB adsorption capacity along with an increase in MB photodegradation and AcH mineralization. Lemna minor was chosen as a representative aquatic plant for ecotoxicity tests measuring detoxification of water obtained from the MB photodegradation reaction with the TiO_2-ACFT samples under UV light.