The presence of acetaminophen (APAP) in water and wastewater indicates its low susceptibility to conventional treatment. The application of new TiO2 nanocomposites containing pristine carbon nanotubes (MWCNT, 0.15-8.78 wt%) prepared by solgel method in acetaminophen removal from water was tested. The studied nanocomposites possessed a high surface area (348-421 m(2).g(-1)) with uniform framework-confined mesopores (primary mesopores) with an average pore width of about 3 nm. TiO2 was present as anatase with crystal size similar to 5-6 nm. The nanocomposites had an exposed more graphitized MWCNT surface with a lower content of C-O and O=C-O- surface groups. The addition of MWCNT reduced the band gap of TiO2 from 3.2 eV to 2.82 eV. Dark adsorption resulted in insignificant changes in APAP concentration. The greatest changes in APAP concentration during Vis irradiation over the tested nanocomposites were observed using CNT10 (Fig. 108). The highest efficiency was exhibited by the nanocomposite containing 1.72 wt% of MWCNT that enabled 81.6 +/- 0.6% removal of APAP from water. Generally, an increase of MWCNT concentration up to 1.72 wt% in the nanocomposites induced APAP removal. The nanocomposites possessing higher MWCNT addition were, however, not so efficient (63.2 +/- 2.4% and 62.2 +/- 4.2% removal). The enhanced photocatalytic activity of different nanocomposites is observed only in the narrow range. The obtained results confirmed that photogenerated holes and, to a lower extent, O-center dot(2)- and (OH)-O-center dot radicals played the key role in photocatalytic APAP removal over MWCNT-TiO2-SiO2. The studies using Vibrio fischeri have confirmed that photocatalytic oxidation is an effective method for reducing water toxicity.