Emerging nanomaterials are of great concern to aquatic environment. The inhibitory effects of silver nanoparticles (Ag-NP) and titanium oxide nanoparticles (TiO 2 -NP) on the growth of aquatic plant duckweed were evaluated. Lemna paucicostata was used as a test organism, and the test method was followed by the OECD test guideline 221. Ag-NP (50 nm) and TiO 2 -NP (2-3 nm) inhibited the growth of Lemna in different manner and the EC50s were calculated as 13.8 and 538.5 ppm, respectively. The LOECs of Ag-NP and TiO 2 -NP were calculated to be 1 and 125 ppm, respectively. The results showed that Ag-NP could cause growth inhibition of Lemna in low concentration range (›1 ppm), but TiO 2 -NP appeared toxic effect to the growth of Lemna in the concentration range of ›250 ppm, which was over two orders higher than the previously reported concentration of TiO 2 -NP determined in the aquatic environment.

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Visible light-induced degradation of gas-phase acetaldehyde (CH 3 CHO) is investigated using O-deficient reduced TiO 2Àx -loaded carbon paper. The carbon paper is synthesized by the pyrolysis of a filter paper, and the reduced TiO 2Àx is prepared by the magnesiothermic reduction of commercial anatase TiO 2 . The surface areas of the non-carbonized filter paper and carbon papers obtained by carbonization at 400, 600, 800, and 1000 C are 4. (l > 420 nm), attributed to the efficient adsorption of gas-phase CH 3 CHO by the carbon paper and the rapid and complete degradation of CH 3 CHO to CO 2 by the active reduced TiO 2Àx . This strongly suggests that the reduced TiO 2Àx -loaded carbon paper is an efficient composite photocatalyst for the visible light-induced photocatalytic degradation of gas-phase CH 3 CHO.

Poly (ethylene terephthalate)(PET)/Al2O3nanocomposites via in situ polymerization were studied. The nanoparticle loading was varied from 0.3 to 1 wt.%. From the DSC results, no significant differences were recorded for melting temperatures. However, simple added PET/Al2O3nanocomposites slightly changed to the lower melting temperature. Morphology of the nanocomposites has been examined by SEM. From the SEM results revealed that dispersed Al2O3nanoparticles in the EG (ethylene glycol) during the polymerization can be well dispersed in PET matrix.