Retention of titanium dioxide nanoparticles in bio

Authors: Zhiyuan Liu Shuili Yu Heedeung Park Guicai Liu Qingbin Yuan

Publish Date: 2016/03/01

Volume: 27, Issue: 2-3, Pages: 95-106

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Abstract

Given the increasing discoveries related to the ecotoxicity of titanium dioxide TiO2 nanoparticles NPs in different ecosystems and with respect to public health it is important to understand their potential effects in drinking water treatment DWT The effects of TiO2 NPs on ammonia reduction ammoniaoxidizing archaea AOA and ammoniaoxidizing bacteria AOB in biological activated carbon BAC filters for drinking water were investigated in static and dynamic states In the static state both the nitrification potential and AOB were significantly inhibited by 100 μg L−1 TiO2 NPs after 12 h p  005 and the threshold decreased to 10 μg L−1 with prolonged exposure 36 h p  005 However AOA were not considerably affected in any of the tested conditions p  005 In the dynamic state different amounts of TiO2 NP pulses were injected into three pilotscale BAC filters The decay of TiO2 NPs in the BAC filters was very slow Both titanium quantification and scanning electron microscope analysis confirmed the retention of TiO2 NPs in the BAC filters after 134 days of operation Furthermore the TiO2 NP pulses considerably reduced the performance of ammonia reduction This study identified the retention of TiO2 NPs in BAC filters and the negative effect on the ammonia reduction suggesting a potential threat to DWT by TiO2 NPsThis work was supported by “The National Major Project of Science Technology Ministry of China No 2012ZX07403001” which is devoted to securing the drinking water safety of the Tai Lake area We are also grateful to the workers of the Wujiang Huayan Waterworks for their help in preparing the infrastructure for the pilotscale test

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