title: Impact of titanium dioxide nanoparticles on the bacterial communities of biological activated carbon filter intended for drinking water treatment.
abstract: Titanium dioxide nanoparticles (TiO2 NPs) are inevitably present in the aquatic environment owing to their increasing production and use. However, knowledge of the potential effects of TiO2 NPs on the treatment of drinking water is scarce. Herein, the effects of two types of anatase TiO2 NPs (TP1, 25 nm; TP2, 100 nm) on the bacterial community in a biological activated carbon (BAC) filter were investigated via quantitative polymerase chain reaction (Q-PCR) analysis, ATP quantification, and 454 pyrosequencing analysis. Both TP1 and TP2 significantly inhibited the bacterial ATP level (p < 0.01) and induced a decrease in the abundance of bacterial 16S rDNA gene copies at doses of 0.1 and 100 mg L(-1). Simultaneously, the diversity and evenness of the bacterial communities were considerably reduced. The relative abundances of bacteria annotated to OTUs from Nitrospira class and Betaproteobacteria class decreased upon TiO2 NP treatment, whereas those of Bacilli class and Gammaproteobacteria class increased. TiO2 NP size showed a greater effect on the bacterial composition than did the dose based on Bray-Curtis distances. These findings identified negative effects of TiO2 NPs on the bacterial community in the BAC filter. Given the fact that BAC filters are used widely in drinking water treatment plants, these results suggested a potential threat by TiO2 NP to drinking water treatment system.
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, China.
authors.forename: Liu
authors.initials: L
authors.lastname: Zhiyuan
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, China. 8566liliu@tongji.edu.cn.|College of Environmental Science and Engineering, Tongji University, Shanghai, 200092, China. 8566liliu@tongji.edu.cn.
authors.forename: Yu
authors.initials: Y
authors.lastname: Shuili
authors.affiliation: School of Civil, Environmental and Architectural Engineering, Korea University, Seoul, 136-714, South Korea.
authors.forename: Park
authors.initials: P
authors.lastname: Heedeung
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, China.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Qingbin
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, China.
authors.forename: Liu
authors.initials: L
authors.lastname: Guicai
authors.affiliation: State Key Laboratory of Pollution Control and Resources Reuse, Tongji University, Shanghai, 200092, China.
authors.forename: Li
authors.initials: L
authors.lastname: Qi
mesh_terms: D001419:Bacteria / Q000187:drug effects* / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification; D002606:Charcoal / Q000737:chemistry*; D060766:Drinking Water / Q000737:chemistry / Q000382:microbiology*; D053758:Nanoparticles / Q000633:toxicity*; D014025:Titanium / Q000633:toxicity*; D018508:Water Purification / Q000295:instrumentation* / Q000379:methods
chemical_list: D060766:Drinking Water; C009495:titanium dioxide; D002606:Charcoal; D014025:Titanium
keywords: 454 pyrosequencing; ATP quantification; Bacterial community; Drinking water treatment; Quantitative polymerase chain reaction; Titanium dioxide nanoparticle