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Sorption of Phenanthrene on Nano-TiO2 Coated with Humic Acid |
Received:March 18, 2014 |
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KeyWord:humic acid;titanium dioxide;sorption;phenanthrene |
Author Name | Affiliation | E-mail | LI Yan-jie | College of Environment and Energy, South China University of Technology, Guangzhou 510006, China | | MA Tian-xing | College of Environment and Energy, South China University of Technology, Guangzhou 510006, China | | GUO Xue-tao | College of Environment and Energy, South China University of Technology, Guangzhou 510006, China | | YANG Chen | College of Environment and Energy, South China University of Technology, Guangzhou 510006, China Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control, South China University of Technology, Guangzhou 510006, China | cyanggz@scut.edu.cn | DANG Zhi | College of Environment and Energy, South China University of Technology, Guangzhou 510006, China Key Laboratory of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangdong, Guangzhou 510006, China | |
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Abstract: |
Nano-TiO2 has strong adsorption of pollutants. Humic acid(HA) is a natural organic substance and also influences the environmental fates of pollutants. A bath adsorption experiment was conducted to study the sorption of phenanthrene on nano-TiO2 as influenced by initial concentrations of phenanthrene, pH values and ionic strength under the presence of peat HA and sediment HA. The sorption kinetics of phenanthrene was also investigated. The Kd value of nano-TiO2 was 6.71 L·kg-1, while that of nano-TiO2 coated with peat and sediment HA was 715 L·kg-1 and 348 L·kg-1, respectively, indicating that HA coating enhanced the sorption of phenanthrene on nano-TiO2. The increment of sorption by aromatic-rich HA was significantly greater than that by aliphatic-rich HA. The equilibrium time decreased to 48 h from 168 h under the presence of HA, implying a quicker equilibrium of phenanthrene sorption on nano-TiO2 coated with HA.The kinetics of phenanthrene sorption followed the pseudo second-order rate equation. Both pH and ionic strength had greater influence on phenanthrene sorption by nano-TiO2 coated with aromatic-rich HA than with aliphatic-rich HA. Therefore, the influence of humic acid and environmental factors should not be ignored when evaluating the environmental impacts of nano-TiO2. |
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