Impacts of Nano-TiO₂ on System Performance and Bacterial Community and Their Removal During Biological Treatment of Wastewater

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• 作者：Guanglei Qiu ; Meng-Jun Au ; Yen-Peng Ting
• 关键词：Titanium dioxide nanoparticles (TiO2 NPs) ; Municipal wastewater treatment ; Sequencing batch reactor (SBR) ; Nitrification ; Extracellular polymeric substances ; Bacterial community dynamics
• 刊名：Water, Air, and Soil Pollution
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：227
• 期：10
• 全文大小：1,265 KB
• 刊物类别：Earth and Environmental Science
• 刊物主题：Environment
  Environment
  Atmospheric Protection, Air Quality Control and Air Pollution
  Waste Water Technology, Water Pollution Control, Water Management and Aquatic Pollution
  Terrestrial Pollution
  Hydrogeology
  
• 出版者：Springer Netherlands
• ISSN：1573-2932
• 卷排序：227

文摘

The effect of titanium dioxide nanoparticles (TiO₂ NPs) on biological wastewater treatment in a sequencing batch reactor was investigated. The overall removal of chemical oxygen demand (COD) and NH₄+-N were relatively unaffected; efficiencies remained at >95 % and around 99 %, respectively, after 30 days of continuous exposure to the NPs. However, TiO₂ NPs resulted in increased conversion of NO₂−-N to NO₃−-N and caused slight inhibition effect on denitrification, with the total nitrogen removal reduced from 95 to 90 %. Several shifts in the bacteria community composition were noted. However, the overall community structure and biodiversity remained relatively unchanged. The polysaccharide content in the extracellular polymeric substances (EPS) was generally unaffected, suggesting a low potential of substantial shock or damage that may result in cytoplasmic leakage. However, a decrease in protein content occurred and indicated the inhibitive effects of the NPs. TiO₂ NPs were removed in the system mainly via deposition into the sludge. The removal efficiency decreased from 90 to 70 % after 4 weeks, due to sorption saturation as well as the change in the EPS content of the activated sludge.