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12:47
Tangential Flow Ultrafiltration: A “Green” Method for the Size Selection and Concentration of Colloidal Silver Nanoparticles
Published on: October 4, 2012
Removal of silver nanoparticles by coagulation processes.
1Key Laboratory of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
Journal of Hazardous Materials
|August 27, 2013
Summary
Conventional water treatment processes effectively remove silver nanoparticles (AgNPs) from drinking water. Coagulation and sedimentation can minimize human exposure to AgNPs, even with varying water conditions.
Area of Science:
- Environmental Science
- Nanotechnology
- Water Treatment
Background:
- Commercial applications of silver nanoparticles (AgNPs) raise concerns about human exposure through potable water.
- Conventional drinking water treatment, including coagulation and sedimentation, may act as a barrier against AgNP exposure.
Purpose of the Study:
- To investigate the removal efficiency of AgNP suspensions using four common coagulants.
- To determine the influence of water parameters on AgNP removal during coagulation.
Main Methods:
- Tested AgNP removal using aluminum sulfate, ferric chloride, poly aluminum chloride, and polyferric sulfate.
- Analyzed the impact of pH, natural organic matter (NOM), Ca(2+), and suspended solids on removal efficiency.
- Utilized transmission electron microscopy (TEM) and X-ray diffraction (XRD) to characterize AgNP adsorption onto flocs.
Main Results:
- AgNP removal varied among coagulants; poly aluminum chloride and polyferric sulfate showed optimal removal at pH 7.5.
- Increased NOM, Ca(2+), and suspended solids generally reduced AgNP removal efficiency.
- TEM and XRD confirmed AgNPs were adsorbed onto the formed flocs.
Conclusions:
- Coagulation/sedimentation is a viable method for removing AgNPs from source water.
- Optimized coagulation conditions can effectively minimize AgNP presence and reduce silver ion concentrations in treated water.
- Traditional water treatment processes offer a protective measure against AgNP contamination in drinking water.
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