Adsorption/Desorption of Pollutants to Nanoparticles Mason Tomson, V. L. Colvin Xuekun Cheng, Y. Gao, R. Wahi, A. T. Kan Center for Biological and Environmental Nanotechnology Civil and Environmental Engineering and Chemistry Departments Rice University September 15, 2003
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Adsorption/Desorption of Pollutants to Nanoparticles
Mason Tomson, V. L. ColvinXuekun Cheng, Y. Gao, R. Wahi, A. T. Kan
Center for Biological and Environmental NanotechnologyCivil and Environmental Engineering and Chemistry
DepartmentsRice University
September 15, 2003
Adsorption/Desorption Hysteresis
Reaction Uptake
BiodegradationVolatilization
DesorptionToxicity
Black Carbon
Sorption/Desorption HysteresisdespK
adspK>
0.00.51.01.52.02.5
Solid
Pha
seC
onc
(µg/
g)
0.0 0.2 0.5 0.8 1.0
Solution Phase Conc (µg/ml)
Naphthalene/LulaDesorption
Adsorption
Rev. Irr.
max
max
Water
~0.01
102030
0.02 (µg/
ml)
(µg/
g)
"Unweathered,non-remediated, or freshly
contaminated"
"Weathered,remediated, or aged"
Sediment
Rev. Irr.1 02 0
4 05 06 0
3 0
max
max
Rev.
~
Water
0.01
102030
0.02
Irr.
1020
405060
30
Irr.Rev.
Sediment
(µg/
ml)
(µg/
g)
Adsorption/Desorption Hysteresis
0.1
10
103
105
10-7 10-5 0.1 10 1000Solution Phase Conc (mg/L)
102
105
104
103
106
K OC=10
7 Boston Harbor:1. Phenanthrene2. Pyrene3. Cl 5-PCB4. Cl 6-PCB
Lake Charles, LA :5. Cl 2-Benzene6. Cl 3-Benzene7. Cl 4-Benzene8. Cl 6-Benzene9. Cl 6-Butadiene
States of aggregation of nanoparticles may change in various aqueous environmentAdsorption of contaminants to the surfaces of nanoparticles is very strongAdsorption/desorption of organic compounds to nanoparticles might be hystereticAdsorption/desorption of heavy metals onto/from nanoparticles are predictable based on surface area normalized sorption isothermNanomaterials in natural aqueous environments may affect the fate and transport of contaminants substantially