Competitive
Adsorption of Endocrine Disrupting Chemicals on Carbon
Nanotubes
Bo Pan, Ph.D., Baoshan Xing, Ph.D., Department of
Plant, Soil and Insect Sciences, University of
Massachusetts, Amherst, MA
Colloidal
Behavior of Aluminum Oxide Nanoparticles as Affected
by pH and Humic Acid (HA)
Student Presenter
Saikat Ghosh, Department of Plant, Soil, and
Insect Sciences,
University
of
Massachusetts, Amherst, MA
Bo Pan, Department of Plant, Soil, and
Insect Sciences,
University
of
Massachusetts
,
Amherst
,
MA
Hamid Mashayekhi, Department of Plant, Soil, and
Insect Sciences,
University
of
Massachusetts
,
Amherst
,
MA
Prasanta .C. Bhowmik, Department of Plant, Soil, and
Insect Sciences,
University
of
Massachusetts
,
Amherst
,
MA
Baoshan Xing, Department of Plant, Soil, and
Insect Sciences,
University
of
Massachusetts
,
Amherst
,
MA
Influence
of Sonochemical Oxidation on the Dispersion of
Multi-Walled Carbon Nanotubes
Student Presenter
Yingchen Bai, Department of Plant, Soil, and
Insect Sciences,
University
of
Massachusetts
,
Amherst
,
MA
Daohui Lin, Department of Plant, Soil, and
Insect Sciences,
University
of
Massachusetts
,
Amherst
,
MA
Baoshan Xing, Department of Plant, Soil, and
Insect Sciences,
University
of
Massachusetts
,
Amherst
,
MA
Ozone
Nanobubble Treatment of Complex Alkanes
William B. Kerfoot, Kerfoot Technologies,
Mashpee
,
MA
The
Application of Stokesian Principals to Predict
Nanoparticle Fate and Transport in Gaseous and Aqueous
Environments
C. Mackay, AMEC Earth and Environment, Portland, ME
Massachusetts
Government Perspectives on Nanotechnology
Sharon Weber, MA DEP,
Boston,
MA
Competitive
Adsorption of Endocrine Disrupting Chemicals on Carbon
Nanotubes
Bo Pan, Ph.D., Baoshan Xing, Ph.D., Department of
Plant, Soil and Insect Sciences, University of
Massachusetts, Amherst, MA 01003, USA, Tel:
413-545-3862, Email: bpan@psis.umass.edu
Carbon
nanotubes (CNTs) are promising materials in various
areas, and may enter the environment. Studies have
indicated that the adsorption capacities of both
organic and inorganic pollutants are higher on CNTs
than activated carbons. Strong interaction between
pollutants and CNTs indicates that CNTs could also be
used as efficient adsorbents for air and water
treatment and for solid phase extraction. The
mechanism of pollutant adsorption on CNTs is still
unclear. In addition, the present studies on CNTs-pollutant
interaction focus on single solute system. But a
system with the presence of various solutes is common.
Endocrine
disrupting chemicals (EDCs) are a new class of
pollutants, and their main source has been reported to
be municipal sewage. Effective procedure in water
treatment is needed to ensure the safe discharge of
wastewater. This study investigated the adsorption of
EDCs on CNTs in both single solute and bi-solute
systems. Bisphenol A (BPA) and 17a-ethinyl
estradiol (EE2) were chosen as model EDCs with various
solubilities, and their adsorption on single-walled
carbon nanotubes and multi-walled carbon nanotubes was
studied using batch adsorption experiments. The
concentrations of EDCs were analyzed by HPLC with both
UV and fluorescence detectors. High adsorption was
observed for both EDCs on CNTs. The adsorption was
depressed with the presence of a second solute for all
the CNTs in this study, indicating a significant
competition between BPA and EE2. Our results provided
further support for CNTs to be used as adsorbents in
water treatment. The competition between different
chemicals needs to be carefully considered because it
could decrease the removal efficiency of chemicals.
Colloidal
Behavior of Aluminum Oxide Nanoparticles as Affected
by pH and Humic Acid (HA)
Student Presenter
Saikat Ghosh,
Department of Plant, Soil, and Insect Sciences,
University of Massachusetts, Amherst, MA 01003, Tel:
413-545-2739, Email: sghosh@psis.umass.edu
Bo Pan, Department of Plant, Soil, and Insect
Sciences, University of Massachusetts, Amherst, MA,
01003, Tel: 413-545-3862, Email: panbocai@gmail.com
Hamid Mashayekhi, Department of Plant, Soil, and
Insect Sciences, University of Massachusetts, Amherst,
MA 01003, Tel: 413-545-3862, Email:
hamid@psis.umass.edu
Prasanta .C. Bhowmik, Department of Plant, Soil,
and Insect Sciences, University of Massachusetts,
Amherst, MA 01003, Tel: 413-545-5223, Email:
pbhowmik@pssci.umass.edu
Baoshan Xing, Department of Plant, Soil, and
Insect Sciences, University of Massachusetts, Amherst,
MA 01003, Tel: 413-545-5212, Email: bx@pssci.umass.edu
Environmental
fate of the engineered nanoparticles needs to be
studied with great care due to their increasing
exposure in the environment. Colloidal behavior of
aluminum oxide nanoparticles was investigated as a
function of pH and in the presence of two structurally
different humic acids (HA), AHA and HA7, with dynamic
light scattering (DLS) and atomic force microscopy (AFM)
measurements. Aggregation kinetic measurements of the
nanoparticles indicate high colloidal stability in pHs
far away from the point of zero charge (PZC) of the
nanoparticles. The pH dependent aggregate size
measurements clearly show strong aggregation of the
aluminum oxide nanoparticles in the pH range close to
PZC. These results are in accordance with the AFM
data. The strong aggregation of the nanoparticles at
the pH of ZPC or above is strongly inhibited with the
addition of 20 mg/L of both AHA and HA7. However,
aggregation kinetics study of the nanoparticles at pH
4.0 showed strong aggregation with the addition of 5
mg/L HA7, while 5 mg/L AHA did not show any
aggregation. Aggregation kinetics data further
revealed that aluminum oxide nanoparticles tend to
aggregate with increasing concentration of AHA. AFM
imaging manifests the presence of long chain
carbohydrate fractions in HA7, which entangles with
easily diffusible aluminum oxide nanoparticles to form
large aggregate structure. Therefore, this study
elucidates that the colloidal behavior of the aluminum
oxide nanoparticles is dependent on the pH as well as
the physico-chemical properties of the HA present in
the environment.
Influence
of Sonochemical Oxidation on the Dispersion of
Multi-Walled Carbon Nanotubes
Student Presenter
Yingchen Bai,
Department of Plant, Soil and Insect Sciences,
University of Massachusetts, Amherst, Massachusetts
01003, USA, Tel: (413)-545-2739, Fax: (413)- 545-3958
, Email: baiyingchen@126.com
Daohui Lin, Department of Plant, Soil and Insect
Sciences, University of Massachusetts, Amherst,
Massachusetts 01003, USA, Tel: (413)-545-2739, Fax:
(413)- 545-3958 , Email: lindaohui@zju.edu.cn
Baoshan Xing, Department of Plant, Soil and Insect
Sciences, University of Massachusetts, Amherst,
Massachusetts 01003, USA, Tel: (413)-545-5212, Fax:
(413)- 545-3958, Email: bx@pssci.umass.edu
Multi-walled
carbon nanotubes (MWCNTs) can be applied in
electronics, computer, aerospace and chemical industry
due to their outstanding electronic, thermal, and
mechanical properties. MWCNTs could be inevitably
introduced to the environment during production and
application, which have been reported being toxic to
cells, bacteria, rodents, and aquatic organisms. To
modify and disperse the MWCNTs, liquid phase oxidation
of MWCNTs is required. However, little is known about
the biogeochemical behavior of MWCNTs (e.g., mobility
and adsorption), especially the oxidized MWCNTs. To
study the effect of oxidation on MWCNTs suspension,
MWCNTs of different diameters were oxidized using
concentrated sulfuric and nitric acids in an
ultrasonic bath for 1, 2, 4, 8 and 16 h, respectively.
Dispersion of MWCNTs significantly increased with
increasing oxygen content as detected by turbidity
analysis. Transmission electron microscopy images
showed that oxidation could fragment MWCNTs. X-ray
photoelectron spectroscopy and elemental analysis
indicated an increase in oxygen content of MWCNTs with
increasing oxidation time. IR, UV-Visible, Raman, and
fluorescence were employed to examine the MWCNTs
before and after sonochemical oxidation. Stability of
suspended MWCNTs will be also discussed.
Ozone
Nanobubble Treatment of Complex Alkanes
William B. Kerfoot, Kerfoot Technologies, Inc. 766-B
Falmouth Road, Mashpee, MA
02649, USA, Tel: 508-539-3002, Fax: 508-539-3566,
Email: wbkerfoot@kerfoottech.com
Nanobubble
ozone is a nanotechnology breakthrough for groundwater and
soil remediation. Coated
and uncoated ozonated nanobubble treatment systems
substantially increase the effectiveness and versatility
of in-situ chemical oxidation.
The half-life of ozone, with nanobubble gaseous
ozone, compared to dissolved ozone, is significantly
increased as well as its reactivity.
The negatively-charged spheroids
modify the surface tension with water, allowing a higher
density of bubbles at higher concentrations of ozone,
compared to air or nitrogen gas bubbles with comparable
flow. As
gaseous ozone dissolves outwards, the volume of the bubble
enlarges with time as the negative charge dissipates.
With peroxide-coated microbubbles, the negative
charge is retained, but a highly reactive spherical halo
is created as peroxide reacts with the outward-diffusing
dissolved ozone.
At
nanosize, the aqueous solution becomes milky, and the
liquid/gas mixture becomes almost stable as vertical rise
times are less than 1 meter/hour with the smaller
fractions. Solutions
of both nanobubble ozone (Nanozone™) and hydroperoxide-coated
nanobubble ozone (Nanozox™) show exceptional reactivity
with petroleum alkanes, polyaromatic hydrocarbons (PAHs),
and 1,4 dioxane.
A
generator has been developed to produce both forms and
allowed pulsed injection into well screens as well as use
with special points. This
allows the homogenized nanobubble solution to be utilized
like other liquid chemical oxidants in recirculation well
arrangements for groundwater and soil treatment.
The
Application of Stokesian Principals to Predict
Nanoparticle Fate and Transport in
Gaseous and Aqueous Environments
C. Mackay, AMEC Earth and Environment,
15 Franklin St.
,
Portland
,
ME
; 04101, Tel: 207-879-4222, Fax: (207) 879-4223, Email:
chris.mackay@amec.com
Nanomaterials
have presented a unique problem to environmental
scientists. Until
now, the models and paradigms used to predict the behavior
of chemicals in the environment and thereby the potential
for exposure and effect have been firmly rooted in the
principals of solution chemistry such as molarity,
partition, fugacity, etc. However, to evaluate and predict
the behavior of nanomaterials in the environment, new
considerations that take into account particulate behavior
and conditions of surface chemistry need to be added to
the standard model. These include environmental and
material properties such as buoyancy, surface area,
viscosity, charge accumulation, steric factors, and Hakman
forces. Recently, we presented a method for predicting the
mass transport and stability of nanomaterials in the
environment using competitive probability kinetics.
Furthering on this research, this work looks at predictive
methods of determining the probability of reaction (P)
given projected rates of interaction. This is placed in
the context of likely modes of receptor exposure. With
consideration of bioavailability and toxicological potency
and efficacy, this will permit the direct risk evaluation
of potential environmental impacts within the paradigm
currently in use.
Massachusetts
Government Perspectives on Nanotechnology
Sharon Weber,
Massachusetts Department of Environmental Protection (MassDEP),
1 Winter Street, Boston, MA 02108, USA, Tel: 617-556-1190,
Fax: 617-574-6880, Email: sharon.weber@state.ma.us
With
the advent and increasing application of nanotechnology in
research, development, manufacturing and use, a number of
Massachusetts
agencies with diverse interests linked to the use of
nanotechnology began meeting in a Massachusetts
Interagency Nanotechnology Committee in April 2007.
The Departments of Environmental Protection (MassDEP)
and Public Health (DPH), Division of Occupational Safety
(DOS), Toxic Use Reduction Institute (TURI), Offices
of Technical Assistance (OTA) and Business Development (MOBD)
participate to consider nanotechnology issues of concern
to Massachusetts, each keeping in mind their agency’s
mission. By
looking at nanotechnology from multiple angles, the
Interagency Nanotechnology Committee can consider a wide
range of possible impacts related to the varying agency
missions of: ensuring clean air and water and the safe
management of toxics and hazards; promoting public health;
protecting workers’ safety and health; researching,
testing and promoting
alternatives to toxic chemicals used in Massachusetts
industries and communities; assisting implement effective
toxics use reduction and other pollution prevention or
resource conservation activities; and developing
Massachusetts businesses.
As a step in opening a dialogue with stakeholders
and educating the agencies and interested
Massachusetts
parties to a shared level of knowledge, the Interagency
Nanotechnology Committee held an initial workshop, The
Big Picture: Safe Development of Nanotechnology, on
November 15, 2007.
A further goal of the workshop was to identify
potential hazards of the technology, as well as potential
roadblocks to safe development, in order to work with the
nanotechnology sector towards preventing unintended
consequences. The
Interagency Nanotechnology Committee is developing the
agenda for an upcoming follow-on workshop, informed by
input solicited from external stakeholders, and plans to
focus on best management practices for handling
nanotechnology in research and manufacturing settings.
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