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Conference Abstracts (A-F)
Advancing Risk Analysis for Nanomaterials and Nanotechnologies
Jo Anne Shatkin, CLF Ventures, Inc
The rapidly expanding development and use of materials in the nanoscale range has generated new challenges to the application of current risk analysis methods for environmental, health, and safety concerns. The unique properties that may exist for these materials potentially have significant implications for current approaches to the hazard identification, exposure assessment and dose-response components of the traditional risk assessment paradigm that informs risk management decisions, and may confound the accurate assessment of potential risks as well as require changes to the way such risks are communicated to stakeholders and managed by policymakers.
To address these challenges, Jo Anne Shatkin and colleagues organized a workshop on behalf of the Emerging Materials and Nanomaterials Specialty group (EMNMS) of the Society for Risk Analysis: NanoRisk Analysis: Advancing the Science for Nanoscale Material Risk Management, that was held on September 10-11, 2008, in Washington, DC. More than 80 experts from several dozen affiliations participated in the workshop and deliberated on a breadth of issues related to the risk analysis of nanomaterials. Experts in risk analysis, nanotechnology researchers, environmental and health scientists, other key stakeholders and members of the public interested working in or responsible for risk analysis, risk communication, and nanotechnology gathered to identify approaches for risk analysis that assess the unique aspects of nanotechnology and nanomaterials. Five topical white papers were prepared in advance of the workshop, each co-authored by a combination of nanotechnology and risk experts, and were presented on topics of: hazard identification and uncertainty; toxicology; exposure assessment; risk characterization; and risk communication. These papers were vetted in plenary and facilitated deliberative discussion session and will be published, along with other ideas generated during the workshop, as a series of reference papers advancing the science of risk analysis for nanomaterials and nanotechnology. A panel discussion on data gaps and needs for sound decision making vetted views of representatives from international governmental authorities, industry, and non-governmental organizations.
Several themes that emerged from the workshop, such as: engineered nanomaterials may present unique attributes, but share challenges with other emerging environmental substances and technologies in terms of assessing their risks; effective communications for nanotechnology and nanomaterials must explain the complexity and not oversimplify the messaging, while also responding to people’s main concerns. Other workshop outcomes include forming new networks among multidisciplinary experts, junior and international researchers and international governmental, academic and industry leaders in risk analysis and nanotechnology.
Aggregation and Deposition Behavior of Boron
Nanoparticles in Porous Media
Xuyang Liu1, Mahmoud Wazne2, Christos
Christodoulatos1, Kristin L. Jasinkiewicz3. (1) Keck
Geotechnical/Geoenvironmental Laboratory, Center for Environmental Systems,
Stevens Institute of Technology, USA; (2) Department
of Civil, Environmental and Ocean Engineering, Stevens Institute of Technology,
USA; (3) U.S. Army Environmental Technology Division
New kinds of solid fuels and propellants comprised of
nanomaterials are making their way into civilian and military applications yet
the impact of their release on the environment remains largely unknown. One
such material is nano boron, a promising solid fuel and propellant. The fate
and transport of nano boron under various aquatic systems was investigated in
aggregation and deposition experiments. Column experiments were performed to
examine the effects of electrolyte concentration and flow velocity on the
transport of boron nanoparticles under saturated conditions whereas aggregation
tests were conducted to assess the effects of electrolytes on the aggregation
of the boron nanoparticles. Aggregation tests indicated the presence of
different reaction-controlled and diffusion-controlled regimes and yielded
critical coagulation concentrations (CCC) of 200mM, 0.7mM and 1.5 mM for NaCl,
CaCl2, and MgCl2, respectively. Aggregation and
deposition experimental data corresponded well with the classic
Derjaguin-Landau-Verwey-Overbeek (DLVO) model and the filtration model,
respectively. Theoretical calculation indicated that both the primary and
secondary energy minima play important roles in the deposition of nano boron in
sand columns.
Aging of
Iron Nanoparticles in Water: Effects on Structure and Reactivity
Paul G. Tratnyek1, Vaishnavi Sarathy1, James T. Nurmi1, Donald R. Baer2, Chanlan Chun3, R. Lee Penn3, Eric J. Reardon4.
(1) Division of Environmental and Biomolecular Systems, Oregon Health and
Science University, USA; (2) Environmental Molecular Sciences Laboratory, Pacific
Northwest National Laboratory, USA; (3) Department of
Chemistry, University of Minnesota; USA (4) Department of Geology,
University of Waterloo, Canada
Aging (or longevity) and transport in aqueous media remain the most important and potentially limiting factors in the use of nano-Fe0 to reduce contaminants in groundwater remediation. We have investigated the short- and long-term aging of FeH2 (Toda RNIP-10DS, a nano-sized iron produced by reduction of iron oxides in a H2 atmosphere to produce a zero-valent iron core and a magnetite shell) in water and the resulting effects on the chemistry of the oxide-shell and reactivity of the particles with water (i.e., hydrogen production) and carbon tetrachloride (CT).
For short- and long-term aging effects, we used preparations of FeH2 that had not been exposed to water (FeH2(D)), and one that had been in slurry for approximately a year (FeH2(W)). We studied the aging of these materials in terms of: (i) the structure of the iron particles characterized using spectroscopy and microscopy (XPS, XRD and TEM); (ii) the Fe0-content and rate of H2 production by reaction of Fe0 with H2O, (iii) the kinetics and pathway of reaction with CT; and (iv) changes in corrosion potential of the iron-oxide particles using electrochemical experiments.
While the Fe0-content gave a monotonic decay, as has been reported previously by others, most of the other properties show more complex behavior with a period between 0 and a few days exposure to water where the FeH2(D) becomes more reactive followed by a gradual decline in reactivity of the next few hundred days. This can be seen in the kinetics of CT reduction, yield of chloroform from CT, open circuit potential, and hydrogen evolution rate. Taken together, they suggest depassivation of the oxide film on FeH2(D) soon after immersion, followed by reformation of a passivating oxide shell (but never complete passivation until the Fe0 is entirely depleted, which was not achieved for the times periods of our study ). The behavior of FeH2(W) is consistent with extrapolations from the aged FeH2(D) data.
These observations have implications for laboratory- and field-scale applications of nano-Fe0. In particular, they suggest that the results from typical laboratory batch experiments may be more applicable to field-scale applications for source zone treatment, because both involve relatively brief periods of reaction. While FeH2 aged over longer time periods becomes much less reactive, it has the advantage of acquiring properties that are relatively stable over weeks or even months.
An Integrated Approach
Toward Understanding the Environmental Fate, Transport, Toxicity and
Occupational Health Hazards of Metal and Metal Oxide Nanomaterials
Vicki Grassian, Department of Chemistry, University of Iowa, USA
Nanoparticles, the primary building blocks of many nanomaterials, may become suspended in air or get into water systems, e.g. drinking water systems, ground water systems, estuaries and lakes etc. Therefore, manufactured nanoparticles can become a component of the air we breathe or the water we drink. One important issue in understanding the environmental fate, transport, toxicity and occupational health hazards of nanoparticles is in characterizing the nature and state of nanoparticles in air, water or in vivo. For the nanomaterials of interest in these studies, metal oxide and metal nanoparticles, it can be asked: (i) will metal oxide and metal nanoparticles be present in air or water as isolated particles or in the form of aggregates?; (ii) will metal oxide and metal nanoparticles dissolve in aqueous solution or in vivo?; and (iii) under what conditions will metal oxide and metal nanoparticles aggregate or dissolve? As the size regime will be very different depending on the state of the nanoparticles, as dissolved ions, isolated nanoparticles or nanoparticle aggregates, these questions are important to address as it impacts the size regime that needs to be considered or modeled in for example, environmental transport or lung deposition models. Furthermore, the effect on biological systems including nanoparticle-biological interactions and toxicity will depend on the state of the nanoparticles. In the studies discussed here an integrated approach is used to address these questions and issues. The approach combines state-of-the-art characterization of the bulk and surface properties of nanoparticles, studies of the physicochemical properties of nanoparticles which include aggregation and dissolution in laboratory and field studies along with toxicity studies. This integrated approach is needed in order to better understand the environmental fate, transport, toxicity and occupational health hazards of metal and metal oxide nanomaterials.
Application of Nanoparticles for Environmental Remediation
and Challenges
Sandip Chattopadhyay, TetraTech/EM, Inc., USA
Balancing energy demands while protecting the environment is a major challenge. As a set of fundamental technologies that cuts across all industries, nano-particles and nano-technology can address some of environmental problem in a wide variety of ways. Stronger, lighter-weight materials in transportation can reduce fuel use, small amount of nano-particles can effectively remove various contaminants of concern, nano-structured fibers reduce staining and therefore laundering, and low-cost nano-sensors will make pollution monitoring affordable. In the longer term, manufacturing processes using productive nano-systems should be able to build our products with little if any waste. Nanotechnology will help to solve the dilemma of energy needs and limited planetary resources through more efficient generation, storage and distribution. Nanotechnology and application of nano-particles are emerging and rapidly growing field whose dynamics and prospects pose many great challenges not only to scientists and engineers but also to society at large. This presentation will include some of the state-of-the-art technologies, philosophical, ethical, and sociological reflection on nanotechnology. It will explore the ethical issues of nanotechnology, its impact on human, environmental, and social conditions, and the options for reasonable risk management. It will examine the public discourse on nanotechnology and its related visions and provides both lessons from the past and outlooks for the future.
Arsenic Adsorption and As (III)
Oxidation on TiO2 Nanoparticles: Macroscopic and Spectroscopic
Investigations
Gautham Jegadeesan1, Souhail R. Al-Abed2, Hyeok Choi2, Kirk G. Scheckel2. (1) Pegasus Technical
Services, Inc., USA; (2) U.S. EPA National Risk Management Research Laboratory
Engineered nanoparticles (NPs) (particle sizes ranging from 1-100 nm) have unique physical and chemical properties that differ fundamentally from their macro-sized counterparts. In addition to their smaller particle size, nanoparticles possess unique characteristics such as large surface to volume ratio and higher chemical reactivity, which are conducive for their application in environmental remediation, especially adsorption of target contaminants. In this study, we examine the sorption of arsenite (As (III)) and arsenate (As (V)) on TiO2 nanoparticles, produced via sol-gel synthesis, using a combination of macroscopic and spectroscopic investigations. The synthesis of TiO2 particles, both amorphous and crystalline forms, was achieved via controlled sol-gel method at room temperature (25 °C with no calcination), and then calcined at high temperatures (250-600 °C) to control their physicochemical properties. Relative crystallinity of the TiO2 particles was observed to increase with increasing calcination temperature, while surface area decreased with temperature. Arsenic adsorption envelopes indicated that pH was not a deterrent for As (III) sorption on the amorphous TiO2, with more than 90% removal observed for all pH. However, As (V) removal decreased significantly beyond pH 7.0. Macroscopic investigations on arsenic sorption indicated that maximum As (V) coverage on both crystalline and amorphous TiO2 occurred in the pH range of 3.8-6.5. The effect of pH on As (III) sorption onto amorphous TiO2 was less pronounced, in comparison to crystalline TiO2. XAS analysis provided evidence of partial As (III) oxidation on amorphous TiO2 and not on the crystalline TiO2, likely due to the surface chemistry of the particles and the presence/ absence of surface hydroxyl groups. Electrophoretic mobility measurements and XAS analysis indicated that As (III) and As (V) form binuclear bidentate inner-sphere complexes with amorphous. As (III) and As (V) sorption isotherms indicated that sorption capacities of the different TiO2 polymorphs were dependent on the sorption site density, surface area (particle size) and crystalline structure. When surface coverages were normalized to specific surface areas, crystalline TiO2 appeared to exhibit higher capacities. However, a reverse trend was observed when arsenic sorption was expressed on a per unit mass basis. The results suggested that high surface area amorphous TiO2 particles could dramatically increase both As (III) and As (V) sorption capacities in drinking water treatment systems.
Assessing Transport of Gold Nanoparticles and Bacteria in
Porous Media Using X-ray CT Scanning
Subhasis Ghoshal1, Nathalie Tufenkji2 and Greg McKenna1. (1) Department of Civil Engineering and
Applied Mechanics, McGill University, Canada;
(2) Department of Chemical Engineering, McGill University, Canada
X-ray CT scanning is used in medical research for non-invasive tracking of nanoparticle tracers or drug delivery agents in animal and human bodies. We have recently determined that a medical X-ray CT scanner can be used to quantitatively determine the spatial distribution of gold and other metallic nanoparticles in environmental porous media. The detection threshold for gold nanoparticles in packed quartz sand columns were in the range of 1010 particles/mL, and the CT number signal increased linearly with particle concentration. The ability for non-invasive detection of gold nanoparticles using X-ray CT was used to develop a technique for assessing bacterial density distributions in a saturated porous media column by labeling bacterial cells with gold nanoparticles.
The transport of bacteria in granular porous media is important to many environmental applications such as bioremediation and pathogen transport. Traditionally, the fate of bacteria in porous media has been studied using bench-scale column experiments while monitoring the suspended effluent concentration. Determining the spatial distribution of deposited bacteria in the column using a noninvasive and non-destructive technique has the potential to improve the understanding of some transport processes for bacteria.
Bacteria cells are generally not detectable in water saturated columns because their X-ray attenuation properties are similar to water. Nano-sized gold particles were synthesized in the presence of cetyltrimethylammonium bromide (CTAB) and were attached to Bacillus subtilis cells forming a monolayer of gold coverage at the bacteria surface. The gold-labeled bacteria cells were injected into the saturated porous media in traditional column experiments containing both homogeneous and heterogeneous packed quartz sand. Gold-labeled cells were detectable during CT scanning at concentrations of 3 x 107 cells/mL when injected into water-saturated sand columns and thus allowed for the determination of areas of high deposition in packed sand columns. CT scanning permitted the non-invasive calculation of porosity in situ as well as observing changes in deposition behavior due to sand heterogeneities such as the accumulation of gold-labeled bacteria at the interface between coarse and fine sands. This knowledge on spatial distribution of bacterial density distributions could not be otherwise determined from analyses of the effluent concentrations or without sampling the porous media destructively.
The research demonstrates a new technique for assessing transport of nanoparticles and nano-particle tagged colloidal particles in environmental porous media.
Bioavailability and Toxicity of Nickel in Metallic
Nanoparticles
Agnes Kane1, Ashley
Smith1, Xinyuan Liu1, Kevin McNeil1, Robert
Hurt2
(1) Department of Pathology and
Laboratory Medicine, Brown University, USA (2) Institute for Molecular and
Nanoscale Innovation (IMNI), Brown University, USA
Catalytic routes are used for arc synthesis of commercial carbon nanotubes and nickel is a common metallic catalyst. Nickel and nickel oxide nanoparticles are also used commercially in nanomagnetic devices, batteries, fuel cells, catalytic converters, and solar cells. Nickel is classified as a known human carcinogen and is a common industrial and environmental pollutant. Recent studies have shown that metallic nickel nanoparticles induce greater acute lung toxicity and inflammation than micron-sized nickel particles following intratracheal instillation in rodents that has been attributed to elevated surface area and reactivity of nanoparticles. Lung epithelial cells are a primary target for nickel-induced toxicity following inhalation of poorly soluble nickel particles. The proposed mechanism responsible for nickel toxicity is phagocytosis or endocytosis of particulate nickel by target cells. It is postulated that intracellular release of Ni (II) ions from the acidic environment of endosomes could interact with cytoplasmic or nuclear protein targets. In acellular assays, Ni (II) ions were mobilized from metallic nickel nanoparticles and mobilization was enhanced at acidic pH. Human lung epithelial cells (H460) internalized metallic nickel nanoparticles within 24 hours in vitro. Intracellular mobilization of Ni (II) ions was greater from metallic nanoparticles than from micron-sized particles. Metallic nickel nanoparticles also induced dose-dependent toxicity in parallel with intracellular Ni (II) ion mobilization as assessed by morphology, Syto-10/ethidium homodimer viability assay, and Pico Green fluorescence to quantitative cellular DNA. Metallic nickel nanoparticles also demonstrated higher surface reactivity than micron-sized nickel particles in a cell-free assay for oxidation of 2’, 7’-dichlorofluorescein (DCFH). These experiments support a role for elevated mobilization of Ni (II) ions and surface reactivity of metallic nickel nanoparticles in the enhanced toxicity of these metallic nanomaterials. This research was supported by grants from the National Institutes of Health (P42 ES013550) and the National Science Foundation (NSF DMI-05066).
Can Nanoscale Particles Affect Plant Growth – Alfalfa
Case Study
Sylvia Chan-Remillard1,2,3, Larry Kapustka1,
Stephen Goudey1,2 (1) Golder Associates Ltd., Canada; (2) HydroQual Laboratories Ltd., Canada; (3) Alberta Ingenuity Fund, Canada
Nanotechnology is a phenomenon that has the potential to change existing technologies and the ability to create new technologies that were previously unattainable. However, along with this potential is the added responsibility to understand and manage the hazards and risk associated with nanotechnology exposure. Regardless of the intended end use of nanotechnology, the environment will become the ultimate recipient of the products at the end of their life cycle. The impact of these nanoscale particles on the environment is not very well understood. What is the fate of these particles once they are in the environment? Do they biotransform, biomagnify or bioaccumulate? Or do they simply react with organic matter and become benign? Are these particles toxic to different ecological receptors? Currently very little data exists on the fate and effects of these particles once they are in the environment. Ecological receptors may be exposed to nanoscale particles in freshwater, saltwater, soil or sediment. Aquatic studies are beginning to demonstrate that nanoscale particle toxicity is highly organism and nanoscale particle dependent. However, within the terrestrial compartment there is still very little information on the toxicity of nanoscale particles on receptor organisms. We examined the effect several nanoscale particles had on plants using alfalfa inoculated with rhizobium. Measurement endpoints used were root growth, shoot elongation and nodule formation. The results of this study will be discussed. We will also discuss the development of a life cycle based risk assessment framework in the context of managing environmental risks associated with nanotechnology.
Carbon Nanoparticle Exposure Alters Protein Expression
and Cell Function in Mouse Renal Principal Cells
F.A. Witzmann1, A.D. Amos2, X.
Lai1, B.L. Blazer-Yost2. (1)Cellular & Integrative
Physiology, Indiana University School of Medicine, USA (2) Biology, Indiana Univ ersity-Purdue University, USA
Manufactured carbon nanoparticles (CNP) present in industrial environments can enter the human body via the skin, lungs, and intestine, be dispersed via the blood stream, and may affect many biological systems, including the kidneys. To assess the effects of CNP exposure on renal epithelial cells, 3 types of CNP, single-wall carbon nanotubes (SWCNT), multi-wall carbon nanotubes (MWCNT), and fullerenes (4-200 µg/cm2, 48 hrs) were applied to mouse principal cells of the kidney cortical collecting duct (mpkCCDcl4) and functional changes determined via electrophysiology. The mpkCCDcl4 cells grow to form a confluent monolayer which simulates a barrier epithelial function and hormone responsiveness found in vivo in renal collecting ducts. These cells are of particular interest because they are responsible for much of the hormonally-regulated ion transport in the kidney. If the CNP exposure functionally alters these cells, salt homeostasis could be modulated, resulting in changes in blood pressure. We hypothesize that CNP exposure alters mpkCCDcl4 cells resulting in decreased viability and/or abnormal normal cellular function. Accordingly, studies were conducted to determine functional, structural and proteomic changes induced by CNP exposure. CNP were prepared by two different procedures: ethanol-sterilization and sonication-suspension. High concentrations of ethanol-sterilized CNP treated cells exhibited significant decreases in transepithelial resistance (TEER), increased basal Na+ transport, and changes in hormone-stimulated ion transport. Sonication-suspended CNP-treated cells showed masked effects, though trends of decreased TEER and altered ion transport were still observed. To determine CNP-induced structural changes, confluent cells were incubated with sonication-suspended CNP. Actin filaments, proliferating nuclei, and total cell nuclei were visualized in fixed cells. Cultures treated chronically (7 days) with CNP (5 µg/cm2, thrice weekly) showed an increase in large, multinucleated cells. Cultures treated acutely with CNP (21 µg/cm2, 48 hrs) revealed CNP agglomerates surrounded by proliferating nuclei, increased actin filaments and large multinucleated cells. Differential protein expression analysis by 2-DE and Label-free Quantitative Mass Spectrometry revealed changes in numerous proteins, including intra- and extra-cellular membrane-associated proteins stathmin-like 2 and enolase and myotubularin related protein 9, gap junction alpha-8 protein coiled-coil domain-containing protein 44, zona pellucida glycoprotein 4, olfactory receptor 586, phosphomannomutase 2, RAN binding protein 1, and actin. These results indicate a significant impact of CNP on renal epithelial cell structure and function and emphasize the need for expanded studies of CNP effects on these and other barrier epithelial cells. Supported by NIGMS R01GM085218-01, AFOSR Grant FA9550-06-1-0083, and IUPUI Undergraduate Research Opportunities Program.
Classification of Nanomaterials: Use of Multi-Criteria Decision Analysis
Igor Linkov1, Tommi Tervonen2, José Rui Figueira2, Jeffery Steevens1, Mark Chappell1. (1) U.S. Army Engineer Research and Development Center; (2) Technical University, Spain
There is rapidly growing interest by regulatory agencies and stakeholders in the potential risks associated with nanomaterials throughout the different stages of products’ life cycle (e.g., development, production, use and disposal). Risk assessment methods and tools developed and applied to chemical and biological agents may not be readily adaptable for nanomaterials because of the current uncertainty in identifying the relevant physico-chemical and biological properties that adequately describe the materials. Such uncertainty is further driven by the substantial variations in the properties of the original material because of the variable manufacturing processes employed in nanomaterial production. We propose a decision support system for classifying nanomaterials into different risk categories. The classification system is based on a set of performance metrics that measure both the toxicity and physico-chemical characteristics of the original materials, as well as the expected environmental impacts through the product life cycle. The stochastic multicriteria acceptability analysis (SMAA-TRI), a formal decision analysis method, was used as the foundation for this task. This method allowed us to cluster various nanomaterials in different risk categories based on our current knowledge of nanomaterials’ physico-chemical characteristics, variation in produced material, and expert estimates. SMAA-TRI used Monte Carlo simulations to explore all feasible values for weights, criteria measurements, and other model parameters to assess the robustness of nanomaterial grouping for risk management purposes.
Comprehensive Investigations on Nano-Size ZVI for Mending
an Existing Permeable Reactive Barrier in the 100-D Area at the Hanford Site
Marek H. Zaluski1, Gary Wyss1,
Adam Logar1, Nick Jaynes1, Martin Foote1,
Gilbert M. Zemansky1, Kenneth R. Manchester1, Steve
Antonioli1, Mary Ann Harrington-Baker1, David Reichhardt2,
Mark Ewanic3, Scott Petersen4. (1) MSE Technology
Applications, USA; (2) Montana Tech, USA; (3) Montana Department of
Environmental Quality, USA; (4) Fluor Hanford, USA
MSE Technology Applications, Inc. has conducted investigations associated with injection of nano-size zero-valent iron (nZVI) into the subsurface at the 100-D Area at the U.S. Department of Energy (DOE) Hanford Site in Washington State. The purpose of this work was to demonstrate the feasibility of using nZVI to repair portions of the In Situ Redox Manipulation (ISRM) barrier located in the 100-D Area of the Hanford Site that was installed to intercept a hexavalent chromium plume moving towards the Columbia River.
The investigations included the following phases:
- an inventory of commercially available nZVIs that identified 30 materials produced by 16 manufacturers;
- laboratory preliminary screening of 7 nZVI materials that were deemed to be most promising for ISRM barrier mending;
- geochemical laboratory testing of Polymetallix and RNIP-M2 nZVIs that were selected through earlier preliminary screening;
- flow cell and sand tank testing of injectibility of Polymetallix and RNIP-M2 nZVIs into saturated sand; and
- predictive computer modeling of post-injection distribution of nZVI in the Ringold aquifer.
The paper includes a succinct description of techniques used and the results obtained for each phase of these comprehensive investigations, which led to identification of RNIP-M2 as the most appropriate nZVI material for mending the ISRM barrier. A field pilot test of RNIP-M2 emplacement in the Ringold aquifer through one of the ISRM injection wells will take place in July 2008.
This work was conducted through the support of Fluor Hanford under Contract Number 30994.
Conjugates of Enzyme-Magnetic Nanoparticles for Water Remediation
You Qiang1, Andrzej Paszczynski 2, Amit Sharma1, Ryan Souza1. (1) Department of Physics and Environmental Science Program, University of Idaho, USA; (2) Environmental Biotechnology Institute and Department of Microbiology Molecular Biology and Biochemistry, University of Idaho, USA
Enzymes are proteins that are utilized as biocatalysts in bioremediation. A concern in environmental applications of enzymes is their short lifetime and poor stability. Enzymes lose their activity due to denaturation, which render their stability and a shorter lifetime. An effective way to increase the stability, longevity, and reusability of the enzymes is to attach them to the solid surface particularly to the surface of magnetic nanoparticles. If enzymes are attached to the magnetic iron nanoparticles, we can easily separate the enzymes from reactants or products by applying a magnetic field. With this aim, two different catabolic enzymes, trypsin and peroxidase, were attached to uniform core-shell magnetic nanoparticles (MNP’s) produced in our laboratory. Our study indicates that the lifetime and activity of enzymes increases dramatically from a few hours to weeks and that enzyme-MNP conjugates are more stable, efficient, and economical. TEM images show that the enzyme-MNP conjugate forms nano-rings secondary structure in water that prevents the enzyme molecules from denature and self-digest. This results in an increased functional lifetime of the enzymes. Because of the high magnetization (larger than 150 emu/g) of our core-shell MNPs, enzyme-MNP conjugates can be suspended in magnetic field, making enzymes-MNP conjugate catalytically more efficient than enzyme immobilized to the “macro” surface.
This work is supported by grants of DOE-EPSCoR (DE-FG02-04ER46142), and DOE-BES (DE-FG02-06ER15777).
Current, Emerging, and Future
Technologies for Sensing the Environment
Dermot Diamond, Queen’s University, Ireland
Around the world, the ability to monitor environmental status is now a priority for many countries. The prioritization of environmental monitoring has been driven by a number of factors including climate change, recognition of the importance of the environment for sustainable economics, linking of environmental monitoring with threat detection and the implementation of an array of European Union environmental directives by Member States.
This paper reviews current technologies that are used for environmental monitoring, and presents emerging technologies that will dramatically improve our ability to obtain spatially distributed, real-time data about key indicators of environmental quality at specific locations. Futuristic approaches to environmental monitoring that employ fundamental breakthroughs in materials science to revolutionize the way we monitor our environment will also be considered. In particular, approaches employing biomimetic and ‘adaptive’/’stimuli-responsive’ materials will be highlighted, as these could play an important role in the realization of small, low power, low cost, autonomous sensing and communications platforms that could form the building blocks of the much vaunted environmental ‘sensor web’.
The author would like to acknowledge funding from Science Foundation Ireland under the CLARITY CSET initiative, and from the Irish Marine Institute and Environmental Protection Agency, through the Smartcoast and other project awards.
References
Integration of Analytical Measurements and Wireless Communications – Current Issues and Future Strategies, Dermot Diamond, King Tong Lau, Sarah Brady and John Cleary, Talanta 72 (2008) accepted for publication.
Wireless Sensor Networks and Chemo/Bio-Sensing, Dermot Diamond, Shirley Coyle, Silvia Scarmagnani and Jer Hayes, Chemical Reviews, 108 Issue: 2 (2008) 652-679.
Internet-scale Sensing: Are Biomimetic Approaches the Answer?, Sonia Ramirez-Garcia and Dermot Diamond, Journal of Intelligent Material Systems and Structures, 18 (2) (2007) 159-164.
Development of Disposable Microfabricated
Chip Sensor Using Nano Bead Packing Method to Measure Nitrogenous
Compounds
Am Jang1, Kang K. Lee2, Zhiwei
Zou2, Chong H. Ahn2, and Paul L. Bishop1. (1) Department
of Civil and Environment Engineering, University of Cincinnati, USA; (2) Microsystems and BioMEMS Laboratory, Department of Electrical and Computer Engineering, University of Cincinnati, USA
The determination of nitrogenous compounds in a variety of matrices, especially, in surface and ground water and during water treatment, is of great importance. Traditional monitoring is accomplished by invasively collecting samples in the field and transporting them to centralized laboratories for analyses. Unfortunately, since their constituent speciation can change quickly as a result of chemical, biological and physical reactions, the long time delays associated with this procedure are frequently unacceptable. Thus, one of the best preventive measures is to rapidly determine the environmental constituents on-site. Environmental constituents can be commonly determined by ion chromatography (IC), potentiometric methods or spectrophotometric methods. When these methods are considered for application on-site, however, they have a number of disadvantages: they require highly trained technicians due to the complicated procedures and maintenance of the expensive equipment; currently available equipment is so large in size that it can usually only be used in the laboratory; the pre-treatment and assay procedures are complex and lengthy, which is not efficient for fast determination of environmental constituents; and they require large volumes of reagents and samples. Consequently, these reasons have prompted the need to develop sensitive, selective, portable and rapid methods to determine environmental constituents in water.
The use of electrochemistry for detection is most promising because of its reliability, selectivity, compactness, low cost, simple structure, high sensing performance and compatibility with Micro Electro Mechanical Systems (MEMS) manufacturing techniques. In this research, we have adopted and optimized a self-assembly technique to fabricate a crystalline micro/nano sphere column in a polymer lab-on-a-chip (LOC). Therefore, the goal of this research is to develop an on-site monitoring sensor technology that protects the public and the environment from toxic nitrogenous compounds that can cause many environmental water problems.
Differential Reactivity of nZVI towards Lindane and
Implications for QA/QC and Field-Scale Use
Daniel W. Elliott, Ph.D.1, Wei-xian Zhang,
Ph.D. 2, (1) Geosyntec Consultants, USA; Department of Civil &
Environmental Engineering, Lehigh University, USA
Since the initial field demonstration of nanoscale zero-valent iron (nZVI) as a potential groundwater remediation tool in 2000, the emerging technology has received considerable attention among academic researchers, regulators, and the regulated community alike. A wide array of manufacturing methodologies currently exists to produce nZVI and various other bimetallic and kindred products for the environmental remediation marketplace. However, evidence from recent peer-reviewed reports and from applied field studies suggests a very wide range of nZVI performance which can be at least partly attributed to the intrinsic properties of the iron itself. Because nZVI is a reactive material, its fundamental properties can change over time. Other factors might include differing production methods, aging of the material, or batch to batch variability. This is particularly true for nZVI products stored and shipped as aqueous slurries or under other liquids potentially reactive towards iron. One of the key challenges in the environmental remediation marketplace is to objectively assess the performance of the various nZVI products given the relative lack of quality assurance and quality control (QA/QC) protocols and data from the manufacturers. In this presentation, the data from batch degradation studies of high concentrations of gamma-hexachlorocyclohexane (g-HCH) in 95% ethanol exposed to different nZVI materials are used to illustrate the potentially dramatic impacts of varying iron reactivity and the need for development of more standardized QA/QC protocols for nanoscale iron products. HCH (C6H6Cl6) is a well studied pesticide formerly in ubiquitous use around the world from the 1940s into the 1990s. HCH was deployed in various technical grade isomeric mixtures and as high purity g-HCH, better known as lindane, which was the isomer that exhibited the most pesticidinal efficacy. The structure of lindane played an important role in shedding light on the issue of varying nZVI reactivity and helped to underscore the need for better QA/QC protocols to be developed for the iron used in environmental remediation applications. Specific QA/QC parameters recommended include pH/ORP profile, particle size distribution, specific surface area, zeta potential/isoelectric point, and batch contaminant degradation test. With this data, the consulting, regulated, and regulator communities will have a better means of assessing nZVI reactivity and performance potential prior to use in the field.
Effects of Particle Size on the Kinetics of Degradation
of Contaminants
Paul G. Tratnyek1,
Vaishnavi Sarathy1, Jae-Hun Kim2, Yoon-Seok Chang2, and Bumhan Bae3 (1) Department of
Environmental and Biomolecular Systems Oregon Health and Science University,
USA; (2) School of Environmental Science and Engineering POSTECH, South Korea; (3) Department of Civil and Environmental Engineering Kyungwon University, South Korea
There are many reports suggesting that nano-sized particles exhibit greater reactivity with reducible contaminants than micro-sized particles of the same materials. However, most of these reports are preliminary in that they leave a host of potentially significant (and often challenging) material or process variables either uncontrolled or unresolved. In particular, many studies do not clearly distinguish between mass-normalized and surface-area-normalized rate constants, or do not use robust methods for calculating the latter from the former. To take such factors into account when making generalizations about relative reaction rates—without a mechanistic kinetic model more detailed than any that is current available for this system—an alternative approach is needed.
The approach that we have found to be particularly useful is a log-log plot of surface area normalized rate constants (kSA, L m-2 hr-1) vs. mass normalized rate constants (kM, L g-1 hr-1) where the two types of rate constants are related by the specific surface area of the particles (as, m2 g-1) according to the equation: log kSA = log kM – log as.
Using plots of log kSA vs. log kM for reduction of carbon tetrachloride (CCl4) by zero-valent iron, we have show that nanoparticles generally have larger kMs, but kSAs are similar for nano- and micro-sized iron. In other words, there is no “intrinsic” nano-size effect on the rate of this reaction. The analysis also shows that kM and kSA are both smaller for low-purity iron than high purity iron (nano or micro). This suggests that purity is more important than (nano) size in determining the “intrinsic” reactivity of Fe0 with CCl4.
Most data on the kinetics of contaminant reactions with particles are adequate to determine kM and kSA, so they can be included on log kSA vs. log kM plots, and these plots can be used for a wide variety of comparisons. Several examples will be provided, addressing issues such as: (i) the nano-size effect on the reactivity of Fe0 with chlorinated ethenes, energetics (explosives: TNT, RDX, etc.), and chlorinated aromatics (PCBs, Dioxins, etc.); (ii) the particle size effects on reduction by other zero-valent metals; and (iii) the relative reactivity of nanoparticulate reductants that contain only FeII and those that also contain Fe0.
Effects of Solution Chemistry and Characteristics of Nanostructured
Ceramic Membrane on NOM Fouling in a Hybrid Ozonation-UF Water Treatment System
Volodymyr V. Tarabara1, Jeonghwan Kim1,
Simon H. R. Davies1, Melissa J. Baumann2, Susan J. Masten3.
(1) Department of Civil and Environmental Engineering, Michigan State
University, USA; (2) Department of Chemical Engineering and Materials Science,
Michigan State University, USA; (3) Department of Civil Engineering, McMaster
University, Canada
Recent advances in nanotechnology have expanded the range of methods available to environmental scientists and engineers to purify water and bring its quality to drinking water standards. We have demonstrated the potential of combination of metal oxide nanoparticles with membrane technology to catalyze important oxidation reactions such as ozonation. The superior catalytic activity of nano-sized metal oxides is due to the unique chemistry and nanoscale structure of their surface as well as the very high surface area. These novel materials are also of interest in membrane technology as the potential solution to the long standing problem of membrane fouling due to natural organic materials (NOM). Organic molecules such as NOM are also of especial concern because they are abundant in surface water supplies and react with chlorine, a common water disinfectant, to form carcinogenic chlorinated compounds.
In this study, we investigated the effects of solution pH and calcium ions on the interactions between NOM and the nano-structured Titania surface of ceramic membrane used as a component of a hybrid ozonation-ultrafiltration water treatment system. Interactions between NOM and ceramic membrane were studied in a batch reactor to record adsorption isotherm as well as during the operation of the hybrid system. Both calcium and pH were found to mediate the adsorption process by altering the charge of the membrane surface and the NOM molecules; however the observed adsorption behavior could not be described based on the electrostatic theory alone. We have also studied the heterogeneous catalytic ozonation with manganese dioxide nanoparticles (MnO2) known as effective metal oxide for ozone decomposition. The MnO2 metal oxides were synthesized and imbedded on the ceramic membrane surface by a layer-by-layer method. Our results indicated that the catalytic efficiency of MnO2 coated membrane should be enhanced by increasing the number of coating layer rather than adjusting sintering temperature.
Effects of Surface
Functionalization on Carbon Nanotube Interactions with Murine Macrophages and
Hepatocytes
Agnes Kane1 Annette von dem Bussche1,
Aihui Yan2, Vanesa Sanchez, Robert Hurt2. (1) Department
of Pathology and Laboratory Medicine, Brown University, USA (2) Division of Engineering, Brown University, USA
Carbon nanotubes have been functionalized with surface targeting ligands for drug delivery applications. Functionalized carbon nanotubes delivered by intravenous injection have been reported to be taken up by the reticuloendothelial system in the liver, spleen, and bone marrow followed by excretion into the bile and urine (Liu et al., PNAS, 2008). Therefore, likely cellular targets for potential adverse effects of carbon nanotubes include macrophages and hepatocytes. Hydrophobic commercial multi-wall carbon nanotubes (MWCNTS) were modified by two covalent functionalization schemes (negative aryl-sulfonate groups and positive aryl-amine groups). Covalently functionalized MWCNTs were internalized by these murine target cells and induced dose-dependent toxicity in an immortalized murine liver cell line. Carbon nanobeads were internalized but were nontoxic to these murine target cells. Toxicity of commercial carbon nanotubes has been linked with oxidative stress that was exacerbated by vitamin E deficiency (Shvedova et al., Toxicol. Appl. Pharmacol., 2007). Non-covalent coating of MWCNTs with a synthetic amphiphilic vitamin E derivative enhanced dispersion in aqueous phases and cell culture medium (Yan et al., Carbon, 2007). We predict that this non-covalent surface modification of MWCNTs will enhance intracellular delivery with decreased toxicity.
This research was supported by grants from the National Institutes of Health (R01 ES016178, T32 ES07272, and P42 ES013550) and the National Science Foundation (NSF DMI-05066).
Environmental Applications of Nanocrystalline Metal
Oxides
David Jones, NanoScale Corporation, USA
NanoActive materials are metal oxide aggregates that possess very large surface areas, defect-rich morphology, large porosities, and small crystallite sizes. This combination of properties results in extremely high reactivity including both enhanced reaction kinetics and large capacities. These materials have shown utility in both consumer and military applications. Of particular importance is the destructive adsorption of various toxic and odorous compounds, air and water filtration, as well as removal of heavy metals and sulfur species. In addition, novel metal oxide formulations with the unique ability to neutralize toxic chemicals as well as biological organisms were developed. Several of oxides have been shown to possess considerable biocidal activity against the opportunistic pathogens Staphylococcus aureus and Pseudomonas aeruginosa with applications in antimicrobial paints and coatings. Consumer products based on these materials include chemical spill control systems and odor neutralization systems.
Environmental Applications of Nanocrystalline Zeolites
Sarah C. Larsen, University of Iowa, USA
Nanocrystalline zeolites (with crystal sizes of less than 50 nm) are versatile, porous nanomaterials with potential applications as adsorbents for water contaminants or as environmental catalysts. We have developed efficient, synthetic methods for the preparation of high quality, monodisperse, nano-crystalline (<50 nm) zeolites such as silicalite, ZSM-5 or faujasite. The advantages of nanocrystalline zeolites include increased surface area, improved optical properties (transparency), improved diffusion/mass transfer properties and the ability to form hierarchical zeolite structures. The large external and internal surface areas lead to unique surface chemistry relative to more conventional microcrystalline zeolite materials. The external surface of nanocrystalline zeolites can be functionalized with organosilanes resulting in multifunctional zeolite materials.
The nanocrystalline zeolite external surface can be functionalized with an organosilane, such as aminopropyltriethoxysilane (APTES), forming an amine functionalized surface. Under acidic conditions, aqueous metals, such as Cr6+ and Cu2+, can be effectively adsorbed onto the surface of the APTES functionalized nanocrystalline silicalite. While adsorption is useful, it is sometimes more desirable to reduce toxic metals such as Cr6+ to less toxic forms such as Cr3+. The photoreduction of adsorbed Cr6+to Cr3+ was investigated using encapsulated iron-exchanged hollow zeolites. The iron-exchanged zeolites were active for the photoreduction and the iron was resistant to leaching. Other bifunctional nanocrystalline zeolites are also being evaluated as adsorbents for contaminated water.
Nanocrystalline zeolites have potential utility as improved emission abatement catalysts. The reactivity of nanocrystalline faujasite zeolites for the selective catalytic reduction (SCR) of NO with hydrocarbon or ammonia reductants was investigated. External surface sites on the zeolite were identified and associated with SCR reactivity, thus demonstrating the enhanced activity of nanocrystalline zeolites.
Environmental Pollution Sensing and Monitoring Using Nano-enabled Sensors
A. Vaseashta1 and O. P. Roberts2 (1) on detail from Nanomaterials Processing and Characterization Laboratories,
Graduate Program in Physical Sciences, Department of Physics & Physical Sciences,
Marshall University, Huntington, WV USA;
(2) Faculty of Science, Silpakorn University, Nakornpathom, 73000, Thailand
Recently, various nanoscale materials with new architectures, improved functionality, and remarkable properties have been developed with several applications in environment, energy, national security, and analysis of cellular level processes. It is widely known that a perpetual increase in population and thus consumption of fossil fuels has led to increase in pollution worldwide - a leading contributor to chronic and deadly health disorders and diseases affecting millions of people each year. The effects of pollution and its impact on human health are highly observable as long-term exposure to air pollution provokes inflammation, accelerates atherosclerosis, and alters cardiac function.
The presentation outlines use of nano-enabled sensors for environment pollution monitoring. Extension of use of nanomaterials in photonics will enable applications in nano-satellites for localized pollution monitoring, plume modeling, and in-situ observation at sites of interest. One of the testing sites for monitoring air pollution over residential and industrial areas is in Bangkok, Thailand. Results of our ongoing investigation using cost-effective nano-enabled gas–sensors, Internet GIS based real time air pollution monitoring system, and numerical and air dispersion modeling employing remote sensing methodologies will be presented.
The presentation will cover an exhaustive overview of the scope of our investigation and some specific applications relating to the use of nanomaterials in environmental friendly investigations. It is expected that such emerging and potentially transformative studies will provide major contribution to improving the quality of the life of citizens worldwide.
Evaluation of In Vitro Toxicity of Fullerene nC60 Derivatives Formed in Conditions that Simulate Disinfection Processes
Alla L. Alpatova1, Pavel Babica2, Syed A. Hashsham1, Brad L. Upham2, Susan J. Masten1, Volodymyr V. Tarabara1. (1) Department of Civil and Environmental Engineering, Michigan State University, East Lansing, MI, USA; (2) Department of Pediatrics and Human Development, Michigan State University, East Lansing, MI, USA
The progress in the development of facile methods of producing water-soluble fullerene aggregates (nC60) brings about a higher likelihood of these materials’ entering natural water reservoirs and drinking water supplies. Existing literature data on the potential toxicity of fullerenes and their derivatives show that the toxicity, if observed, is a strong function of the surface chemistry of fullerenes species. Disinfection processes such as ozonation and chlorination could, under certain conditions, modify surface properties of solubilized C60 nanoparticles and alter their toxicity. The study to be presented was aimed at the assessment of the toxicity of derivatized nC60 nanoparticles formed in conditions that simulate disinfection processes in a water treatment plant
Evaluation of Nanoparticle and Matrix Characteristics
Impacting Transport in the Environment
Arianne M. Neigh, Thomas K. Darlington, Thomas K., Oanh
Nguyen, , Steven J. Oldenburg, nanoComposix, Inc., USA
Concern is mounting over the potential for nanomaterials to enter the environment and cause adverse effects to biota and human health. While in vitro and in vivo toxicity research has progressed, there is a critical gap in the scientific literature linking release and exposure potential to the current body of toxicity evaluations on nanomaterials. Few studies have evaluated a reasonable scenario for release to the ambient environment and attempted to determine how materials interact, are transported, and may change physically and chemically. Aluminum nanoparticles are being used in combination with metal oxides in propellants and have the potential to be released to the environment through aerosol deposition. Although aluminum is abundant naturally in the soil matrix, aluminum loading can lead to toxicity if it is transported to aquatic systems in soluble forms. Aluminum chemistry is complicated and the unique characteristics of aluminum at the nano-scale are not well understood. The objective of the study was to evaluate how aluminum nanoparticles changed physically and chemically in different environmentally relevant scenarios and how these changes affect transport. Aluminum nanoparticles were suspended in the different media by sonication and eluted by a forced up-flow system through the soil matrix over 17 hrs at a rate of 3 ml/hr. The type of media used to suspend the nanoparticles had a marked effect on the surface charge, stability, and aggregation state of the nanoparticles prior to introducing to the soil column. The properties of the suspension at the time of introduction and throughout the course of the experiment were important in determining transport. Additionally, the properties of the soil matrix including pore size, charge on the surface of the grains, salt content, and composition further impacted transport. Suspended aluminum nanoparticles with negatively charged surfaces had the highest rate of transport of the scenarios evaluated. Transport was also greater for matrices composed primarily of sand compared to those containing greater proportions of fine particulates. It is clear from these studies that many factors influence the transport of nanoparticles in the environment and transport cannot be reliably predicted from one factor alone, but evaluation should include many different physicochemical aspects of the nanoparticles and soil.
Fate and Transport of Titania Nanoparticles in Freshwater Mesocosms
Ann Miracle, Amoret Bunn, Jill Brandenberger, Dan Gaspar, Jeff Ward, Pacific Northwest National Laboratory, USA
Titania nanoparticles are currently associated with air, soil, and water and with numerous products directed at human use and consumption (e.g., sunscreen, cosmetics, and food coatings). The environmental fate and transport of TiO2, or any nanomaterials entering dynamic aquatic environments are largely unknown. Because the physical and chemical properties of TiO2 are variable (size, surface chemistry, and composition), the movement, bioaccumulation, and toxicity of these materials are difficult to study in a complex ecosystem. Many metal oxide materials are durable and recalcitrant, and the accumulation of TiO2 in the environment could be significant over time and cause unforeseen impacts on ecosystems. Fate and transport of TiO2 nanomaterials in a bench-scale mesocosm system was assessed through nanomaterial partitioning and complexation in water, sediment, and tissue media characterized using inductively coupled plasma mass spectrometry and scanning electron microscopy with energy dispersive X-ray spectroscopy, respectively. Research data sets like these will build the foundation for future use in fate and transport of other nanomaterials in different water systems (fresh, estuarine, and marine) and in building empirical and process models that investigate environmental fate and transport and relevant freshwater ecological impacts of nanomaterials.
Fate of Engineered Nanoparticles during Biological
Wastewater Treatment
Ayla
Kiser, Paul
Westerhoff, Bruce Rittmann, Department of Civil and Environmental Engineering, Arizona State University; USA
Engineered nanoparticles (eNPs) are becoming prevalent in a gamut of consumer products, including cosmetics, clothing, paints, and food. These nanomaterials will be released into domestic sewage through people’s common daily activities, such as the flushing of urine and feces or the rinsing of cosmetics or sunscreens off of the skin. As society’s use of nanomaterials increases, wastewater treatment plants (WWTPs) will serve as important collection points of eNPs and, consequently, provide pathways of eNPs into the natural environment. Thus, investigation of the passage of eNPs through WWTPs is critical for understanding and predicting the environmental fate of eNPs and the degree of exposure to humans and various ecosystems, yet little research currently exists in this area.
WWTPs consist of engineered biological reactors in which bacteria are continuously grown and used to remove carbon and nutrients from wastewater. Our research with engineered nano-scale titanium dioxide, fullerenes, and silver shows that these nanoparticles have a high tendency for removal from wastewater by bacterial biomass. Thus, a major pathway of eNPs into the environment is likely to be from wastewater biosolids, which are typically applied to agricultural land, landfilled, or incinerated. Possible mechanisms of nanoparticle removal by biomass are investigated: sorption to cell surfaces, enmeshment in extracellular polymeric substances (EPS), or uptake into cells. We demonstrate that EPS, which are produced by bacteria and constitute a significant fraction of biomass, play an important role in facilitating the removal of eNPs during biological wastewater treatment. The methods and conclusions from this research provide foundational knowledge of nanoparticle interaction with bacterial biomass, as well as evidence of the environmental fate of eNPs.
Fate of Quantum Dot
Nanomaterials in Unsaturated and Saturated Porous Media
Christophe Darnault1,
Solidea Bonina1, Burcu Uyusur1 and Preston Snee2.
(1) Department of Civil and Materials Engineering, University of Illinois at
Chicago, USA; (2) Department of Chemistry, University of Illinois at Chicago,
USA
Nanomaterials are at the leading edge of the rapidly growing field of nanotechnology. While the potential benefits of nanotechnology are "almost limitless," little is known about its possible harmful effects, and the benefits will be realized only if adverse consequences are examined and managed. Therefore, research on the fate and transport of nanomaterials is a priority research area as once nanomaterials are released into the environment, their transport is the critical parameter in assessing their exposure and impact on the public health and the ecosystem. As semiconductors, quantum dots are key enablers in nanosciences, engineering and technology. The toxicity of quantum dots depends on their physicochemical properties and the environmental conditions. This paper will present our research on the visualization and transport phenomena of quantum dot nanomaterials in porous media, including the development of non-intrusive, high spatial and temporal resolution method to visualize transport and measure quantum dot nanomaterials concentration in porous media and on the mechanisms that control the transport, or lack of mobility, of engineered nanomaterials - quantum dots - in subsurface complex and heterogeneous environment. The visualization technique used to explore the transport of quantum dot nanomaterials is a toolbox that allows characterization of a wide range of flow and transport phenomena due to mesoscale heterogeneities. The characterization of these flow and transport phenomena includes the visualization and/or quantification of flow, fluid content and nanoparticle concentrations. The visualization technique selected to investigate transport of quantum dot nanomaterials in two-dimensional variably saturated porous media is a non-intrusive method based on transmitted fluorescence resulting from the quantum dots optical properties. The visualization procedure consists in exciting fluorescent quantum dots in porous media by using light emitted devices as a light source on one side of the chamber and detecting the light emitted from quantum dots and transmitted through the porous media through a camera located on the opposite side. The visualization, calibration and image analysis are performed using an imaging-software. Experiments investigating quantum dot nanomaterials transport in unsaturated zone demonstrates the effects of preferential flow on the transport of quantum dot nanomaterials through the vadose zone; while investigation of quantum dot nanomaterials transport in saturated zone examines the particle filtration theory and collector efficiency for the case of quantum dot nanomaterials subjected to groundwater flow conditions.