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Environmental Impact of Engineered Nanomaterials

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Environmental Impact of Engineered
Nanomaterials and Management
of Nano-waste in
Industrial Wastewater
Manal. G. Eloffy ...

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Outlines
Concept-Definitions
of ENMs
Applications
of ENMs
Advantages
of ENMs
Disadvantages
of ENMs
Impact of
Nanomaterials...

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The Concept
In 1959, physicist and Nobel prize laureate Richard Feynman presents "There's
Plenty of Room at the Bottom" at...

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Environmental Impact of Engineered Nanomaterials

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Environmental Impact of Engineered Nanomaterials and Management of Nano-waste in Industrial Wastewater

Environmental Impact of Engineered Nanomaterials and Management of Nano-waste in Industrial Wastewater

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Environmental Impact of Engineered Nanomaterials

  1. 1. * Environmental Impact of Engineered Nanomaterials and Management of Nano-waste in Industrial Wastewater Manal. G. Eloffy 2017 *National Institute of Oceanography and Fisheries *Chemical Engineering Department, Faculty of Engineering, Alexandria University, Egypt
  2. 2. Outlines Concept-Definitions of ENMs Applications of ENMs Advantages of ENMs Disadvantages of ENMs Impact of Nanomaterials Nano-waste Management (Case study)
  3. 3. The Concept In 1959, physicist and Nobel prize laureate Richard Feynman presents "There's Plenty of Room at the Bottom" at a meeting of the American Physical Society and introduces the concept of nanotechnology – without naming it as such He described how the laws of physics do not limit our ability to manipulate single atoms and molecules. Feynman explored the possibility of manipulating the materials at a scale of individual atoms and molecules, imagining the whole of the encyclopedia Britannica written on the head of the pin.
  4. 4. The Growth of Nanomaterials
  5. 5. Nano-scale The prefix nano means a factor of: one billionth (10-9) and can be applied, e.g., • Time (nanosecond), • Volume (nanoliter), • Weight (nanogram), • Length (nanometer). Nanomaterials are manufactured materials with a structure between approximately 1 nm and 100 nm.
  6. 6. Number of products, According to region Number of products associated with specific materials Statistics about Nanomaterials
  7. 7. Classes of Nano-materials • Engineered nanomaterials: the phrase ‘engineered nanomaterials’ is used to describe inorganic materials of high uniformity, with at least one critical dimension below 100 nm, specifically engineered for applications. • Incidental nanomaterials: Materials with a structure between approximately 1 nm and 100 nm that are produced as a by-product of a process. For instance, welding fume and diesel emission particulates would be considered incidental nanomaterials. • Natural nanomaterials: Materials with a structure between approximately 1 nm and 100 nm that are a result of natural processes. Some particles arising from volcanic emissions, sea spray, and atmospheric gas-to-particle conversion would be considered natural nanomaterials.
  8. 8. SWOT Analysis “Strengths” : Which nanomaterials are presently industrially used in the corresponding sector? What are their technological and socio-economic advantages. “Weaknesses” What are the actual technological and socio-economic barriers to be overcome concerning products and applications in the corresponding sector? Opportunities” How can R&D opportunities in nanomaterials (new development of nanomaterials, scientific breakthroughs) solve the existing problems and improve the existing weaknesses of products? “Threats” What are the threats/risks linked with the new opportunities; technological, market and socio-economic risks? Actual industrial state Trends and vision in the sector Strengths S Weaknesses W Threats T Opportunities O
  9. 9. R&D producing numerous engineered NPs At least 1 dimension ≤100nm but very different physical characteristics • Fullerenes: carbon-only molecules (hollow sphere, ellipsoid, tube, or plane) • Carbon nanotubes (CNT): cylindrical (single or multi-walled, capped or uncapped) • Metals & metal oxides: ultrafine powders (e.g. Ag, Au, ZnO, TiO2, CeO) • Quantum Dots (QD): semi-conducting crystal core (e.g. CdSe, CdS core, ZnS coat) • Nanowires: large aspect ratio • Nano-crystals: crystalline nanomaterial • Others: dendrimers, graphene sheets, nano-screen arrays; hybrids. Types of Nanomaterials Fullerenes Carbon nanotubes (CNT): Dendrimers Graphene sheets
  10. 10. Top-down Manufacturing :- It involves the construction of parts through methods such as cutting, carving and molding. Using these methods, we have been able to fabricate a remarkable variety of machinery and electronics devices. Bottom-up manufacturing :- On the other hand, would provide components made of single molecules, which are held together by covalent forces that are far stronger than the forces that hold together macro-scale components. Further more, the amount of information that could be stored in devices build from the bottom up would be enormous Synthesis and Processing of Nano-materials Getting merely a small size is not the only requirement. It should have • Identical size of all particles (also called mono sized or with uniform size distribution. • Identical shape or morphology. • Identical chemical composition and crystal structure • Individually dispersed or mono dispersed i.e., no agglomeration.
  11. 11. Advantages of Nanomaterials lighter materials move to less energy consumption reduction of waste providing faster, smaller and enhanced hand held devices CO2 reduction , reduction in the use of pesticides and improved water management self-cleaning, anti-bacteria and antifouling properties better patient care and understanding of biological processes
  12. 12. Commercial Applications of Nanomaterials Computing and Data Storage Agriculture: fertilizers& pesticides Industrial sector and New Products Health and Medicine Energy Transportation National Security Space Exploration pollution prevention water treatment and Desalination
  13. 13. Health, 20 Environment, 16 Medicine, 13 Agriculture / Veterinary, 2 Food, 49 distribution % Health Environment Medicine Agriculture / Veterinary Food Distribution of nanomaterials applications
  14. 14. pollution prevention • Pollution Detection and Sensing: Various nanostructured materials have been explored for their use in sensors for the detection of different compounds. An example is silver nanoparticle array membranes that can be used as flow-through Raman scattering sensors for water quality monitoring. The particular properties of carbon nanotubes (CNTs) make them very attractive for the fabrication of nano- scale chemical sensors and especially for electrochemical sensors • More Efficient Resource and Energy Consumption: Pollution prevention by nanomaterials refers on the one hand to a reduction in the use of raw materials, water or other resources and the elimination or reduction of waste and on the other hand to more efficient use of energy or involvement in energy production
  15. 15. Wastewater Treatment • Adsorption of Pollutants • Magnetic Nanoparticles • Nano-filtration& Nano - fiber • Degradation of Pollutants (photo-catalysis) • Zero-valent Iron Nanoparticles
  16. 16. Adsorption of Pollutants Magnetic Nanoparticles Degradation of Pollutants (photo-catalysis) Nano-filtration& Nano - fiber
  17. 17. Applications of Nanomaterials in Water Desalination • Nanomaterials have been examined in many applications to enhance the mechanical, thermal, and chemical stabilities of membranes in severe conditions • Nano-composite membranes showed good antibacterial ability (Silver Nanoparticles)
  18. 18. Difficulty in synthesis - It is extremely hard to retain the size of nanoparticles once they are synthesized in a solution. Biologically harmful – Nano-materials are usually considered harmful as they become transparent to the cell-dermis. Recycling and disposal - There are no hard-and-fast safe disposal policies evolved for nano-materials. Instability of the particles . Fine metal particles act as strong explosives owing to their high surface area coming in direct contact with oxygen. Impurity - Because nanoparticles are highly reactive, they inherently interact with impurities. Disadvantages of Nanomaterials
  19. 19. • All substances, from arsenic to table salt are toxic to cells, animals or people at some exposure level. • The toxicity and exposure metrics are traditionally driven by mass of the particle composition, but in the case of nanoparticles, the metrics are far more complex. • The particle number, particle size, surface area, shape, crystal structure, surface charge • It is essential to characterize the expected concentrations of engineered nanoparticles that may be present in the air, water and soil. • Who is exposed to nanomaterials • How may people be exposed to engineered • nanoparticles and in what quantities? Nano-toxicology Issues
  20. 20. Environmental Toxicity • Environmental risks associated with nanomaterials are not well characterized. • Nanoparticle pollution, by deposition of nanoparticle in groundwater & soil. • Process that control transport & removal of nanoparticles in water and waste water are yet to be investigated. • Studies on the effect of nanoparticles on plants and microbes are also rare. • To date, few studies have investigated the toxicological and environmental effects of direct and indirect exposure to nanomaterials and no clear guidelines exist to quantify these effects.
  21. 21. Environmental impact
  22. 22. Polycyclic Aromatic Hydrocarbons (PAHs)Chlorinated Dioxins and Furans (PCDFs) • can induce cancer, • can cause mutations in genetic material, • and can interfere with the proper functioning of hormones. • In addition, some of these compounds can remain in the environment for a long time and be transported long distances from where they were originally released. Disposal of Nano-waste through incineration produces hazardous pollutants. The small size of nanomaterials and their large surface area may enhance the formation of hazardous pollutants. Air pollution control equipment Emissions of Pollutants from Nano-waste
  23. 23. Absorption & Translocation Potential biological effects Bioaccumulation ▪ Allergy ▪ Fibrosis ▪ Deposition in different organs(lead to organ failure) ▪ Inflammation ▪ Cytotoxicity ▪ Tissue damage ▪ ROS generation ▪ DNA damage ▪ By 2020, there will be 6 million workers in nano-science and manufacturing worldwide Nanomaterials are more easily taken up by the human body and can cross biological membranes, cells, tissues and organs more efficiently than larger particles. Nanomaterials - human health risk
  24. 24. The main parameters of interest with respect to Nano- materials safety are: Physical properties •Size, shape, specific surface, aspect ratio •Agglomeration/aggregation state •Size distribution •Surface morphology/topography •Structure, including crystallinity and defect structure •Solubility
  25. 25. Chemical Properties • Structural formula/molecular structure • Composition of nanomaterials (including degree of purity, known impurities or additives) • Phase identity • Surface chemistry (composition, charge, tension, reactive sites, physical structure, photocatalytic properties, zeta potential) • Hydrophilicity/hydrophobicity
  26. 26. Modification of Nanomaterials t Reduce Hazard Potential Surface chemistry effects can influence toxicity: Polarity (hydrophilicity) : ▪ e.g. progressive C60 derivatisation increases polarity and decreases cytotoxicity Surface charge: ▪ +ve charged NP preferentially taken up by living cells, due to -ve charge on cell membranes, ▪ toxicity of quantum dots (QD) is progressively reduced by polymer coatings of increasing thickness and different surface charge
  27. 27. Treatment of Nanomaterials in the Aquatic Mediums by CFS/Ultrafiltration Membrane System
  28. 28. Schematic Diagram of Pre-treatment Coagulation/Flocculation System
  29. 29. Schematic Diagram of the Ultrafiltration Experimental Set-up.
  30. 30. Zeta potential ``````` ``````` ``````` ``````` ``````` ``````` ````
  31. 31. Stability Characteristics Avg. Zeta Potential (mV) Maximum agglomeration and precipitation 0 to +3 Range of strong agglomeration and precipitation +5 to -5 Threshold of agglomeration -10 to -15 Threshold of delicate dispersion -16 to -30 Moderate stability -31 to -40 Fairly good stability -41 to -60 Very good stability -61 to -80 Extremely good stability -81 to -100 Stability of Nanomaterials Related to Zeta Potential
  32. 32. Transmission Electron Microscope (TEM), Image for Silica NPs before and after treatment dispersed Silica nanoparticles coagulated Silica nanoparticles
  33. 33. Efficiency of Nanomaterial removal
  34. 34. (Material Safety Data Sheet) MSDS Information sharing to keep a safe (Personal Protective Equipment) PPE Safety Engineering Equipment Disposal of nanomaterials ( nano-waste ) Recommendations
  35. 35. As Nanomaterials are Used in More and More Consumer Products, Further Studies on their Environmental and Health Impacts are Wanted. KEEP IN MIND…
  36. 36. THANK YOU

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