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

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. Outlines
Concept-Definitions
of ENMs
Applications
of ENMs
Advantages
of ENMs
Disadvantages
of ENMs
Impact of
Nanomaterials
Nano-waste
Management
(Case study)

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. The Growth of Nanomaterials

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. Number of products, According to region Number of products associated with specific materials
Statistics about Nanomaterials

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. 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. 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. 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. 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. 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. Health, 20
Environment, 16
Medicine, 13
Agriculture / Veterinary, 2
Food, 49
distribution %
Health Environment Medicine Agriculture / Veterinary Food
Distribution of nanomaterials applications

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. Wastewater Treatment
• Adsorption of Pollutants
• Magnetic Nanoparticles
• Nano-filtration& Nano - fiber
• Degradation of Pollutants (photo-catalysis)
• Zero-valent Iron Nanoparticles

16. Adsorption of Pollutants Magnetic Nanoparticles
Degradation of Pollutants (photo-catalysis) Nano-filtration& Nano - fiber

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. 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. • 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. 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. Environmental impact

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. 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. 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. 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. 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. Treatment of
Nanomaterials in the
Aquatic Mediums by
CFS/Ultrafiltration
Membrane System

28. Schematic Diagram of Pre-treatment Coagulation/Flocculation System

29. Schematic Diagram of the Ultrafiltration Experimental Set-up.

30. Zeta potential
```````
```````
```````
```````
```````
```````
````

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. Transmission Electron Microscope (TEM), Image for Silica NPs before and after treatment
dispersed Silica
nanoparticles
coagulated Silica
nanoparticles

33. Efficiency of Nanomaterial removal

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. As Nanomaterials are Used in More and More Consumer
Products, Further Studies on their Environmental and Health
Impacts are Wanted.
KEEP IN MIND…

36. THANK YOU