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Seminar Presentation OnThe Application Of
Nanotechnology in Microbial Pollution Control
ByEze Chinwe Catherine
Department of Environmental Technology
School of Environmental Sciences
Federal University of Technology, Owerri
Introduction and Definition of Nanotechnology
The study of manipulating matter at atomic and molecular scale, a creation of functional materials, devices and systems through control of matter on nanometer scale
National Nanotechnology Initiative defined it as as “the understanding and control of matter at the nanoscale, at dimensions between approximately 1 and 100 nanometers, where unique phenomena enable novel applications.”
Conceived in 1959 by Nobel Laureate physicist Richard P. Feynman in an inspiring lecture titled ‘‘There's Plenty of Room at the Bottom" at an American Physical Society meeting.
First coined in 1974 by Japanese scientist Norio Taniguchi in a paper titled “On the Basic Concept of Nanotechnology’’. He defined it as consisting of the processing of, separation, consolidation and deformation of materials by atoms or molecules.
Interest in nanotechnology boomed after the discovery of buckminsterfullerene in 1985 by Noble Laureates Richard Smalley, Robert Curl, and Harry Kroto.
Popularised by American engineer K. Eric Drexler in the book Engines of Creation: The Coming Era of Nanotechnology.”(1986). Father of Nanotechnology in his Biology studies
Fundamentals and Approaches to
Nanotechnology The fundamentals of nanotechnology lie in the fact that properties of substances dramatically change when their size is reduced to the nanometer
thermal and electrical conductivity, optical absorption emission spectra, and electronic properties - develop selective
sensors for water quality monitoring,toxic or harzadous environment mechanical strength, and viscosity , ,short intraparticle diffusion distance highly specific surface area with associated sorption sites -adsorption, fast
dissolution, high reactivity(polishing step to remove organic and inorganic contaminants in water and wastewater treatment).
photosensitivity, catalytic and anti - microbial activity - destroy recalcitrant pollutants,
and magnetic properties for, particle separation and reuse, tunable pore size and surface chemistry are size dependent
The two fundamentally different approaches to technology are graphically termed 'top down' and 'bottom up'.
The small size of nanomaterials gives them specific or enhanced physico-chemical properties, compared with the same materials at the macroscale,
ENMs can be divided into four different classes:• Carbon-based materials (e.g. fullerenes), Metal-based materials (e.g. TiO2 NPs),• Dendrimers (e.g. nano-sized polymers), Composites (i.e. mixtures of NPs).layers, multi-layers, thin films, platelets and surface coatings. They have been developed and used for decades, particularly in the electronics industry.
One-dimensional nanomaterials
nanowires, nanofibers made from a variety of elements other than carbon, nanotubes and, a subset of this group, carbon nanotubes. A fullerene : molecule composed entirely of carbon, in the form of a hollow sphere, ellipsoid, or tube. Spherical fullerenes =buckyballs. Cylindrical ones =carbon nanotubes or buckytubes.
Two-dimensional nanomaterialsfullerenes
precipitates, colloids and quantum dots (tiny particles of semiconductor materials), Nanocrystalline materials
Three-dimensional-nanomaterials nanoparticles: metallic, semiconductors or oxide particles having dimensions between 1 to100nm
Nanomaterials’ Characteristics
Challenges in Conventional water
treatment techniques - Space requirements - Monitoring difficulties - Extended treatment time - very costly and labour- intensive Aging water treatment and distribution systems in many cities
cannot ensure reliable disinfection some systems serve as incidental sources of microbial diseases produce carcinogenic disinfection byproducts (DBPs), such as
trihalomethanes, haloamides, halonitriles, and bromate. microbial infiltration, biofilm formation, and biofouling, corrosion
Some microbial processes of concern to the O&Gindustry.
• sulphate-reducing bacteria in well bores and O&G fields sour hydrocarbon reservoirs due to the generation of hydrogen sulfide (H2S).biocorrosion
• These sulfides also can precipitate as biogenic minerals in pipelines and drilling fluids leading to flow obstruction, interruptions in extraction processes, and higher water requirements for O&G extraction.
• Conventional biocides -low specificity to sulfate-reducing bacteria-high dosage that leads to undesirable reactions-leave significant residuals -environmental risks
Biofouling Control
Applications of Carbon nanotubes (CNTs)
a special class of fullerenes with antimicrobial properties
physical interaction in which CNTs pierce cells, thus inhibit microbial attachment and biofilm formation on surfaces, inactivate viruses
high mechanical strength, heat resistance, and easy cleaning.
Applications of nanoparticles Silver ions: generated from the silver surface bind to the reactive group in the
target cell or organism, resulting in their precipitation and inactivation, kill both gram-positive and gram-negative pathogenic bacteria. especially, Staphylococcus aureus, E.coli, Klebsiella pneumoniae and Pseudomonas .
Combined with TiO2 nanoparticles, can be used to enhance antibacterial, deodorizing, and photocatalytic effects of TiO2 (Three-bond chemicals) in the presence of light and humidity.
Gold Magnetic nanoparticles are being developed to adsorb metals and organic contaminants.
Cerium oxide (CeO2) can be used as a diesel fuel combustion catalyst, which reduces fuel consumption, carbon monoxide (CO) emissions, and other harmful exhaust emissions
Nanoparticles can be mixed with water to form a slurry that can be injected using pressure or gravity into a contaminated plume . Once injected, the particles remain in suspension, forming a treatment zone.
A. Nanorust cleans arsenic from drinking waterB. Nanoscale zero-valent iron encapsulated in an emulsion droplet. These nanoparticles have been used for remdiation of sites contaminated with variuos organic pollutants c. Nanotechnology-enabled integrated urban water management
Application in bioremediation bioremediation makes use of enzymesspecificity and targeted effectiveness than synthetic catalysts. lack of stability and relatively short life inhibit their ability to provide cost effective options. Methods such as enzyme immobilization, enzyme modification,
and genetic modification, to improve the stability and subsequent persistence of enzymes.
Nanotechnology: a new method of enzyme stabilization single enzyme nanoparticles (SENs) armored enzymes surrounded by a protective cage a few nanometers thick . The “cage” is actually a silicate shell, linked with the surface of the enzyme. While it covers most of the enzyme, the active site remains chemically accessible, maintaining the functionality of the enzyme
used to remediate recalcitrant compounds, withstand more extreme conditions, such as high/low pH, high contaminant concentration, high salinity, and high/low temperature. Enzymes also do not require nutrients and biomass
acclimation. Metabolic intermediates and by products, as well as mass transfer limitations due to cellular transport, are avoided as well.
Generally, it is a much easier process to control than whole cell degradation
Other uses include: Nanoscale additives to or surface treatments of fabrics help them resist wrinkling, staining, and bacterial growth water-repellent, antireflective, self-cleaning, Nanoscale thin films on
eyeglasses, computer and camera displays, windows, Nano-engineered materials make superior household products such as
degreasers and stain removers; environmental sensors, alert systems, air purifiers and filters
nanofabric "paper towel," woven from tiny wires of potassium manganese oxide, that can absorb 20 times its weight in oil for clean-up applications.
Emerging Nanotechnology-Enabled Disinfection and Microbial Control
Applications Unlike conventional chemical disinfectants, antimicrobial nanomaterials are generally weaker oxidants and do not produce harmful DBPs(disinfection byproducts)
Naturally occurring antibacterial macromolecules, such as chitosan (obtained from chitin in arthropod shells), could also be useful in water disinfection.
Chitosan can be made into nanoparticles with broad disinfection capabilities. The antimicrobial mechanisms of (positively-charged) chitosan likely involve its interaction with negatively-charged cell membranes.
applications in air, water pollution treatment Antimicrobial nanomaterials are envisaged to find their
applications in three critical challenges in water/wastewater systems: disinfection, membrane biofouling control, and biofilm control on other relevant surfaces.
Nano-catalysts with increased surface area are used for gaseous reactions. Catalysts work by speeding up chemical reactions that transform harmful vapors from cars and industrial plants into harmless gases
a nanofiber catalyst made of manganese oxide that removes volatile organic compounds from industrial smokestacks.
Another approach uses nanostructured membranes that have pores small enough to separate methane or carbon dioxide from exhaust
Nanobiosensors Sensors are sophisticated instruments which respond to physico-
chemical and biological aspects and transfer that response into a signal or output that can be used by humans. They allow the detection of contaminants such as microbes, pests, nutrient content
One of the major roles of nanotechnology enabled devices is to increase the use of autonomous sensors linked to a global positioning system (GPS) system for real time monitoring. Nanoparticles or nano-surfaces can be engineered to trigger an electrical or chemical signal in the presence of a contaminant such as bacterium.
Risks for the future
Environmental Risks Biological damage to date, adverse effects on populations or communities of
organisms in situ have not been investigated benefit discovered under laboratory conditions may not be
realised on a commercial scale The issue of bioaccumulation and entry of nanoparticles
and tubes into the food web has yet to be seriously addressed.
Potential Human Health Concerns Dermal absorption problems: (so small they may pass
through cell membranes) Inhalation (go to the deep lung and may translocate to the
brain i.e, could cross the blood brain barrier)
Socio Economic risks
Loss of jobs (manufacturing, farming, etc)
Oil Becomes worthless Diamonds become worthless Atomic weapons more accessible
and destructive
Conclusion Environmental nanotechnology would be
the new innovation to remediate and treat the contaminants to acceptable levels, for pollution prevention, detection, monitoring and remediation of pollutants.
In order to apply nanotechnology safely, legislation and regulation should be effective worldwide.
Thanks…!!!!
Presentation by Eze Chinwe Catherine
+234 8033409778