Nanotechnology is set to play a vital role in cleaning pollution from the environment to establish a sustainable future for the planet.
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Protection of the environment is one of the critical challenges faced by humanity. Over the years, anthropogenic activities have devastated our surroundings by creating and discarding plastics, contributed to climate change by mining and burning fossil fuels, and contributed to water and air pollution.
Why Use Nanotechnology to Protect the Environment?
Nanotechnology is based on nanomaterials, nano-sized materials that exhibit unexpected properties compared to their bulk counterparts; their high surface-area-to-volume ratio imparts unique physiochemical properties, including versatile functionalities and enhanced reactivity or selectivity.
From saving raw materials, energy and water, to decreasing greenhouse gases and dangerous waste, nanotechnology has unique attributes that can be utilized in various applications to protect the environment against pollution.
Saving the Seas From Pollution With Nanotechnology
Oil spills are a major source of pollution for any aquatic environment, including oceans, rivers. They can also be devastating for the wildlife that resides there. Conventional methods of clearing spillages from the environment are inadequate. Although still in their infancy, nanotechnology solutions show great promise as an alternative means of tackling this type of pollution.
Following the Deepwater Horizon disaster in 2010, researchers from the State University of New York (SUNY) Stony Brook developed a nanogrid of photocatalytic copper tungsten oxide nanoparticles. When activated by sunlight, these nanoparticles break oil down into biodegradable compounds, thus clearing the pollution via a nanotechnology solution powered by sunlight.
“Ours is a unique technology. When you shine light on these grids, they begin to work and can be used over and over again,” said Pelagia-Irene Gouma, professor in the Department of Materials Science and Engineering.
While methods to clean up the pollution created by oil spills have advanced, they continue to be a blight on the environment. In 2020, 21,000 tons of fuel spilled into arctic waters after a fuel reservoir collapsed. It is estimated that the spill will take years to clean up.
Further innovations in nanotechnology will be important in ensuring the quality of the world’s oceanic environment is not destroyed further. Recently, robots equipped with nanowire mesh were deployed to help clean up a devastating oil spill in Mauritius.
Scientists believe this innovative method is capable of cleaning up an oil spill the size of the Gulf of Mexico in just one month with 5,000 nanotechnology-enabled robots.
Nanotechnology and Water Cleanliness
Pollution enters the environment via many sources, mainly through human activities such as burning fossil fuels, agriculture and industry emissions, and vehicle exhaust fumes. This pollution finds its way into water sources, posing a significant risk to the health of the environment and the wildlife that inhabit it.
Nanotechnology-based solutions can address water pollution and contribute to the long-term quality, availability, and viability of water in several ways:
Nanotechnology for Water Treatment and Remediation
Nanotechnology could yield a new generation of nanomembranes for separation to enable greater water purification and desalinization and better means of removing, reducing, or neutralizing water contaminants that contribute to water pollution. The latter might include zeolites, carbon nanotubes, self-assembled monolayer on mesoporous supports (SAMMS), biopolymers, and single-enzyme nanoparticles, to name a few.
Sensing and Detection to Protect the Environment
New and enhanced sensors capable of detecting chemical and biological contamination at low concentrations are achievable with nanotechnology. Nanomaterials also enable photoelectrochemical analysis, integrating light response and chemical sensing for biological and chemical monitoring and negating the need for expensive and sophisticated instruments and operations.
New nanotechnology sensors can protect the aquatic environment by detecting pollution even at very low levels. These sensors also make continuous monitoring possible so that pollution levels can be understood in the context of external factors, helping to attribute the causes of water pollution, and highlighting how to prevent it.
Pollution Prevention With Nanotechnology
Pollution prevention includes tackling traditional pollutants as well as waterborne infectious diseases. For example, nanotechnology could provide alternative chlorine-free biocides in the form of silver and titanium dioxide catalysts for photocatalytic disinfection.
Practical water-cleaning applications include utilizing iron nanoparticles to remove organic solvents in groundwater. The nanoparticles disperse through the water and decompose solvents without the need to pump water out of the ground, making the method more effective and less expensive.
Nanotechnology-based solutions can also remove radioactive waste. Titanate nanofibers are good absorbents to remove radioactive ions such as cesium and iodine from water.
Cleansing the Air with Nanotechnology
Carbon dioxide (CO2) is perhaps the biggest threat to the environment. The industrial revolution, accompanied by the increasing necessity to burn fossil fuels, has resulted in vast amounts of this greenhouse gas polluting the atmosphere and driving climate change. Consequently, the planet is warming, the polar ice caps are melting, and many low-lying lands are at risk of disappearing altogether.
Not only is air pollution heating the Earth, but it is also a significant contributor to human illness. A growing body of evidence exists that links air pollution to serious health conditions such as cancer. This impact on health makes cleaning air pollution even more urgent.
Utilizing renewable energies is already reducing the amount of CO2 released into the environment. However, the burning of fossil fuels continues, driving the need to capture and store CO2 released into the atmosphere to protect the environment.
Current methods to separate CO2 from waste gases are expensive, utilize chemicals, and are not competitive enough for large-scale applications. Nanotechnology offers a solution: membranes constructed from nanomaterials could work similarly at a fraction of the cost and without additional compounds.
Researchers in Germany have devised a nanotechnology solution. Here, the team fabricated an ultra-thin nanoscale polymer film that filters out CO2 with unmatched results. Its high permeance is attributable to the CO2-philic material, which is only a few tens of nanometers thick. Researchers say the material could be used for CO2 capture from flue gases in coal-fired power plants.
The most recent research into carbon capture technology involves the development of novel nanomaterials known as metal-organic-frameworks (MOFs). Research shows that MOFs are strong candidates for CO2 absorption. In particular, a subgroup of MOFs, zeolite imidazolate frameworks (ZIFs), may be fundamental to the future of cleaning pollution from the air.
Finally, volatile organic compounds (VOCs) also represent a hazard to air quality, contributing to smog and high ozone levels. Again, nanotechnology offers a solution. Japanese researchers discovered a way to remove VOCs – as well as sulfur and nitrogen oxides – from the air at ambient temperatures. They utilized porous manganese oxide with gold nanoparticles grown into it as a catalyst to decompose and remove the offending compounds.
Creating a Delicate Balance Between Nanotechnology and the Environment
Nanotechnology offers an enormous opportunity to clean and protect the environment; however, a balance must be reached that considers the needs of the environment and the activity, selectivity, and stability of the nanotechnology chosen.
Many of the desirable qualities of nanotechnology – such as its high performance – result from its high reactivity, caused by its delicate surface and microstructure. As such, we must be careful to avoid damage and degradation of nanotechnology to ensure we do not initiate a new source of pollution.
References and Further Reading
Sun, H. (2019) Grand Challenges in Environmental Nanotechnology, Frontiers in Nanotechnology [online] https://doi.org/10.3389/fnano.2019.00002
Cimons, M. (2013) Nanogrid, activated by sunlight, breaks down pollutants in water, leaving biodegradable compounds, National Science Foundation [online] https://www.nsf.gov/discoveries/disc_summ.jsp?cntn_id=129566
Berger, M. (2010) Carbon dioxide capture with nanometric thin-film membranes, Nanowerk [online] https://www.nanowerk.com/spotlight/spotid=18139.php
Yave, W. et al. (2010) Nanometric thin film membranes manufactured on square meter scale: ultra-thin films for CO2 capture, Nanotechnology [online] https://iopscience.iop.org/article/10.1088/0957-4484/21/39/395301
Nanowerk, Nanotechnology and the environment, Nanowerk [online] https://www.nanowerk.com/nanotechnology-and-the-environment.php
UnderstandingNano, Environmental Nanotechnology, UnderstandingNano [online] https://www.understandingnano.com/environmental-nanotechnology.html
Science Daily (2007) New Material Removes Pollutants From Air, Science Daily [online] https://www.sciencedaily.com/releases/2007/03/070330185114.htm
This article was updated August 2023.