This article was updated on the 15th May, 2023.
The world is facing significant environmental challenges, such as improving the quality of air, soil, and water. Here, AZoNano discusses the environmental impact of nanotechnology.
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To protect the environment, industry is currently focusing on implementing methods that can detect pollutants (from chemical spills, fertilizer and pesticide run-off), improve industrial and mining sites, treat contaminants and protect public health.
Nanomaterials present an opportunity to enhance these efforts. In recent years, scientists have developed nanomaterials in applications that can assist with waste management, cleaning the environment and providing efficient, clean energy solutions, such as nanomaterial-based solar cells. In addition, nanomaterials are being increasingly leveraged in consumer products to improve their quality and performance.
As a result, we are being exposed to nanomaterials more frequently. Therefore, it is important to consider the impact of this exposure. While nanomaterials have been proven to be useful in many applications that help address environmental pollution, other evidence suggests that there may be negative impacts, such as health problems, relating to exposure to nanomaterials.
Positive Impacts: Reducing Pollution
There are many positive impacts of implementing nanotechnology in environmental applications. First, nanotechnology is being used to help improve water quality by removing contaminants from water supplies.
Some nanoparticles that can be used for remediation of water are carbon nanotubes (CNTs), zeolites, nanoparticles of zero valent iron (ZVI), silver nanoparticles, etc. Other nanomaterials like zinc oxide (ZnO), titanium dioxide (TiO2), tungsten oxide, serve as photocatalyst.
These photocatalysts can oxidize organic pollutants into harmless materials. TiO2 is the most preferred material as it has high photostability, high photoconductivity, is easily available, inexpensive and non-toxic. Silver nanoparticles have high toxicity to microorganisms such as bacteria, viruses, and fungi and have an antimicrobial effect. Also, many polymeric nanoparticles are currently being used for wastewater treatment to produce additional sources of drinking water.
Another technology,known as nanofiltration, can be used in water treatment in homes, offices, and industries. Molybdenum disulphide (MoS2) nonporous membrane is used for energy-efficient desalination of water, which filters five times more than the conventional ones.
To clean oil spills in the water bodies, a nanofabric paper towel has been developed, which is woven from tiny wires of potassium manganese oxide that can absorb oil 20 times its weight. Thus, nanotechnology provides a solution to clean contaminated water and prevent new pollution.
Another nanotechnology used in large-scale oil spill cleanup and wastewater management is nano-scale zero valent iron technology (NZVI). In simple terms, it uses activated carbon to trap and remove pollution from the water. This technology has recently been leveraged in filters for water bottles and pitchers to remove contaminants from tap water.
Nanotechnology is also used to protect the environment by cleaning up outdoor air pollution. It allows toxic gases to be removed from the air so that people can be protected from breathing in harmful contaminants. Nanotechnology has been utilized to detect pollutants at the molecular level using precise sensors.
A sensor called a nanocontact sensor has been developed, which can detect heavy metal ions and radioactive elements. These sensors have a small size, are inexpensive and are easy to use on-site. Currently, single-walled nanotubes (SWNTs) are being used to detect NO2 and NH3 gases.
Also, SWNTs sensors can accomplish high sensing activity at room temperature compared to conventional sensors, which work at 200 to 600◦C. Cantilever sensors have been developed to sense VOCs, heavy metals and pesticides. A mixture of CNTs with gold particles helps adsorb toxic gases like NOx, SO2 and CO2. Another porous nanomaterial manganese oxide has better adsorption of toxic gases due to its large surface area.
Therefore, by detecting pollutants with specific sensors, we can help protect the sustainability of human health and the environment. Thus, nanotechnology provides us with a new approach to cutting down waste production, reducing the emission of greenhouse gases and discharge of hazardous chemicals in water bodies.
Negative Impacts: Environmental Exposure
Ironically, while nanomaterials have been developed in many applications that clean up pollution and contaminants, studies have also shown that exposure to some nanomaterials can have a negative impact on the environment.
Recent research has shown that nanoparticles that have been released into the environment in the form of waste can have a significant negative health impact on marine organisms. Studies have found increased cytotoxicity and oxidative stress in marine microalgae and copepod organisms as a result of this type of nanoparticle exposure.
Other studies have revealed that the accumulation of nanoparticles in the soil, particularly copper oxide, lanthanum oxide, cerium oxide, and nickel oxide, can reduce the rate of photosynthesis and transpiration of plants growing in the soil.
More research is needed to fully understand the impact of nanoparticle pollution on the environment. However, it is clear that caution must be taken with the use of nanoparticles and nanotechnology to prevent the unwanted leaching of nanomaterials into the environment. There is also a need for guidelines to be established to protect the environment from this new type of pollution. Once research has been conducted to quantify the negative impact of nanoparticles in this setting, we will be able to establish such guidelines.
Green technology or green manufacturing offers a solution to the problem of nanoparticle pollution. This is an environmentally friendly technology, which is developed and used to conserve natural resources.
Such technology aims at producing nanomaterials with lesser raw materials, minimum energy consumption, and minimum waste production. It is known that any manufacturing process is accompanied by a large amount of waste production. This is minimized by green manufacturing, which uses green chemicals less harmful to the environment and energy-efficient processes. Microemulsions, which are used instead of VOCs in the cleaning industry, are an example of green technology.
The emerging field of “green” synthesis for nanomaterials will likely continue to develop as the world looks to harness the powerful capabilities of nanotechnology while mitigating their potentially harmful effects on the environment.
Thus, scientific authorities are monitoring various nanoparticles produced and used, as well as their subsequent impact. In the future, it should be possible to balance the technology’s benefits and possible unintended consequences.
References and Further Reading
Ian Sofian Yunus ,Harwin , AdiKurniawan , Dendy Adityawarman& Antonius Indarto (2012) Nanotechnologies in water and air pollution treatment, Environmental Technology Reviews, 1:1, 136-148, DOI: 10.1080/21622515.2012.733966
Rani K and Sridevi V. An Overview on Role of Nanotechnology in Green and Clean Technology. Austin Environ Sci. 2017; 2(3): 1026.
Arancibia-Miranda, N. et al. (2014) “Lead removal by nano-scale zero valent iron: Surface analysis and ph effect,” Materials Research Bulletin, 59, pp. 341–348. Available at: https://doi.org/10.1016/j.materresbull.2014.07.045.
Singh, J. et al. (2018) “‘green’ synthesis of metals and their oxide nanoparticles: Applications for environmental remediation,” Journal of Nanobiotechnology, 16(1). Available at: https://doi.org/10.1186/s12951-018-0408-4.
Vineeth Kumar, C.M. et al. (2022) “The impact of engineered nanomaterials on the environment: Release mechanism, toxicity, transformation, and remediation,” Environmental Research, 212, p. 113202. Available at: https://doi.org/10.1016/j.envres.2022.113202.