The article will assess the biodegradability of CNTs and will also feature associated topics such as
- Biodegradation
- Recycling
- Disposal
- Applications
Are CNTs biodegradable?
Yes, CNTs are biodegradable. CNTs, even though they are regarded as fairly stable, can be degraded by microbes, macrophages, and enzymatic actions.
It is speculated that CNTs may release harmful substances (acting like asbestos) and therefore it is preferred that CNTs may be incinerated. The incineration may, however, cause further environmental problems such as a decrease in air quality.
CNTs are termed hazardous because of the medical complication rendered by CNTs waste including lung inflammation and even cancer. However, this can not let us be oblivious of the positive outcomes of CNTs use such as increased productivity, improved durability, less waste, and energy conservation.
What is biodegradation?
Before we advance, let us revisit some basics so that there is no room left for any sort of ambiguity or equivocality.
Biodegradation can be explained as the breakdown that is caused by the action of microbes. The microbes may include names such as bacteria, fungi, algae, and even viruses.
The process of biodegradation can be simplified into basic steps and the overall purpose is to convert the waste into simpler material so that the waste does not add up.
The simpler materials that are formed as a result of biodegradation can assimilate back to natural cycles leaving the net waste zero.
However, biodegradation requires certain properties or prerequisites. These include
- The material should be natural
- The material should be sourced from nature
- The material must be organic
- The material should be degraded by microbes in 180 days or less
- The material should be eco-friendly
What are the disposal methods for CNTs?
When it comes to disposal, two main processes get highlighted. These include incineration and landfilling.
Incineration
One common method to dispose of CNTs is to incinerate them. This is mainly because there are various controversies when it comes to the topic of CNTs. Many claims that CNTs lead to the release of certain particles that may be hazardous to human health and the environment.
This means that carbon nanotubes may act as an asbestos material that may cause:
- Respiratory problems
- Lung scarring
- Fibrosis
- Lung inflammation
- Asthma
However, proper research is still underway. To be on the safe side, it is suggested that carbon nanotube waste must be categorised as hazardous waste and should be incinerated. When carbon nanotubes are incinerated, the risk of contamination and release of unwanted particles will be eliminated.
However, to ensure this, you must incinerate CNTs at higher temperatures (more than 850 degrees Celsius) for an appropriate period of time.
The burning or incineration of carbon nanotubes would lead to other environmental issues, however. This is because when waste is burnt or incinerated, there is a release of harmful gases and fumes.
One of them is carbon dioxide among other greenhouse gases. There will be an increased emission of pollutants and toxins.
This may reduce air quality and cause respiratory problems for nearby populations. Also, the release of GHGs such as carbon dioxide would lead to environmental anomalies such as global warming, unseen weather patterns, decreased tree count, acid rain, ozone depletion, medical complications et cetera.
Disposal in landfills
Disposing of material in landfills is a common procedure to deal with both biodegradable and non-biodegradable waste. A landfill site or garbage dump is a controlled environment for the discarding of waste material so that there are minimal impacts of the waste on the environment.
However, since there are mixed reviews about the release of harmful materials from CNTs, many researchers believe that it is not wise to dispose of CNTs in a landfill site. The possible release of substances from CNTs may cause the degradation or transformation of polymers.
This can contaminate the other waste and may also put the surrounding areas and nearby people at risk of exposure and detrimental impacts such as respiratory issues, asthma, and pulmonary fibrosis.
Can you recycle CNTs?
Yes, you can recycle CNTs to make sure that the disposal methods are not relied upon as it has been assessed that the disposal of CNTs may be linked with environmental and health-related negative and detrimental effects.
A lot of contemporary researches have been done and several recycling methods have sprouted that include
- Degradation
- Dissolution
- Pulverisation
The adoption of these processes will ensure that CNTs do not end up as waste. This will reduce waste generation and will also decrease the environmental problems associated with CNTs.
Are CNTs hazardous?
Yes, CNTs are categorised as hazardous waste because of the negative and detrimental effect rendered by CNTs. It is argued that CNTs may emit asbestos type material which can cause serious medical complications such as lung issues, fibrosis, and even cancer.
Because of these complications, the waste generated by CNTs must be categorised as hazardous so that the complications may be avoided. The best disposal therefore, is to either discard the CNT waste in red-coloured bins or resort to hazardous waste collection programs where the waste will most likely be incinerated.
What are the positive inputs by CNTs?
You may wonder what is the significance of CNTs. In other words, why are CNTs used? CNTs are used to increase the efficiency of production materials such as cars, automobiles, planes et cetera.
It has been researched that CNTs can be incorporated in most of the present day materials. The addition will lead to benefits such as increased yield, better productivity, decreased energy use, and reinforced durability.
This will directly affect the environment in a positive way because the effects mentioned will lead to resource conservation and decreased waste generation.
Conclusion
It is concluded that CNTs, even though they are regarded as fairly stable, can be degraded by microbes, macrophages, and enzymatic actions.
It is speculated that CNTs may release harmful substances (acting like asbestos) and therefore it is preferred that CNTs may be incinerated. The incineration may, however, cause further environmental problems such as a decrease in air quality.
CNTs are termed hazardous because of the medical complication rendered by CNTs waste including lung inflammation
and even cancer. However, this can not let us be oblivious of the positive outcomes of CNTs use such as increased productivity, improved durability, less waste, and energy conservation.
References
- Dai, H. (2002). Carbon nanotubes: opportunities and challenges. Surface Science, 500(1-3), 218-241.
- Boczkowski, J., & Lanone, S. (2007). Potential uses of carbon nanotubes in the medical field: how worried should patients be?
- Liu, Y., Zhao, Y., Sun, B., & Chen, C. (2013). Understanding the toxicity of carbon nanotubes. Accounts of chemical research, 46(3), 702-713.
- Graphene Nanotubes. Retrieved from: https://ocsial.com/sustainability/#:~:text=Thanks%20to%20their%20unique%20physical,reach%20a%20carbon%20neutral%20society.
- Wang, S., Zhao, J., Wang, Q., & Zhang, D. (2022). Preparation and Recycling of High-Performance Carbon Nanotube Films. ACS Sustainable Chemistry & Engineering, 10(12), 3851-3861.