Nanotechnologies and Environmental Remediation

Image by Patrick Powers on Flickr

The application of nanotechnologies in land, air and water remediation has the potential to reduce the number of toxins present in our environment.

Land remediation
It is important to develop an efficient and cost effective method of land remediation. Nanofiltration technologies are being developed to remove toxins selectively from contaminated land and air. Experimental nanofilters are also being developed to purify contaminated industrial and domestic water. Research has shown that ultrafine, nanoscale powders made from iron can be used as an effective tool for cleaning up contaminated soil, by catalysing the breakdown of organic contaminants (e.g. trichloroethene, carbon tetrachloride, dioxins) to simpler, less toxic compounds.

Water purification
Nanotechnologies have actually been used in conventional water treatment for many years. Enhancements to existing treatments and novel approaches are currently being developed. The high surface areas and throughputs of nanomaterials are being investigated as ways to improve membrane technologies and the catalytic properties of some nanomaterials have the potential to neutralise chemicals and micro-organisms. Other research has shown that nanoscale iron oxide particles are extremely effective at binding and removing arsenic from groundwater (something which affects the water supply of millions of people in the developing world, and for which there is no effective existing solution). Such approaches could pave the way for a nano-aquaculture, which would be beneficial for a large number of farmers across the world.
Nanotechnologies also offer the possibility of combining sensing and feedback for example in measuring levels of contamination in various environmental media.

Air quality
There are two major ways in which nanotechnologies are being used to reduce air pollution:
Catalysts can be used to enable a chemical reaction (which changes one type of molecule to another) at lower temperatures or make the reaction more effective. Nanotechnologies can improve the performance and cost of catalysts used to transform vapours escaping from cars or industrial plants into harmless gasses as they have a greater surface area to interact with the reacting chemicals. The larger surface area allows more chemicals to interact with the catalyst simultaneously, which makes it more effective.
Nanostructured membranes are being developed to separate carbon dioxide from industrial plant exhaust streams. The plan is to create a method that can be implemented in any power plant without expensive retrofitting.

Environmental sensors
It is important to have accurate baseline data from which informed decisions on environmental issues can be made. The use of nanomaterials could produce highly sensitive sensors which could then be used to improve the quality of the local environment. The use of these sensors alongside fertiliser application may lead to a reduction in nitrous oxide releases from agriculture, which is a major cause of greenhouse gas emissions.

Managing risks and uncertainties
There are uncertainties about the intentional release of nanomaterials into the environment due to the effect that this could have on terrestrial microflora and higher organisms, and the knock on effects on surface waters. However, it is important to balance these risks against the benefits that could be realised by remediation.

Are these technologies being employed at present?
While many of the solutions described above are still under development, iron nanoparticles have been deployed for remediation purposes in many parts of the world, notably the USA. However, the UK currently has a moratorium in place preventing the use of free nanoparticles for environmental remediation purposes.

Below is a SWOT analysis summarising Government understanding, from discussion with stakeholders, of the major strengths, weaknesses, opportunities and threats facing the UK in this sector. Please help to steer future actions and shape the UK business environment by answering the questions on the right hand side of the page.