Assessing the Environmental Costs and Benefits of Resource Recovery Approaches for Nanomaterials in Future Waste Streams

Nanomaterials (NMs) are typically regarded as materials that have one or more dimension of < 100 nm in size. Due to their extremely small size, nanomaterials exhibit properties that are vastly different from their 'bulk' chemical. These novel properties are therefore currently being exploited in a wide range of products, including pharmaceuticals, cosmetics, coating materials, electronic items and catalysts and a number of other applications are in the pipeline such as use, gene therapy, food packaging, advanced tyres, semiconductors and for use in bioremediation of contaminated environments. Nanotechnology is therefore a very rapidly growing sector of the material manufacturing industry that has already captured a multibillion market and by 2015 this market is forecast to be worth 2 trn Euro.

As the nanotechnology sector increases in size, the amounts of NMs released to waste streams will increase and the types of NMs in waste are likely to become more diverse. Increases in NM concentrations in waste streams might affect the performance of some waste treatment methodologies or the acceptability of a waste product to an end user. As many waste products (e.g. animal manures and slurries, compost, sewage sludge and anaerobic digestate) are applied to the natural environment as fertilisers and soil conditioners, it is likely that emissions of NMs to the environment will increase and this could result in adverse impacts on organisms in the environment and on the services that the natural environment provides. Many of the NMs are produced using expensive, low yield production methods resulting in large volumes of waste and/or are made of rare elements where available resources are under threat of depletion. The development of approaches for recovery of NMs could offer a wide range of benefits in that they could begin to address the problem of resource depletion and would result in reduced emissions of NMs to soils and water bodies thus reducing potential impacts on the environment and the delivery of the associated ecosystem services. However, while a wealth of work is now being performed on the hazards of NMs to the environment and human health, limited work is being done on NMs in waste and on methods for recovery of NMs from waste streams. With the continued rapid growth of the nanotechnology sector, there is therefore a real need to understand the potential risks associated with NMs in different waste products to the environment and ecosystem service delivery and to develop recovery and other waste management approaches for controlling these risks.

This catalyst project, involving leading experts in nanotechnology, green chemistry, bioremediation, environmental chemistry, ecotoxicology, ecology and environmental economics from the academic, business and government sectors, will therefore synthesise knowledge on the nature and amounts of NMs in waste streams in the 2020s, the potential impacts of these NMs on the health of the environment; and potential approaches for recovering NMs from different waste types. The project will involve a detailed review of the literature and expert interviews as well as an expert workshop. A stakeholder workshop will be staged to promote end user engagement in the project. The key outputs of the project will be a publication in a high impact journal and a highly innovative interdisciplinary proposal for submission to the second phase of the NERC funding programme.

The project will benefit a range of stakeholder including industry, policy makers and regulators and members of the waste treatment and management sectors. Industries manufacturing and using nanomaterials in commercial products will benefit from our research by gaining a greater understanding of how nanomaterials that they produce or use in their products may enter waste streams and the environmental implications of this. Using this knowledge it may be possible to modify procedures or products to reduce loss of nanomaterials to waste streams or to reduce the potential impacts on the environment and / or human health. This should assure the commercial viability of the industry in light of potential risk-avoidance based legislation. The policy and regulatory sectors (e.g. Defra and Environment Agency in the UK and European Agencies) will benefit from an improved understanding of the potential risks of nanomaterials entering the environment and harming human health via the waste stream. This can inform evidence-based policy on waste management. Members of the waste treatment and management sector (e.g. water companies, incinerator operators, composting operations, anaerobic digestor operators and landfill operators) will benefit from an increased understanding of the presence of nanomaterials in different waste streams and methods of recovering value from these waste streams. Thus they should derive an economic benefit from the research. In addition, the research should inform this sector of potential risks to existing waste treatment processes due to the presence of nanomaterials and methods of reducing these risks ensuring business continuity in light of the changing nature of waste streams. The project will also deliver wider benefits to human wellbeing and the health of the natural environment by developing an understanding of the potential adverse effects of nanomaterials contained in waste on humans and the environment and by developing environmentally-sustainable options for mitigating against these effects where appropriate. This will mean that society will be able to benefit from the novel properties that are offered by nanotechnology without causing adverse impacts in the natural environment.