Characterisation and applications of trommel fines derived from recycling of construction, demolition and excavation wastes

Applications are invited for a self-funded, 3-year full-time or 6-year part-time PhD project, to commence in October or February.

The PhD will be based in the School of Civil Engineering and Surveying and will be supervised by Dr Muhammad Ali, Professor Mark Gaterell and Dr Bret Martinson.

The United Kingdom, like other developed nations, is constantly improving its infrastructure, towns and cities. These activities generate a huge amount of construction, demolition and excavation (CD&E) waste. Recent government statistics identified that the UK produces around 200 million tonnes of waste per year, of which approximately 60% results from CD&E waste activities. Much of this waste is typically destined for landfills, but since the awareness of the negative impacts of landfilling on the environment, enforcement of European and national legislation, recycling and reuse of CD&E wastes is becoming inevitable. Other key factors such as the policies related to the disposal of CD&E waste need further development based on scientific evidence.

Waste recycling companies segregate CD&E waste to extract recyclates, but still, a large quantity of residual waste is landfilled. This includes a potentially useful smaller fraction of CD&E waste, known as trommel fines. This is the by-product of trommel screens that pre-treat CD&E waste prior to recycling and disposal. While the UK faces landfill shortage combined with economic and environmental issues, the large proportion of trommel fines add to the waste. This calls for a consideration of sustainable options that convert this waste material into a useful resource, easing the burden on landfills. The UK Government is continuing to impose taxes on CD&E waste fines based on the volatile organic content alone but this approach is not enough to divert waste from landfills.

The primary goal of the project is to conduct in-depth characterisation studies to improve the management of CD&E fines from material recovery facilities. This project will undertake fundamental research on CD&E waste recycling processes, which involves investigations into efficient and effective material separation techniques, development of a new breed of trommel fines based construction materials such as recycled concrete, paving blocks, soil-based building materials, identify various uses in roads construction, land reclamation and will explore applications within horticultural and agricultural sectors as a plant growth media. This project will also assess environmental issues such as leaching of toxic elements from fines, which is a key to achieve the end-of-waste status for such materials.

This study also plans to evaluate the current regularity policies on CD&E wastes and will recommend improvements by establishing testing protocols for fines. Moreover, this project will undertake a life cycle assessment (LCA) of fines using SimaPro (LCA software), to quantify environmental impacts associated with the production, use, and disposal of this material. The LCA will also examine the application of circular economy, calculations for carbon footprinting, embodied energy of trommel fines in civil engineering application and identify routes for sustainable reuse of CD&E waste fines.

Fees and funding

Visit the research subject area page for fees and funding information for this project.

Funding availability: Self-funded PhD students only. 

PhD full-time and part-time courses are eligible for the UK Government Doctoral Loan (UK and EU students only).

Bench fees

Some PhD projects may include additional fees – known as bench fees – for equipment and other consumables, and these will be added to your standard tuition fee. Speak to the supervisory team during your interview about any additional fees you may have to pay. Please note, bench fees are not eligible for discounts and are non-refundable.

How to apply

We’d encourage you to contact Dr Muhammad Ali (muhammad.ali@port.ac.uk) to discuss your interest before you apply, quoting the project code ACES4510219.