Practical approaches to address non-dewatered alum sludge properties and benefits of dewatering

James Mae Group
University of Bradford

Removing waste from waste-water treatment with better energy recycling

Water purification and waste-water treatment is necessary to both the provision of clean drinking water and the preservation of healthy rivers and coasts. Modern processes of purification and treatment involve the use of aluminium salts which help remove solid particulates from water, and in the doing so produce the by-product ‘alum sludge’.

Nicholas’s project will investigate new methods of dealing with the waste product, to tackle issues with its disposal such as overfilled landfills, environmental pollution and its carbon footprint. Traditionally ‘alum sludge’ is dewatered by centrifugation (dehydrated to remove some water) so that it is made more compact, easier to transport and easier to dispose of. However, this process is energy intensive, and so Nicholas is looking to improve the freeze-thaw process of dewatering. He will investigate the feasibility of using the energy generated by freezing sludge to then thaw it later. Such a system would be self-sustaining and reduce energy consumption significantly.

The impact of this research on the environment would be significant in the long-run by making huge efficiency-savings in energy use across the entire country if implemented. Nicholas will be working closely with the UK’s water companies to perform research on their ‘alum sludge’ and provide mutual support for their energy-saving efforts. The research will also explore efforts to recover chemicals from the waste by-products and explore construction industry applications.

Nicholas graduated with a first class Master’s degree in Chemical Engineering from the University of Bradford, but his work in the field of engineering began in a research laboratory in Zimbabwe. Nicholas began his work in partnership with the University of Bradford and James Mae Group as KTP Associate Process Engineer in 2020.


“Water treatment is a necessary but energy expensive process, and with the support of the Commission my research will be focussing on making energy savings wherever possible.”