Waste Minimisation and Re-Use

The disposal of waste is becoming an increasingly difficult problem. One way of solving this is to create new ways in which waste materials can be used. We are investigating a variety of waste products to find suitable applications for them in construction and for pollution control purposes. We are also investigating the sustainability of such uses. Such applications include construction fill, construction aggregates, building materials, sorbents, drainage materials, landfill liner and cover materials etc. We are also looking at the use of waste materials from one process as raw materials for another.

Some of the wastes which are being investigated include:

Shredded tyres:

40 million tyres were discarded in the UK in 2001 and this is likely to increase to 50 million by the year 2010. The disposal to landfill of whole tyres will be banned in 2003 and of shredded tyre in 2006. Tyre has been used successfully in playground surfacing and in concrete road bollards. More recent innovative applications have been as lightweight fill and as part of liners and drainage systems in landfills. A novel application, currently being investigated, is their use as binders in the sorption of hydrocarbon contamination.

Sewage sludge:

1million tonnes of dried sewage sludge is produced every year resulting from 26 million tonnes of raw sewage sludge. Of the dried sewage sludge 20% is incinerated, 15% is dumped at sea and 10% is landfilled. The dumping of sewage sludge at sea was banned in 2000. Hence there is scope for innovative solutions to deal with 50% of sewage sludge arisings. One novel application being investigated is the use of dried sewage sludge in the stabilisation of other waste and in particular mine tailings.

10 million tonnes of fly ash are produced annually in the UK of which 1.5 million tonnes is reused, mainly in construction related applications (e.g. replacement for cement, structural fill, grouting mixes, and minerals filler in asphalt paving). There are many areas which can be investigated for reuse of ash including: production of zeolites, sorbents, glass and composite materials, absorption and waste stabilisation and also agricultural applications.

Construction and demolition waste:

70 million tonnes of construction and demolition waste are produced each year of which 24 million is 'hard' waste (mainly concrete, brick, tile, clayware and stone) and the rest is 'soft' waste (excavated spoil, dredgings). Various reuse and recycling options for this waste on site are being considered.

Minerals waste (mining and quarrying):

Mineral waste arisings are around 120 million tonnes/year which includes 16 million colliery, 9 million coal, 50 million clay and 47 million quarrying. Mine tailings are being stabilised with various binders including cement, ash, dried sewage sludge and the feasibility of developing the resulting materials into beneficial products is being investigated.

A Faraday Partnership on Industrial Waste Minimisation (Mini-Waste) has been established.

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Telephone - +44 01223 332715

Other environmentally related projects:

Remediation of Brownfield sites

Treatment of contaminated land with in-ground barriers

Geoenvironmental response to climate change

Geoenvironmental sustainability