Electronic nose not to be sniffed at

Professor Persaud holds one of the four sensors attached to the electronic nose

UK scientists at the University of Manchester have invented an 'electronic nose' designed to remotely monitor bad odours and methane gases at waste landfill and water treatment sites.

The device is being touted as a possible solution for communities and waste management companies, which regularly encounter problems with noisome odours and air pollution.

The electronic nose has four sensors which analyse the composition of gases in the air. The chemical profile is then sent in real time via a built-in GPS modem to a remote computer.

Based on the concentration of various chemicals, the system is able to determine whether the methane gases or odours have reached an unacceptable level. The air is then filtered before being expelled back into the atmosphere.

The researchers noted that 20.9 million tonnes, or 72 per cent, of household waste produced in Britain is disposed of in landfill sites. There are currently over 4,000 licensed sites in the UK and 80 per cent of the population live within 2km of a site.

Decomposing waste produces methane gas and odours which contribute to global warming.

The scientists claim that there is no other instrumentation sensitive enough to monitor low concentrations of odours and gases on these sites.

Gases and odours are currently analysed manually using handheld detectors and by panels of volunteers asked to "smell samples of air".

Professor Krishna Persaud, who developed the device, said: "Current methods mean that odour and gas levels are only monitored on a weekly basis. In that time bad odours can build up.

"What this device offers is the ability to monitor these levels in real time, enabling waste companies to act before levels reach an unacceptable level.

"This device has the potential to create a much healthier environment which will benefit local communities and waste management companies by alerting them to the build up of bad odours and enabling them to ensure that methane emissions remain at a safe level."

Developed in collaboration with the Silsoe Research Institute, the device has already been tested successfully at the Brookhurst Wood Landfill Site near Gatwick Airport.

Professor Persaud is also working with a major UK water company to monitor foreign chemicals and materials in water processed through water treatment plants.