Bacteria and nanofilters -- the future of clean water technology

Feb 22, 2008

Bacteria often get bad press, with those found in water often linked to illness and disease. But researchers at The University of Nottingham are using these tiny organisms alongside the very latest membrane filtration techniques to improve and refine water cleaning technology.

These one-celled organisms eat the contaminants present in water — whether it is being treated prior to industrial use or even for drinking — in a process called bioremediation.

The water is then filtered through porous membranes, which function like a sieve. However, the holes in these sieves are microscopic, and some are so small they can only be seen at the nanoscale. Pore size in these filters can range from ten microns — ten thousandths of a millimetre — to one nanometre — a millionth of a millimetre.

These technologies can be developed into processes which optimise the use of water — whether in an industrial system or to provide drinking water in areas where it is a scarce resource.

The research is led by Nidal Hilal, Professor of Chemical and Process Engineering in the Centre for Clean Water Technologies — a world-leading research centre developing advanced technologies in water treatment.

Current membrane technology used in water treatment processes can decrease in efficiency over time, as the membranes become fouled with contaminants. By using bioremediation the membranes can be cleaned within the closed system, without removing the membranes. Researchers at the centre have developed the technology in partnership with Cardev International, an oil filtration company based in Harrogate.

As well as being highly effective in the water treatment process, transforming industrial liquid waste contaminated with metals and oils into clean water, ultrafiltration and nanofiltration membranes have a useful side effect. The waste products have a very high calorific value, and can be used as fuel.

Nanofiltration and ultrafiltration membranes are also being used in work funded by the Middle East Desalination Research Centre, which looks at creating drinking water from seawater. By pre-treating the seawater and removing contaminants, the membranes reduce the fouling of machinery in the next stage of the process — whether through reverse osmosis or thermal desalination. This can prevent damage to the machinery, reducing the need for expensive repair and replacements.

And by measuring liquid properties at the nanoscale, using state-of-the-art atomic force microscope equipment at the University, researchers are exploring how liquids behave at an atomic level — how they flow and pull apart. These results could be used in mechanics and industry, for example, maximising the use of oil in an engine.

Liquids are also being tested at a range of temperatures, from the very low (-50 oC) to the very high (150 oC).

Professor Hilal said: “Examining the properties of liquids has never been done before at this scale.

“By using bioremediation and nanofiltration technology combined, the water cleaning process is integrated — using far less energy than current processes. Add to this the recycling of waste products as fuels and you have a greener technology.”

Source: University of Nottingham

Explore further: Tissue regeneration using anti-inflammatory nanomolecules

add to favorites email to friend print save as pdf

Related Stories

New type of solar concentrator desn't block the view

4 hours ago

(Phys.org) —A team of researchers at Michigan State University has developed a new type of solar concentrator that when placed over a window creates solar energy while allowing people to actually see through ...

Cities, states face off on municipal broadband

4 hours ago

Wilson, N.C., determined nearly a decade ago that high-speed Internet access would be essential to the community's social and economic health in the 21st century, just as electricity, water and sewers were in the previous ...

Recommended for you

Tissue regeneration using anti-inflammatory nanomolecules

12 hours ago

Anyone who has suffered an injury can probably remember the after-effects, including pain, swelling or redness. These are signs that the body is fighting back against the injury. When tissue in the body is damaged, biological ...

Cut flowers last longer with silver nanotechnology

Aug 21, 2014

Once cut and dunked in a vase of water, flowers are susceptible to bacterial growth that shortens the length of time one has to enjoy the blooms. A few silver nanoparticles sprinkled into the water, might be the answer to ...

Relaxing DNA strands by using nano-channels

Aug 20, 2014

A simple and effective way of unravelling the often tangled mass of DNA is to 'thread' the strand into a nano-channel. A study carried out with the participation of the International School for Advanced Studies ...

Сalculations with nanoscale smart particles

Aug 19, 2014

Researchers from the Institute of General Physics of the Russian Academy of Sciences, the Institute of Bioorganic Chemistry of the Russian Academy of Sciences and MIPT have made an important step towards ...

User comments : 0