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Clean and Green Water - Transcript

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00:00            Domestic taps – water running
                      Water in glass
                      Exteriors, Nottingham University

Guide Voice: How pure is the water we drink? Is it good enough straight from the tap – or should we use a water filter to get it that little bit purer?

Fighting pollution in the water supply is a major issue throughout the world – now researchers at the University of Nottingham in the United Kingdom have come up with a simple solution to cleaner water that is also particularly environmentally friendly.

00:23 SOT: Dr Gianluca Li Puma: “This process – its name is photo catalysis. What we actually do is we take three elements:  these are photons from light, a catalyst which is a pigment, titanium dioxide, and water. We combine all these three together; they interact with each other, and produce some species -  some reactive species -  which then can destroy organic pollutants in either air or water”

00:51            c.u. Water dripping through filter
                      c.u. carbon granules in filter
                      Water filter and water 

Guide Voice: Standard water treatment plants, much like domestic water filters, tend to use granular activated carbon to soak up pollution such as pesticides and oestrogens that can find their way into the water system. These chemicals are then burnt off – but can result in noxious chemicals entering the atmosphere – so the pollution moves from the water to the air.

01:13 Dr Gianluca Li Puma: “To drive this process you can actually use  solar radiation,  so in a way it’s a green process -  an environmentally friendly process -  which uses sunlight to photo-activate the catalyst. It can be used either in industrialised countries  to purify drinking water from trace organic pollutants such as pesticides, endocrine disrupting chemicals or any small amount of inorganics. Also, it can be used to treat waste water. For example, the European Union will be tightening the level of discharge of pesticides and other organic pollutants into the water, so they need new technologies to deal with this – this is one they can use. In developing countries this system can be used also to supply very cheap drinking water in remote areas.”

02:14            Water in photo-catalytic reactor
                      Water & Titanium Dioxide slurry in tank, panning to reactor
                      c.u. PhD Student
                      2 shot – Dr Li Puma with student
                      Tilt down from Dr Li Puma’s face to writing pad
                      c.u. writing notes
                      Pull out – students at reactor; Dr Li Puma adjusting water flow
                      c.u. hand on valve control
                      c.u. Dr Li Puma at valve control
                      c.u. student looking into reactor
                      c.u. and pull out from nozzle to show water in reactor  

Guide Voice: The “Fountain Photo catalytic Reactor” being researched at Nottingham University combines titanium dioxide, an inexpensive white powder, used as pigment in paints and also in products such as toothpastes and sunscreens, with water under UV light, in this case supplied by ultra violet lamps.

The water and catalyst are pumped through a specially designed nozzle, producing an umbrella shaped water fountain, creating a canopy that maximises the absorption of UV light resulting in a more effective removal of persistent contaminants, such as pesticides and pharmaceutical residues. The catalyst can be recovered and re-used after passing to a settling tank.

The system does require UV light to work; the cheapest and most efficient source being sunlight, which could be a problem in some countries.

03:04 SOT: Dr. Gianluca Li Puma: “Definitely, by using sunlight the cost will be reduced by at least 10 times. But you need to have the sunlight available, so it will be fine for a country like Egypt that has lots of sunlight, or Mexico, but for northern countries then you still need to be using UV lamps. So perhaps the applications are different here – we can use the sunlight system to purify water in developing countries and then we use this technology for indoor air purification in northern countries or in the Northern Hemisphere”.

03:41            Ends

Page contact: Tom Abbott Last revised: Fri 1 Apr 2005
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