On 11/11/2010 19:23, SPierce wrote:
wrote in message
...
On Thu, 11 Nov 2010 17:06:22 +1100, "0O wrote:

Greenie Desal Insanity, Just Like All Other Greenie Schemes, Will Cripple
Us

The Greens oppose desalination too.

http://bob-brown.greensmps.org.au/co...o-desalination

"....Desalination is not yet proven as a viable, sustainable option.
The effects on our environment can be horrendous (and permanent). The
people over at Get Real on Climate Change have put together a great
campaign against the proposed Victorian Desalination Plant....."


See video he
http://www.getrealonclimatechange.org/

"......Desalination is the process of removing salt and other
impurities from seawater to produce fresh water, and make it fit for
human use.

Very large quantities of sea water (11,000 litres per second, or 16
Olympic-size swimming pools every hour) are pumped into a factory-like
complex. The water is mixed with chemicals in a pre-treatment process.
This kills any animal life, and removes any solid particles that will
clog up the next stage of filters. The water is then pushed through a
series of exceptionally thin membranes in a process called reverse
osmosis.

Chlorine, caustic soda, hydrochloric acid and ferric chloride are used
during the process. Some of these chemicals are discharged back into
the sea, where some chemicals form carcinogens. Heavy metals also
contaminate the food chain....."

# If this is true...I will check it out, then I will be against any
further de-sal plants, AND protest against them. My understanding of de-sal

It is true but then the same sort of chemistry is also used to make
potable drinking water. Using chlorine to kill pathogens has the side
effect of leaving potential organochlorine carcinogens in the water but
that is always preferable to live salmonella, cholera and typhoid.

Only the chlorine input is worth worrying about and that or some other
peroxide or UV sterilising technique is essential if you want a safe
drinking water supply.

plants is that they pump sea water through membranes and discharged he salt
back into the sea where it just recycles with the other sea water and flows
away. I have no idea about chemicals being used. Never heard of it. But
it alarms me if true.

It is basically true and it is intended to alarm. Don't get too upset
about "chemicals" - not all synthetic chemicals are shock horror bad.

The RO filters have to be protected from the muck and rubbish that is in
raw seawater. It has to be buffered to the right pH and prefiltered to
remove any colloidal gunk. Much the same processes are used on potable
drinking water too. You would not be impressed if your drinking water
was cloudy and contained tadpoles or shrimps. See for example:

http://www.chemie.de/lexikon/e/Reverse_osmosis/

Main problem with it is that it is very expensive in energy usage (but
uses a lot less than the alternatives) - unless you have solar powered
distillation. Coke famously used reverse osmosis to turn Londons potable
tap water into "Dasani" bottled water so contaminated with bromate that
it was declared unfit for human consumption and withdrawn ignominiously.
ISTR they still sell it in the USA.

http://www.guardian.co.uk/business/2....lifeandhealth

Don't fall for panic attack green propaganda or the far rights trash the
planet now for fun and profit campaign either.

Regards,
Martin Brown

On Fri, 12 Nov 2010 10:51:43 +0000, Martin Brown
wrote:


http://www.chemie.de/lexikon/e/Reverse_osmosis/

Main problem with it is that it is very expensive in energy usage (but
uses a lot less than the alternatives) - unless you have solar powered
distillation.


This might solve the problem.

http://www.carnegiecorp.com.au/files...10/101028_CETO
3 Unveil_ASX 2.pdf

Start extract

The CETO system distinguishes itself from other wave energy devices by
operating out of sight and being anchored to the ocean floor. An array
of submerged buoys is tethered to seabed pump units. The buoys move in
harmony with the motion of the passing waves, driving the pumps which
in turn pressurise water that is delivered ashore via a pipeline.

High-pressure water is used to drive hydroelectric turbines,
generating zero-emission electricity. The high-pressure water can also
be used to supply a reverse osmosis desalination plant, replacing
greenhouse gas emitting electrically driven pumps usually required for
such plants.

End extract