On 4/1/2002, Ray Stephens posted:

Water water everywhere....

What handicaps are there to distilling megalitres of sea water, using towers the size of those used for petroleum, environmentally situated and powered by tides and electrolysis between extracted ions and metal plates [?](what to do with tonnes of sodium chloride?) and pumping the stuff by pipes into a half million kilometre piping grid covering a nation?

I know that Saudi Arabia is getting a lot of their fresh water from sea water. Why is the idea of distilling oceanic water -there is plenty of it- reduced to evaporation ponding and none?


Toby Fiander added:

... and tastes terrible apparently. I think a proportion of the fresh supply is actually seawater.

For a reclaimed water project I was involved in years ago, Doha had sewage which was so saline that it was not possible to germinate lucerne without special arrangements, and there was a significant yield depression. Energy for irrigation there, and presumably other Gulf countries, was valued at about 1c/L of diesel. So it was considered reasonable to have smaller pipes for irrigation purposes than would normally be used.

Stuart Ridley noted:

Don't you know that Penrice (old ICI) uses salt in vast quantities for the manufacture of soda . There are large salt pans at Dry Creek, just 15k out of Adelaide. They flood the shallow pans with seawater and let nature take it's course. Sodium chloride is one of the most  used chemicals in general manufacturing.

Peter Macinnis commented:

Ray, what are you going to make with all that salt?

Have you thought about CO2 emissions?


Toby Fiander added:

There is some attraction in using the solar collection capabilities of salt ponds themselves to drive the evaporation
process. The stratification in them can retard the drying process. The wind across a shallow saline lake can disrupt the stratification, too.

The only trouble is, salt is worth so little, and land on which to dry it is so plentiful around Australia, I am not sure why you would bother with clever technology.

Using the stratification to produce low-grade heat for some process is probably the way to go. I think the Pyramid Hill group are investigating this. I am never quite sure what they are doing, which makes me all the more suspicious of whether there is a buck in it. Perhaps we await Senator Minchin's initiative as a result of the caining he and others get in 4C.... don't forget to watch, the transcript is worth the effort, too.

I am never quite sure what they
are doing, which makes me all the more suspicious of whether
there is a buck in it.

Gregg Reynolds said:

Once market demand for salt has been satisfied, I imagine a worthless overproduction could simply be returned to the sea. I assume it would be a literal "drop in the ocean".

> Have you thought about CO2 emissions?
>

Peter Macinnis, to Ray

Brief point: you need energy: where is it to come from? It will either be fossil fuels which generate CO2, or some renewable source that imposes huge hidden CO2 costs -- I think Ian Lowe estimated that it takes 300 years to recover the carbon costs of a dam and hydroelectric generation kit.

In simple terms, Ray, I think you have assumed that energy -- or some energy -- is free.


Ray to Peter:

Peter, wind and Sun and tides are free energy.
It is only the machinery to harness them which costs. :)
-plus I was also thinking along the lines of chemical energy from ion flows in a concentrated electrolytic solution. (most chemical reactions are exothermic too)

Apparently NaCL can make NaOH and HCl (thanks Gerald), but I have no idea of the cost efficiency of this? Lead or zinc plates (or something) and you got a wet-cell battery.

> Apparently NaCL can make NaOH and HCl (thanks Gerald), but I have no idea of

> the cost efficiency of this? Lead or zinc plates (or something) and you got

> a wet-cell battery.

Ray responded:

That, Peter (Toby and Forbzy) is about the extent of it.

I feel like quoting James Douglas Morrison:
"No eternal reward will forgive us now for wasting the dawn"

It isn't as if a snails pace toward fortifying Australian (and global) water resources will provide much relief before this century is done. At least, not in so far as any major developments are obvious to me anyway.

Maybe not, seems I did not express myself well enough. I was referring to likely future techniques. It seems to me that wave power has the highest concentrated and most consistent energy availability but others may differ.


The too hard basket is bursting at the seams, and there is a hole in my bucket dear Jounny, dear Johnny, a hole in my bucket.


Gerald Cairns noted:

I don't have any statistics to offer but the salinity of the ocean varies considerably with time and location and a large part of this is caused by evaporation which forms the precipitation, which in turn washes out of the land yet more salt to the ocean, assuming of course we let the rivers flush themselves that is!

I doubt that desalination plants would have more than a minor local effect and the brine could be discharged to an appropriate point where it will do least harm. I think wave energised reverse osmosis plants are probably going to be essential sooner than later. There is still a lot we can do to feed ourselves while minimizing the impact on the environment but don't take this as an argument to continue to grow the population indiscriminately.
and:

Hi Stuart,
It is also a starting point for hydrochloric acid production, which results in large volumes of sodium hydroxide as a by product.

In the thread "New Old Water for Perth, on 6/1/2003, Toby Fiander wrote:

The Western Australian government is proposing to move away from the desalination option due to the operating cost, which would increase water charges. Instead it is proposing to develop huge groundwater reserves. The only trouble is the environmental cost is unknown.

Maybe not, seems I did not express myself well enough. I was referring to likely future techniques. It seems to me that wave power has the highest concentrated and most consistent energy availability but others may differ.

The article below is from the Sunday Times.

I wonder if the Government is yet prepared to charge the marginal cost for water by volume? ...or properly control groundwater use from the surface aquifer? ...or promote xeriscaping? ...or retrofit low water use fittings in houses at no cost? ...or roof the reservoirs of the Goldfield's Water Supply system ... etc... etc... Most of these are probably cheaper options than developing a new source, as is usually the case for demand management measures.


SUNDAY TIMES ARTICLE
Taps shut on saltwater bid
By GRAHAME ARMSTRONG
29Dec02
DESALINATION has been ruled out as a fix for the state's water crisis because it is considered too costly - for taxpayers and the environment.

The State Government is turning its attention to deep aquifers in the South-West to safeguard WA's water future.

A desalination plant, proposed for Kwinana or Rockingham, would cost $205 million to build and up to $30 million a year to run.

The Sunday Times has learnt that the higher-than-expected operating costs would put pressure on the price of water and was a principal factor in the government's move away from desalination.

The suggested desalination plant would also emit five times more greenhouse gases than extracting water from the ground and had a lifespan of only 25 years. And it could not, as first thought, simply be switched off and used only as a back-up in times of drought.

A desalination plant would have produced about 30 gigalitres of water a year.

The Water Corporation is spending $6 million to determine how much water it can safely draw from the ground, but the Government is confident it can extract up to 44 gigalitres a year from the Yarragadee basin, which holds an estimated 480,000 gigalitres.

In an average year, Perth and the Goldfields use a little more than 300 gigalitres.

"The best option is to proceed with extracting from the aquifers because they're so huge," a Water Corporation source said.

"It stands to reason, if you've got an aquifer of that size (480,000 gigalitres) and you've got reliable rainfall in the area that recharge is going to be more than sufficient.

"The advice we've got is that the water is more plentiful and more easily extracted in the South-West basin of the Yarragadee than the north."

The Sunday Times revealed in September that the Yarragadee aquifer is so big it holds enough water to serve Perth for 1600 years - but no one at the Water and Rivers Commission could say how much water could be drawn without damaging the environment.

Although Cabinet has yet to make a formal decision to shelve a taxpayer-funded desalination plant, most of the advice it is getting is negative.

But it is still possible that a privately funded desalination plant and pipeline will be built in Esperance, supplying water to Kalgoorlie-Boulder and the Goldfields.

The government's change in direction comes after the Environmental Protection Authority in October cleared the way to build the plant at Kwinana or Rockingham.

Authority chairman Bernard Bowen said a desalination plant producing 30 gigalitres a year could be managed without adversely affecting water quality or marine life in Cockburn Sound.

"Greenhouse and nitrogen oxide emissions are not expected to be large," Mr Bowen said at the time.

[ends]

On 28/2/2003, in the thread "Economics of Desalination", Toby Fiander posted:

Engineering World has just published an interesting article by four blokes from Kuwait and the IAEA (Ettouney, El-Dessouky, Faibish and Gowin).

It covers a range of interesting stuff, including a literature review, an assessment of annual and longer term costs and the three thermal processes:

• multistage flash desalination,
• multiple effect evaporation with thermal vapour compression and without MEE,
• mechanical vapour compression.

It also looks at reverse osmosis. MSF and RO processes dominate the market for both brackish water and seawater desalination.

There is no discussion of site specific factors that I can see, like where the waste stream goes, so it is a rough guide only. But it gives examples, which are interesting if not instructive.

The article concludes:

• there are considerable economies of scale,
• for RO costs are roughly equally divided between fixed items, power costs and membrane replacement costs,
• fixed plus energy costs are about 40-50% of total unit product cost for the MSF and MEE processes,
• RO is best suited to low salinity feedwater.

The article is a reprint, like much of what appears in Engineering World. This one appeared in Chemical Engineering
Progress, the magazine of the American Institute of Chemical Engineers in December, 2002.


On 17/6/2004, Kirstin Harris wrote in the thread "Desalination":

Does anyone remember a prgramme on (I believe) ABC RN (it could have been in NewScientist, but I have no visual memory of the article only a verbal one, so probably not) sometime in the last 3 yrs on a project in the Middle East somewhere on the coast that was taking sea water, desalinating it without using heaps of electricity and then using the resultant water to irrigate market gardens?



Kirstin asked:

What to make the clean water or made out of the resultant produce?

My (also vague) recollection was that the $$ made from the produce vastly out weighed the $$ used to set up the system as the actually desalination was done by evaporation and condensation using solar energy and clever uses of air pressure rather than electricity to do the heating of the salt water, with the remaining brine being pumped back to the sea.... does that sound about right?

Anyway, thanks for the clues, I'll have a better idea of where to start looking now.


David Maddern added:

There are also beads which attract single positive ions and need cyclic flushing. One I was looking at some months ago used 400VDC , something like 12 atmosheres on the H20 going in .

Priciple may be called 'gel exchange' I cant look it up as I have has a hard disk crash between then and now


Zero Sum commented:

You'd lose that bet Gerald.

I recall the thing she is talking about and it is based on very primitive technology elegantly applied. It was a straight evaporation job.

But I believe they then extracted something from the brine too...


Richard Gillespie answered Kristin:

There was such an article in New Scientist, vol 131, issue 1784, 31 August 91,  page 37. I think there was a more recent one too, but can't find it now.


Toby Fiander replied:

A pressure of up to 400m head is applied to drive the process in the opposite direction, hence it is called REVERSE osmosis. It is energy intensive and there are also membrane integrity issues in the long term, the membrane is also affected by clogging with certain compounds and even elements, and the biflow required to make sure that membrance clogging is minimised is often a significant problem both from the point of view of the efficiency and from the point of view of disposal. What do you do with a flow of highly saline water in an inland place? Even with all these problems it is a great little technique - membrane manufacturing processes were pioneered in Australia, even if US Filter (and whoever bought it from the French) now owns the intellectual property.

Have a look here:
http://www.gewater.com/library/tp/833_What_Is.jsp




On 20/7/2005, Toby Fiander posted:

The SMH reproduces some figures for the cost of the desalination plant in this article:
http://smh.com.au/news/environment/plant-threatens-to-double-sydney-water-bills/2005/07/19/1121538975644.html
or
http://tinyurl.com/e3cn8

The argument revolves around the contention that water will cost $2.44/kL, instead of $1/kL which is what it is now.  But calculated in the  same way, a typical water user pays about $2/kL now.  It is just not charged that way at the moment.  There is a good argument that it should be, and immediately, not in little increments so that no one notices.

Because I am a frugal water user and most of the bill comes in fixed charges, I pay much more for water than $2/kL.  As a careful water user I am heavily penalised.

The SMH misunderstands how the difference between marginal pricing and average pricing... look, I could go into a detailed critique, but frankly, who cares?  It is clear sensible water charging policy is beyond the ability of the Government and its econocrats, let alone the understanding of the SMH.

On 3/4/2005, in the thread "Bitter Taste of a Technology Policy Desert", Toby Fiander posted:

It is about 12months too late to make the decision, but apparently Sydney is to have desalination. What an admission of defeat!

Frank Sartor has done a fair job of getting demand under some sort of control, but all too late, and with one hand behind his back, because the price of water is still only $1 a tonne delivered to the door.

What is worse, internally Sydney Water still doesn't get it. The success of the leakage detection program is not compared to the cost of a new supply, but to the cost of reticulation alone, mere cents a kilolitre. It is still a successful program in these terms, which shows how little effort has actually been put into demand management generally.

If the best innovative program Sydney can come up with is rainwater tanks, then there is no hope really.

Here is someone else whingeing about it too:
http://tinyurl.com/byulh


On 6/6/2005, Toby Fiander posted, in the thread "Where to Desalinate and other things":

The SMH has a graphic showing two possible locations very vaguely for desalination. A rather dense-headed local member from around here was in the paper suggesting that some of Sydney would get supplied from this new water source and the rest would have to make do with a dwindling supply from the rest of the system. This shows a misunderstanding of probabilities, but I suppose one can't expect a lot from politicians.

I reckon there are at of other options besides the two options shown in the SMH graphic. For example, why not use a site near Wollongong? It would then be possible to pump the water to, say, Cordeaux Dam and pass it throughout Sydney - given that it is distilled water which has some human health problems of its own, this has considerable merit, I think.

Peak load gas plants for electricity generation have been discussed for Tallawarra, Bamarang, Tomago, and Munmorah. The Tallawarra option has considerable merit for lots of reasons. To recover from a system collapse, the favoured strategy used to be to start a turbine at the Snowy and energise a line to Canberra, then a line to the Illawarra and start the Tallawarra Power Station (then running on Huntley Coal), but this does not exist any more and so there would have to be a complicated arrangement of energising lines and placing loads on the system to match, so that some power could get to the Central Coast, Western Coalfields or to the Hunter Valley to so the power stations there could start.... it might take quite a while, and given that the estimate of how long it would take with Tallawarra still there was about 24h, assuming it is possible at all, the procedure now could take a few days. Replacing Tallawarra with a gas powered plant would have some merit, possibly. But there is another interesting twist.

Last night's 38 Minutes program (with 22minutes for advertising) outlined that nuclear power is a possible option for desalination. It probably ought to be in the desert, but dry cooling is pretty expensive, so what if the Tallawarra option was a nuclear one? Pumping to the Sydney supply dams in the old scheme would then be relatively easy.

I think Bob Carr is a braver politician than I gave him credit for, but I wonder if his bravado extends this far. Anyway, if anything happens, you heard it here first.


Garry Dalrymple replied:

I do not think that Bob the builder or uncle Frank are being the slightest bit brave.

I think the Desalination / Sewage re-cycling announcements are 'Political Theatre' in the service of Issue Management.

Well before any concrete is likely to be poured for iether project residents East and West will be strongly motivated to initiate home rain watertanks which will 'personalize' water use frugality. Seeing your home tank less than half full has much more impact on a consumer's domestic water profligacy than worries about Warragamba or arguments about how much natural flow the Hawkebury / Shoalhaven rivers need for good health.

I mean would the 'Bottled water' and 'Home filter' generation choose to drink ex-salt water or ex-sewage if for a few hundred dollars you could have 'untouched by human hands' rain water?

Home tanks can be subtly encouraged by non-financial incentives to be a 'good thing' whereas the sensible and economically rational reaction of just doubling the cost of water each quarter until demand reduces to match remaining supply (forcing an identical degree of home water tanking) is a head of political negatives, hitting 'battlers' or coercing limited water use.

The Nuclear option is a masterstroke, any proposal for a Nuke powered anything faces at least a decade of enquiries, reviews appeals and focusses 'community action' on the powerplant itself rather than on what the problem that the project is supposed to address; the sustainability issue of current water use levels.

All announcements to date have been a big stalling act, as stalling acts are sooooo much cheaper than actually doing anything that costs real money or making decisions that affect citizen's water use options.

The State government is banking on some rain some time before the next election or before it is necessary to commit big money to contracts.

Look forward to even more enquiries and reviews ..... Until the drought breaks.

> Statistics can be tortured to confess to just about anything.
> An awkward, unscientific lie is often as ineffectual as the

> There is nothing more disturbing than a sharp image of a fuzzy
> concept

Gerald Cairns observed:

Never had any experience of cleaning RO units but I imagine that a very small amount of citric acid would very rapidly release the calcium salts. The volume of feed water required may be governed by the tube volume to surface ratio, however.


Toby Fiander replied:

I would be interested in your link about Israeli work when you find it again.

The plants in Qatar and elsewhere we have referred to on this list previously use flash distillation, I think.

Interestingly, there are products on the market used in sewage treatment which use membrane technology but only under gravity head. The principle is apparently similar to the arrangements used at higher pressures. The technology is new to Australia - there is a truckstop near Lithgow with a small plant and a number of household scale units are under test. It is marketed under the brand name Aquacell, I think. Needless to say, there is resistance to the price, but clean water always comes at a price.


Toby Fiander said:

If the installed generation capacity is about 10% more than the plant actually uses, then that is about the same as some of the others, with about 2.4kWh / kL of water produced, which was what was produced in practice about 10years ago. I suppose it is possible to do a little better now.

It seems that the energy requirement at about 280m head difference is apparently about 0.75kW.h / kL, with commercial
membrane technology. But there are other processes in a treatment plant besides the desalination, and I understand that practical efficiency can vary over time.


Gerald Cairns replied:

I suspect that there is more to the filtration than pore size. I would bet on a degree of surface adsorption being involved, stirring clay materials into water and allowing it to settle will precipitate a LOT of bugs.


Peter Macinnis asked:

Could you expand briefly on the McClellan reference?


Ray Stephens wrote:

Yes, I hadn't thought of that.
The baked clay filter shown on Catalyst last Thursday appeared to be only a ceramic filter, and the investigators made a point of showing variations in result by colony growth of bacteria on Petri dish agar, and how the pores left by baking used coffee granules were small enough to be the most efficient of the group of things chosen to add to the unbaked clay. I cannot recall all of the other 'disappear-kiln' materials, but I think grain husk was another one.

The point of the idea (for those who didn't see Catalyst) was to come up with an easy to make water filtration device for people with few (or none) of the resources we take for granted. Hence using bovine dung as the fire fuel, and the common orange-red, terracotta clay found just about everywhere.

A simple idea, clever bit of innovation, and scientific method used for qualitative and quantitative testing.

Always good to see.

Gerald Cairns observed:

I suspect that some organisms create biofilm colonies on the surfaces if not kept clean and in some cases these may even add to the filtration efficiency, BUT, the potential for pathogenics is a bit too real to abandon periodic sterilisation by fire.



Gerald Cairns replied:

I have been playing around with surface adsorption as an alternative to the use of topical antibiotics for antiscepcis. One combination of simple inorganics I have reported here previously as controlling and virtually eliminating otitis externa is highly effective. My hypothesis is that it causes agglutination of the microorganisms by binding to their surfaces and effectively interfering with normal functions of motility, communication etc.

I had suffered from a chronic sinusitis for years and got sick of being prescribed ABs to stick up my nose, something I cannot subscribe to as a safe use of ABs unless there is no alternative. Suffice it to say this has never worked effectively other than I guess to create more AB resistance. I thought about the above powder as being probably not suitable for a mucopolysaccharide environment such as the nose and sinuses because of the low levels of fats present. Using myself as the guinea pig thought it was worth a try and embarked on a course of applying the powder carefully to
the surfaces able to be reached with a cotton bud. As expected the immediate effect was not to cause a drying or immobilising effect on the surfaces but to disperse in the mucopolysaccharide secretions. However, despite the difference in action between the skin and the nasal mucosa the results were immediately effective with twice daily application effectively curing a 20 year old problem over a couple of months.

I have no doubt that the offending organisms are still present but no are longer dominant and I now am free of this complaint and its symptoms, without using ABs although some might like to argue that this is an AB in the broad sense of the definition. I have now been using this technique when necessary after minor periodic URT infections which I now very rarely get and can't remember when I last had a real cold it is years since that happened. I attribute this at least in part to the maintenance of a more suitable colony of microorganisms in the nasal passages and sinuses.

I also reported some months ago that I treated an severe wound to my hand caused by a hole saw which ripped open a large flap of skin and muscle at the base of my left thumb and extended up my wrist, using the same powder to limit the ingress of microorganisms from the surrounding skin. The powder also formed a concretion material with the exuding serum so forming an anti bacterial scab in addition to the zone of protection on the surrounding skin.

Initially this wound was cleaned up by my GP to remove pieces of plastic from it but I insisted on no stitches being used although he strongly pressured me to do so. The wound was treated with a spray and light water proof plaster to hold the flap in position but this failed to prevent infection. The powder controlled this infection at the surface very quickly while my immune system dealt with the subsurface infection and by forming the scab allowed normal healing. My GP warned that I may end up with a rather contorted protruding keloid, however this has not happened. About half the length of the scar is now invisible and the balance is a very fine scar that I doubt would be any larger than that which would have resulted if stitching had been used.

My purpose here is not to criticise current practise but to point to a potential alternative for wound management in the face of rising AB resistance. If my hypothesis is correct and the material is preventing the migration of infectious skin microorganisms into the wound without using ABs this is a valuable modality and one that seems to extend to mucous membranes also. If I can find the image of the wound that was taken at the time I will endeavour now to capture another in the healed state for comparison. I now intend refurbishing my Nikon microscope, which has been unused for years out of necessity imposed by others and will endeavour to visualise the effects of this powder in video and stills. Unfortunately our scarce resources are currently directed at another project and this may take time.

My comments about the effects of clay as a filter seem to me may well be related to the above.

An additional totally different application I have tried and seems to be working. This involves false alarms generated by our electronic security system caused by the geckos walking across the sensors - a real nuisance when you are not at base or in the middle of the night. Applying the powder around and on the sensor the geckos suddenly find their surface adhesion stops working and they fall off. :-) So far there have been no false alarms but we will need to observe this effect for a longer period to see if the initial results are maintained. This also suggests that such an approach may be useful on walls to limit colonisation by microorganisms, the powder applied is almost invisible and easily applied by brush.

Note I have been selective in the degree of disclosure of this information but it may stimulate others to thinking of such methods to prepare for the rising tide of AB resistance we face.

 In the thread "A Water Project Worth its Salt" on 12/7/2005, Toby Fiander wrote:

The NSW State Government intends to construct a water desalination plant at Kurnell. Predicatably, everyone hates the idea, if only because they did not think of it. The local Council apparently seriously advances the idea that this is a bad idea because no asked them, which is one better than not thinking of it, I suppose.

So why would Kurnell be a good site for a water desalination plant?

For starters, it is a location where there is heavy industry not far from the CBD of Sydney, and consequently, it already has a good connecction to the electricity grid, which it is going to need apparently to get that much salt out of that much water. The site is also more or less surrounded by seawater. It is already substantially degraded and, best of all, it is in an electorate whose political colour will probably not be influenced by the decision.

I notice that an eminent professor from UNSW wonders why in a temperate and well-watered area it is necessary to have a water-producing technology used by countries where there are really no other water resources. But this overlooks the fact that Sydney Water no longer has control of its catchments, and a desalination plant does not have a catchment. These are much more powerful and fundamental facts than mere climate.

Kurnell offers much more than just a location central to demand and already connected to the rest of the State by very thick wires - see below. It is a location more or less adjacent to the largest processing plant for petroleum in Australia, including its waste petroleum gases. It is near where a new off-shore natural gas pipeline could relatively easily make landfall. And, apart from the odd aerial navigation problem, it has some potential for a wind farm... all of which mean that the size of the thick wires may not need to increase. Consider for a moment the size of the electricity demand. If this desalination plant is going to produce 500ML/day, it will probably need to source about 200MW of electricity - and perhaps more - which is large enough to require amplification of the Transgrid electricity reticulation system back some distance. But it there is on-site electricity generation, there might need to be little or no amplification. It is the same argument I used to predict a Talawarra nuclear station, but that was before I realised that the resulting water would have to cross a bureaucratic boundary, which is, I later realised, against the laws of physics.

I rule out for the moment the potential for a nuclear reactor under the flight path at Kurnell, but it is certainly a consideration. After all, it shares the same Shire whingers as the Lucas Heights reactor site.

All in all, Kurnell seems a fine location to have a desert water plant - lots of sand (though less than there used to be, of course).



Toby Fiander replied:

I don't think there is a significant concentration of the water as it passes the semi-permeable membrane. There would be no point in concentrating the salt much, as practically there is an inexhaustible supply of seawater waiting to be pumped.  The only tricky bit is to retrieve the energy  imparted to the water after it passes the membrane.  I think it is this which is the "major advance" that the politicians keep referring to... there are articles, if you google, about using turbines (actually one of them refers to Pelton Wheels, which is reasonable given the high head) to retrieve the energy imparted as pressure to the water.

The minor increase in salt concentration probably means that, if 500ML/day is required, perhaps 10 000ML/day will need to be pumped from the sea to the processing plant.  There will be an optimal rate of concentration, controlled, I suppose, by the pressure of the water as it passes the membrane.  The design concentration will depends on the relative efficiencies of pumping from the sea and pumping to raise the pressure to pass the membrane, the efficiency of the membrane and probably a few other things.  I suppose there will be several membranes to be passed once the pressure has been raised, but I am speculating really.

If the intake rate is something like 10GL/day, then that is a lot of water to take from a relatively small area and there will, no doubt have to be
some attention to keeping fish and anything else swimming or floating in the vicinity out of the intake structure.  The drawings shown on TV seem to show a large metal housing shaped like a wheel with multiple entrances along its side.  If the discharge is as outlined above and the wheel is 2m high, for the velocity of the water at entry to be less than 1.0m/s, then the wheel would need to be about 20m in diameter... quite large.  It would need to be much larger if humans were permitted to be in the vicinity to keep the entrance velocities to safe values.

It would also need to be submerged all the time, which means in relatively deep water so it can be located above the shifting sand, and below the largest wave troughs... all in all, probably quite an interesting design exercise.

and:

Kirsten said:

Sounds like it could become one of those industrial parks
where by-products or waste from one industry is utilised by another
within the park.

If you look at the SMH map of the potential sites, you can't help thinking there must be a connection and using waste petroleum products somehow seems so logical.

Have a look here:
http://www.smh.com.au/media/2005/07/11/1120934186657.html

and/or here:
http://tinyurl.com/bj5ub

 yay, at last I have entered the 21stC.... :-)

Hmmm... must have missed it, myself.

and:

So, what date next month do they start construction?
(Joke Joyce)

Yeah... might be.

The official timetable is to go through the motions working up the planning context for about 6months and then engage some group in the following few months to, presumably, do both design and construct.  It might even be a Build-Own-Operate-&-Transfer arrangement.  These seem to be flavour of the month for water filtration plants and have some political risks, but not usually at the front end.

The plant needs to be constructed within the budget and completed on-time, too, because there is an election shortly after the target completion date. And there is no doubt whatever that water prices will need to rise to cover it, but I don't think that is necessarily a bad thing, nor is it likely Before the Election (BE) to any greater extent than is currently known.

However, all that said, if it rains significantly within the next 9 months, then the desalination plant is almost certain to be deferred.  Calculating the political risks is much harder than the physical risks, but as a general principle the odium of running out of water is much greater than the odium of spending $2b BE.



Peter Macinnis responded:

I cannot allow your diatribe to stand unchallenged.

In the first place, chocolate biscuits exist. This being so is sufficient to invalidate all of your arguments, but in view of your complete failure to allow for Coriolis forces, the anomalous property of water, which should be gaseous at room temperature, and the effect on its polarity of the rapidly inverting magnetic poles of the Earth (which entirely explains the rise in ocean levels) and the populations of magnetotactic bacteria currently swarming through the Bering Strait and heading for New Zealand, taken ipso facto (mutatis mutandis or vice versa as the case may be) the mutual annihilation of pasta and antepasta will see the chocolate biscuits engaging in coexistentialism.

QED and bar -- mine's a half, but go easy on the water if it has been inspected and passed by any list member,


Toby Fiander posted in the thread "Another Water Project Worth its Salt:

Fresh water is just the by product, there's
GOLD and URANIUM and PLATINUM
in sea water, you just need to process
enough of it (and stick the bill to the NSW
Taxpayer!) to have wealth beyond the
dreams of avarice.

I expect that Avarice is one of the ditzy dark-haired friends my daughter brings to dinner - I have never taken any notice of their names.  Actually,  for a time I thought they were all called Tracy-Leanne, although recently, I  noticed that one is called Chris and seems different from the others.  But it is a small point, or so I am told.

And - alas - I fear that, operated to produce Gold Uranium and Platinum, there would be a problem with precipitation in the membrane spaces of a  Reverse Osmosis desalination plant.   You could only do it for a short time and then you need to build a new plant.  I am sure Avarice does not dream of this - indeed, I wonder about such a description of her mental processes, but I digress.

Further, I am disappointed that demand management measures do not even rate a mention in the survey of preferred measures that the SMH is conducting.

The State Government has successfully introduced a system of mandating water and energy conservation of new developments using its BASIX certification program.  This will extend its reach soon into existing dwellings, including extensions and alterations and probably eventually a BASIX certificate of one sort or another will be required at the time of sale of houses.

It has been quite successful so far and there is an on-going program of monitoring its effect and changing the requirements, if that is found to be required.

BASIX has an objective tool for scoring developments which is operated from a central site.  You then get a certificate when a complying development has been entered and scored.  The certificate is then submitted with the Development Application to the Council who checks that the plans submitted are what is reflected in the certificate.  It is not foolproof, partly because fools are so inventive, but it is a great start.

The BASIX tool and contact details for the unit administering it are:

The BASIX team
Sustainability Unit
NSW Department of Infrastructure, Planning and Natural Resources
Ph: 1300 650 908
Fax: 02 9228 6544
email: basix@dipnr.nsw.gov.au
www.basix.nsw.gov.au

The website is worth a visit if only to see how the computer tool works.


Toby replied:


It is even worse inside Sydney Water, which values the water saved from finding and fixing leaks at 34c/kL, according to the leak detection people at a seminar about 18 months ago.

I notice recently that Sydney Water may have finally got the idea and has allocated a significant (though still insufficient) sum to renewal of pipes this year.

If there was serious volumetric charging for water - instead of the current Mickey Mouse arrangement, most of the people on this list would pay considerably less in their water bill.

Lest the reader considers that industry is somehow being left to use water as a "free-rider", many industries are having their sewerage charges ("trade waste" charges) upgraded.  The cost of disposal is now the most significant cost in the water cycle.  Some likely lads (yes, we were all blokes) put this forward as a model of how to charge residential customers at Byron Council some few years ago.  Volumetric charging for water AND sewerage has never caught on, but it seems to me to be entirely logical... still.  If you want to irrigate your lawn with the reticulated stuff, effectively you have to pay a penalty rate for doing so, unless you want to pay for your sewage to be metered or a supply agreement reached.

In any case, as we have discussed here previously, if the next unit of water augmentation is desalination, then the volumetric cost of water would should probably be about $2.00/kL or perhaps a little more.  Alternatively, if the next unit of water augmentation is roofwater tanks, then the cost of water should be about $3.50/kL.  The idea that ordinary folks should pay $1.30/kL after the drought has already emptied the dam and really bad buggers pay $1.80/kL for taking "too much" (as IPART has been saying) seems really silly to me.  The charging plan should be to impart that it is scarce and that Sydney-siders should stop using 20% more per head of population than anyone else in the country, simply because they arrogantly think they ought to be able to.  Putting the price of water up a little bit at a time from a fairly low base defeats the purpose and actually opens up the authority to the criticism that it is charging restrictions and charging a tax for supplying less water, which is poor economics and even worse marketing.

I notice that A/Prof. Greg Leslie thinks the cost of Sydney's water will have to rise to pay for desalination.  I should point out that Greg Leslie,
as a consultant, had a significant part of the responsibility for the NEWater project in Singapore:
http://www.pub.gov.sg/NEWater_files/forum/

So he speaks not entirely from an academic background but from experience in water scheme planning and implementation.  What Greg says about the price of water seems highly likely - we canvassed some figures here a little while ago that would indicate the same conclusion.  But the solution I think he favours, which involves indirect recycling probably through aquifers, would also be relatively expensive - in any case, it seems highly likely that in the next 20 years, all the alternatives canvassed to date for supply and demand mangement will have to be implemented.

Personally, I would have started a serious demand management program much earlier, including pricing for scarcity, used indirect recycling and then constructed Welcome Reef Dam next, with desalination still up the sleeve for an emergency.  It is what has been done in lots of other places, and it is what I have said for a long time.  But it is much easier with hindsight to see what might have been done, and the on-set of a drought has made it much harder to fudge the figures, as has often been done in the past.



David Maddern wrote:

With a new wave electricity pilot plant off Newcastle or is it Woolengong (I get them mixed up)
Then there's room off that area for some of those too, out of the sealanes and 'roads' of course

Steve van Zed wrote:

We must save on water. Why can't they make the fixed costs lower and up the varable costs.
As it stands now, saving on water does hardly make economic sense.
Water usage is only a small proporion of my bill


On 20/7/2005, Toby Fiander posted, in the thread " Cost of Desalination - second attempt"

OK... let's try again.  I posted this at about 5.00am this morning, and it seems to have been eaten by the system/software/gremlins.

The SMH reproduces some figures for the cost of the desalination plant in this article:
http://smh.com.au/news/environment/plant-threatens-to-double-sydney-water-bills/2005/07/19/1121538975644.html
or
http://tinyurl.com/e3cn8

The argument revolves around the contention that water will cost $2.44/kL, instead of $1/kL which is what it is now.  But calculated in the same way, a typical water user pays about $2/kL now.  It is just not charged that way at the moment.  There is a good argument that it should be, and immediately, not in little increments so that no one notices.

Because I am a frugal water user and most of the bill comes in fixed charges, I pay much more for water than $2/kL.  As a careful water user I am heavily penalised.

The SMH misunderstands how the difference between marginal pricing and average pricing... look, I could go into a detailed critique, but frankly, who cares?  It is clear sensible water charging policy is beyond the ability of the Government and its econocrats, let alone the understanding of the SMH.

On 8/2/2006, Ray Stephens posted in the thread "Best Layed [sic] Plans":

Apparently plans for a desalination plant servicing Sydney water has now been scrapped with the discovery of deep subterranean water supplies at least equal in volume to those presently existing in current supply.

Such a discovery would also, I imagine, send carbon dioxide sequestration plans back to the drawing board rather quickly, especially if deep waters are in motion like rivers below ground. On the other hand, it might depend where the aquifers are breached under pressure on the surface, and how much strata is shifted between this and that.

As a third topic within a single thread, how goes the process toward the synthetic $6M eye?

It was good to see a pair of Richmond Tigers making some real use of themselves for a boy about to have his eyes excised. I did not hear why in news passing, but empathy promotes the question. The computerisation required for interface between video camera (the prosthetics in glass as easy) and brain might still be beyond us I suspect.

To date, all I've heard in regard to the bionic eye is something the Japanese have devised which manages to restore a lesser degree of shape recognition (faces impossible as yet) and of night and daylight. Nothing as "Trekkie" as EMR resolution 'Raybans", unfortunately.


Toby Fiander answered:

Reading between the lines, the proposal could be to inject recycled water into the aquifer or for putting into the River and then supplying Windsor and Richmond from the increased flow.

Also, even allowing for Stuart White's penchant for looking optimistically at recycling, the proposal reuse another 70GL a year means there is a lot more water.  In other words, recycling is the nub of the proposal, not the groundwater itself.

Also, the stopgap measure (desalination) required to show that the State Government had a plan and Sydney would not run out of water at the same time as the election, is not required anymore.  It rained, just a little, but it rained and now the decision about desalination is not required until after the election.

I wonder if the Cabinet is going to lay an egg or just a new plan?


Ray Stephens added:

Dubai technology is it? Hmm, one wonders if the people of Dubai are into cost free provision of information and perhaps engineering assistance.

One also suspects that a money trail is difficult to find in the back scratching world of inter-governmental politics, and exactly what part of
negotiations we're not informed of.

Not that I care a great deal if the system works and is advantageous, but it still isn't solving the rude habit of using drinking water to flush sewerage whilst millions stand in queues in India for water which has no turds in it.

So, what date next month do they start construction?
(Joke Joyce)




On 12/6/2006, Toby Fiander wrote:

Here is an interesting article about a possible way forward with desalination:
http://www.technologyreview.com/read_article.aspx?id=16977&ch=nanotech

According to the article, carbon nanotubes do not behave as the equations for other materials with pores suggest.  There are apparent theoretical limits to how little energy is required for desalination, which we have discussed here previously.  But this article suggests that these limits do not apply to carbon nanotubes as the forces involved are of a different type.

I have not seen anything else about this elsewhere.  Perhaps others have.

And perhaps I will have to stop giving my father a hard time about the carbon filter he uses for his kitchen sink.


Gerald Cairns answered:

The power source is right where the water is, i.e. tidal and wave power - what better conjunction could we want?
and:

We use several methods of in-line filtration of the untreated river water. The most important is as always the macro particles of, biofilm, clay and pipe scale that block the fine filtration capacity of the carbon and ion exchange resins. Even with a 5 micron filter cloth as the first line of defence significant solids get through over time but at this pore size the cloth has to be washed regularly otherwise the back pressure is just too much for the pressure pump or even the mains - in winter a cold shower reminds us that the filter is blocked but in summer we have to be more vigilant.

Mixing solutions for our products we need to use the same approach and we get good service life out of carbon filters this way.

This is the sort of observation that I have referred to in other applications, some answers come unexpectedly from "left field" and we need to be alert to these possibilities. Oils ain't always oils despite similarities!


Gerald Cairns responded:

I am in no position to research this so my response may be off target. I would have thought that tidal/wave energy could have been used to do pumping also but there are a LOT of variables unfortunately. I must have a quick look at the Snowy Scheme to see if is possible to get a comparison between the piped distances but I would have to agree that friction losses would be a significant barrier. Now this needs to be my next project, eliminating friction in piped fluids. :-)) OTOH I have enough windmills to tilt at, forgive the pun. Actually you have just given me a germ of an idea, some time when I get free of the multitude of bureaucratic procedures that plague me I might take a look at this - for now it is a secret.

Stop the World I wanna get off!!!