Comments on "Provide Access to Clean Water"

Water is being contaminated in developing countries in Central America and India. Drinking water/safe water is finishing in these countries.
is there a way we can get that water back and stop it from being dirty?

The water supply is a problem, I think they should try using electro-dialysis (reverse osmosis) or using salt water to power the energy for desalination.

Most of the papers and articles written on this serious issue with access of clean water, do not adress the core of the issue. They always choose to chase their tails. Science and Engineering are excellent dumb tool that can not fix todays problems. Under Developed or developing countries have their hands tied behined their back, you need to figure out why!!
Every thing cost money, their governments are not working for them.

I dont really care about the water supply, Africa can get their own

i think its your job as environmentalists to make our water safe! why not give classes on water purification that each home owner can do themselves ? we all know that soon our safe world as we know it now wont be so safe any longer !

It is nice to see some really creative ideas circulated by NAE. I know some people personally whose thinking is constrained neither by the second law of thermodynamics nor by rules of economics. Go get 'em.

For the rest of us, the dratted second law tells us that to get a ton of fresh water from a water source containing 3.2% salt, we need to expend 0.64 kWh no matter how we do it. That is the absolute minimum, which we cannot even be approached by any practical device. Engineering economics is less rigid, but experience teaches that expending energy to do work takes equipment, and it isn't even close to free.

Amazingly, the overall efficiency of real devices long ago passed through 10%, and it is rising slowly but inexorably.

When I was a wee lad, a very wise chemical engineer opined that getting food crops to grow in salty water looked to be an easier challenge than making irrigation water from the sea. I am now an old man. Alas, I'm still waiting.

There is plenty of fresh clean water in the world (mostly frozen). Access is the issue -- this can be solved with Evacuated Tube Transport (google it).

It is interesting that the discussions related to the limitations of our natural resources, including those pertaining to water, do not address the core issue which is that our exponentially increasing population will at some point exhaust our ability to sustain ourselves. Even if breakthroughs in desalination or water reuse occur we will soon have to face the fact that "built out" is a reality. What will we do then? What will be the political and societal consequences then? Has anyone looked to determine what a sustainable population is in the US? I know this is not a popular thing to do but considering that changes in climate are already pushing us to the limit it is a sorely needed research area.

I have a very successull water cleaning apparatus that will change the way water is cleaned, economivcally, perfect clean and the worst problemm that I have is getting some company to look at it. The majors are so tied up mentally and $$$ with RO etc that they want us to go away,I will demonstrate my 10,000 gallon per day unit any where any time to anyone willing to help us go forward

Rain water harvesting is the cheapest method be it through micro-watersheds or roof-top collection; suitable for rural areas like in India where 70 percent of population is located in 0.6 million villages. Any centralised treatment at village level will be difficult to maintain and operate. POU rather than POS is the best option for treatment;even the cheapest water treatment device is beyond the purse of the poor;solar water treatment raising the temperature to over 65 degrees to kill all pathogens by use of a bamboo basket covered with eating-plates coated with Aluminium foil [total cost rs.50 or one dollar] is the best option for POU; second best is making available Water purifier packets of iron sulphate and calcium chloride [a CDC and P&G innovation] in village shops at Rs.one per packet. The cost can be reduced by use of drumstick/strichnos potatorum for flocculation. The best place to treat water is at point of use and the best agent to do this is the mother.