What a startup for a discussion.

I will start by saying more improved water treatment methods.

Yo pienso que un elemento fundamental para lograrlo es el establecimiento de precios o tarifas que reflejen los costos marginales de captar, almacenar y distribuir el agua para los usos agricola, industrial y del hogar

Maybe first educate our society to protect water by saving this ressource. Develop more biotechnologies to purify waste and contaminated water and use these waters for irrigation for example.

Indubitably, modern treatment methods of water aim to improve the quality of water to make it more acceptable for specific target uses including its use for drinking, industrial , irrigation, and recycling purposes among others. The final objective is to ensure that after use, water is being safely returned to the environment. The main reason is that contaminated water can ruin the environment , and without a healthy environment, sustainable economy would merely be a myth.

There are several overlapping issues here.

First, the cost of having clean water will increase. That will ultimately mean a greater investment in the infrastructure required to have clean water, and thus a greater investment in the education of the people to create and operate this infrastructure.

Second, the cost of using clean water will increase. Industrial processes that use water will be economically encouraged to find ways to not use clean water. Those that can't adapt will find they can't compete with those that can.

Third, and perhaps the most problematic, is that the reliance on technological investments will decrease resilience as efficiency is increased. At the same time as when uncertainty is increasing, and dependence (and thus sensitivity) is also increasing, we will find resilience to be decreasing. We would have to choose now to ensure that our engineering in the future is intentionally more resilient and capable of adaptive management. Hard to be proactive.

Mining fossil groundwater is a very short sighted approach - I think of lemmings, falling off a cliff. History has shown that extraction would be increasing at a reasonably consistent rate, until suddenly the supply is completely exhausted. Even if we saw it coming, we would be looking at ways of become more efficient, not finding ways not to need the fossil resource in the first place.

For any non-renewable resource, the community would have to decide how to wean themselves off of it. If, for example, they are annually using 2% of the proven reserves, then they must choose to decrease extraction by 2% per year. And simultaneously, find how to improve people's quality of life by at least as much as would come from that reduction in supply.

The talk of desalination is OMG dumb. It is far less energy and complexity to convert dirty water into clean water than to convert sea water into clean water - if there isn't enough water, then the community can't have population growth and degrowth is required. Residential development must be tied to a permanent supply of water that is not dependant on our current high-energy-intensity economy. World Peak Total Energy will be happening in about 45 years, and the infrastructure we are building today won't be able to be maintained as expected after that. Planning on business-as-usual means creating a future that is bankrupted when oil jumps to $200/bbl.

So:

Communities must be able to manage the critical resources they require to be able to say they are sustainable. In water-poor areas, water is a critical resource. They must show how they can meet their water needs from the land-mass they manage, or they must make arrangements with other communities to be able to co-manage a shared water supply. If a population change is required, that can't be on the basis of a 'highest bidder' relationship with a vendor-of-convenience. The relationship must be much more integral to the two communities.

They must find ways to keep their wastes as close to their original quality as possible, so that existing infrastructure will continue to be able to be used. Which generally means not using water as a waste carrier. If there is a waste product from an industrial process, it should be kept onsite, or not used in a water-poor area. Residential sewage should be regarded as a source of water and fertilizer, and shouldn't be allowed to be polluted by other waste streams. If this means 2 sewers (one residential, and one industrial), then so be it.

Most water used doesn't need to be potable. There is no reason that one can't have a black water system, a grey water system, a white water system (filtered grey water), and a blue water system (treated white water), with the blue water amounting to a few liters per day per person, the white water about 10x as much. Grey water, for example, can be used for fighting fires. White water for running washing machines and toilets. Etc.

There's more that can be done, but that's a good start.

Good discussion

Dear Friends and Colleagues of RG

What technologies of water purification and seawater desalination should be developed?

There is less and less water on Earth. In connection with the development of industry, increasing water consumption in households, exploitation of deep water, increasing pollution of rivers, ponds, lakes and seas as well as the progressing global warming process, clean water resources are falling.

In connection with the growing consumption of water and falling resources, an important question arises: What technologies of water purification and desalination of sea water should be developed?

Best wishes

One of these methods is the use of seawater distillation technology using solar energy

Interesting discussion

Darius;

No, there is not a reduction of water on earth. That's a finite total that is effectively unchanging (on a human time scale). What is changing is where the water is, and where we expect it to be. We are mining aquifers, diverting rivers, contaminating supplies, and populating based on a declining resource. At some point, there will be a reckoning, and it will be pretty rough for a lot of people.

There is less drinking water per capita for the vast majority of the planet. Within my lifetime, we are going to see a peak in fossil carbon, and I may just live to see a peak in total energy output. So making drinking and agricultural water with fossil carbon is really dumb, and making drinking and agricultural water with solar just delays the crash. It is possible the water crash can be put off indefinitely for a large proportion of the population, but I don't think for everyone.

So, for the purposes of delaying the crash, solar desalination is mandatory - it can be done at the interface between desert and ocean at relatively low capital investment. But we have to find ways to grow food that requires less desalinated water - either grow food in salt water, or find a way to build greenhouses that can trap water inside.

Valuable information....

In recent years, water deprivation has also been more and more common in many countries. Much of the data from climate change prediction analyzes suggests that these problems are related to drought being a derivative of the global warming process and these problems may increase in the years to come.

The quantity and quality of water are major future global concerns with more and more countries recording water deficit.

Potable waters used in many countries across the globe are far below standards of 'clean water' category. While there need for RRR (Recycle, Recharge and Reuse) of water, it is highly desired to develop indigenous low-cost technologies for providing clean water to mitigate the local demands. This issue becomes utmost important as many countries are not even able to set up or even afford 'basic water treatment' techniques. The future of a large fraction of humanity is bleak without 'adequately safe drinking water supply'. Let us all realise this grave situation with availability of limited water quantity per capita in future decade.

We should develop and low cost technology for geting clean water. It is a world wide concern

Low cost clean water technologies used by our grand / great-grand parents need to be revived.

These were often used in our rural areas and perhaps better than modern RO's.