Difference between revisions of "Fundamental resources/Water"
| Line 5: | Line 5: | ||
The intelligent use of mankind's water resources is not just an environmental issue; it is a public health issue. Drinking contaminated water is one of the most common causes of cholera, typhoid, diarrhoea, hepatitis A, dysentery and river blindness. | The intelligent use of mankind's water resources is not just an environmental issue; it is a public health issue. Drinking contaminated water is one of the most common causes of cholera, typhoid, diarrhoea, hepatitis A, dysentery and river blindness. | ||
| − | + | Suspended particles can be removed from water by passing them through a [http://en.wikipedia.org/wiki/Slow_sand_filter slow sand filter] with layers of gravel and sand. This is within the reach of all the World's people, as it requires no input of energy and no technological sophistication. A slow sand filter makes water safer for drinking, but does not fully remove all microscopic pathogens. UV light can kill water-borne pathogens. As [[LEDs]] get cheaper and more energy-efficient, the use of UV-emitting LEDs to sterilize water becomes more and more attractive. It would be a relatively simple matter to fit homes with the means to catch rainwater, pass it through a slow sand filter and sterilize it with UV light. In many temperate and tropical climates, this would provide the inhabitants of the home with an abundance of water. This decentralization of water-production would eliminate the need for complicated municipal water-distribution systems and would make individuals more independent and resilient in the case of [[disasters]]. | |
Using composting toilets rather than flush toilets would save 26.7%[http://www.epa.gov/watersense/pubs/indoor.html] of water use in the home. Composting toilets can also be used as a source of fertilizer to grow food and electrodes could even harvest electricity from the bacteria they contain (see [[Fundamental resources/Energy|Energy]]) | Using composting toilets rather than flush toilets would save 26.7%[http://www.epa.gov/watersense/pubs/indoor.html] of water use in the home. Composting toilets can also be used as a source of fertilizer to grow food and electrodes could even harvest electricity from the bacteria they contain (see [[Fundamental resources/Energy|Energy]]) | ||
| Line 12: | Line 12: | ||
The [http://challenge.bfi.org/application_summary/385 Watermill] is an invention that condenses water from the air. This water is clean and ready to drink. | The [http://challenge.bfi.org/application_summary/385 Watermill] is an invention that condenses water from the air. This water is clean and ready to drink. | ||
| − | |||
| − | |||
| − | |||
| − | |||
Nanofilters are an effective way of filtering out both suspended particles (which cause unpleasant tastes, smells and discoloration) and pathogens. The Tata Swach is a device that uses nanofilters to give very pure water. It retails for only $21. However, like other filters, it eventually clogs with impurities. <br> Filters made of [[carbon nanotubes]], small enough to let water molecules pass though, while blocking salt particles, impurites and pathogens, have recently reduced the price of desalination of sea water by 75% [http://www.technologyreview.com/read_article.aspx?ch=nanotech&sc=&id=16977&pg=1]. As 97% of the world's water is in the oceans, and unsalted water is needed for most human purposes, a practical method of desalination is a huge key to making Spaceship Earth work for all its inhabitants. IBM are conducting research into nanofiltration-based desalination [http://www.inhabitat.com/2010/04/07/ibm-saudi-researchers-team-up-on-solar-powered-desalination-technology/]. Filtration using nanotubes that are too small to become clogged is being investigated [http://cleantechnica.com/2008/09/15/carbon-nanotubes-might-be-used-in-future-water-filters/]. | Nanofilters are an effective way of filtering out both suspended particles (which cause unpleasant tastes, smells and discoloration) and pathogens. The Tata Swach is a device that uses nanofilters to give very pure water. It retails for only $21. However, like other filters, it eventually clogs with impurities. <br> Filters made of [[carbon nanotubes]], small enough to let water molecules pass though, while blocking salt particles, impurites and pathogens, have recently reduced the price of desalination of sea water by 75% [http://www.technologyreview.com/read_article.aspx?ch=nanotech&sc=&id=16977&pg=1]. As 97% of the world's water is in the oceans, and unsalted water is needed for most human purposes, a practical method of desalination is a huge key to making Spaceship Earth work for all its inhabitants. IBM are conducting research into nanofiltration-based desalination [http://www.inhabitat.com/2010/04/07/ibm-saudi-researchers-team-up-on-solar-powered-desalination-technology/]. Filtration using nanotubes that are too small to become clogged is being investigated [http://cleantechnica.com/2008/09/15/carbon-nanotubes-might-be-used-in-future-water-filters/]. | ||
Revision as of 23:49, 3 May 2010
Water is life. To secure a high standard of living for all people, we must secure a renewable supply of water for drinking, cleaning, cooking, irrigation, heating and cooling.
In the USA in 2006, the average water use per person per day was 575 litres. Compare this with 149 litres in the UK and 4 litres in Mozambique. Peter Gleick has said that 50 litres of water is sufficient for a person[1], though this does not take into account non-residential uses of water.
The intelligent use of mankind's water resources is not just an environmental issue; it is a public health issue. Drinking contaminated water is one of the most common causes of cholera, typhoid, diarrhoea, hepatitis A, dysentery and river blindness.
Suspended particles can be removed from water by passing them through a slow sand filter with layers of gravel and sand. This is within the reach of all the World's people, as it requires no input of energy and no technological sophistication. A slow sand filter makes water safer for drinking, but does not fully remove all microscopic pathogens. UV light can kill water-borne pathogens. As LEDs get cheaper and more energy-efficient, the use of UV-emitting LEDs to sterilize water becomes more and more attractive. It would be a relatively simple matter to fit homes with the means to catch rainwater, pass it through a slow sand filter and sterilize it with UV light. In many temperate and tropical climates, this would provide the inhabitants of the home with an abundance of water. This decentralization of water-production would eliminate the need for complicated municipal water-distribution systems and would make individuals more independent and resilient in the case of disasters.
Using composting toilets rather than flush toilets would save 26.7%[2] of water use in the home. Composting toilets can also be used as a source of fertilizer to grow food and electrodes could even harvest electricity from the bacteria they contain (see Energy)
Passive means of cooling and heating building would also lighten the demand on our water supplies.
The Watermill is an invention that condenses water from the air. This water is clean and ready to drink.
Nanofilters are an effective way of filtering out both suspended particles (which cause unpleasant tastes, smells and discoloration) and pathogens. The Tata Swach is a device that uses nanofilters to give very pure water. It retails for only $21. However, like other filters, it eventually clogs with impurities.
Filters made of carbon nanotubes, small enough to let water molecules pass though, while blocking salt particles, impurites and pathogens, have recently reduced the price of desalination of sea water by 75% [3]. As 97% of the world's water is in the oceans, and unsalted water is needed for most human purposes, a practical method of desalination is a huge key to making Spaceship Earth work for all its inhabitants. IBM are conducting research into nanofiltration-based desalination [4]. Filtration using nanotubes that are too small to become clogged is being investigated [5].
