How small and beautiful new technologies are helping to provide clean drinking water

In areas which are dry and therefore short on safe water sources, people must risk using contaminated drinking water in order to survive - a risk that can be life-threatening, due to diseases such as cholera and dysentery, or poisons such as arsenic and mercury.

Practical Action have been using nanotechnology - materials and systems on the scale of less than 100 nanomenters - to purify drinking water.

A cost-effective and efficient solution

A major challenge in working with nanotechnology is to focus attention on the real human needs of people. The need for clean drinking water is a well-documented need that still affects over a billion people in the world. There are already many technologies available that can help remove biological and other contaminants from water, yet nanotechnologies may provide more cost-effective or efficient solutions.

  • Nanosponge for rainwater harvesting - A combination of polymers and glass nanoparticles that can be printed onto surfaces like fabrics to soak up water. The nanosponge is much more efficient than traditional mist-catching nets
  • Nanorust to remove arsenic - Magnetic nanoparticles of iron oxide suspended in water bind arsenic, which is then removed with a magnet
  • Desalination membrane - A combination of polymers and nanoparticles that draws in water ions and repels dissolved salts. This membrane enables desalination with lower energy costs than reverse osmosis
  • Nanofiltration membrane - Membrane made up of polymers with a pore size ranging from 0.1 to 10nm. Using this membrane requires less energy than reverse osmosis
  • Nanomesh waterstick - A straw-like filtration device that uses carbon nanotubes placed on a flexible, porous, material. The waterstick cleans as you drink
  • World filter - Filter using a nanofibre layer, made up of polymers, resins, ceramic and other materials, that removes contaminants. Designed specifically for household or community-level use in developing countries. The filters are effective, easy to use and require no maintenance
  • Pesticide filter - Filter using nanosilver to adsorb and then degrade three pesticides commonly found in Indian water supplies. This pesticide filter could provide a typical Indian household with 6000 litres of clean water over one year


Victor is 41 and lives in the Pumanota community. He and his wife have five children; three of them study in the city of Sicuani, since the community only has one educational centre located very far from their home which requires a four-hour walk, and the studies offered are only up to fourth grade primary school. He only lives with his younger children; he and his wife take turns to see their children in Sicuani. 

They raise and breed alpacas and llamas for a living; he herds them every day, cures them when they are ill, his wife makes the meals and later takes them to graze while he waters the pasture lands. 

Victor says that the high-Andean communities had not received support in any form before the arrival of Practical Action with an emergency project for the extreme cold in 2004. Since then Practical Action have carried out the Allimpaq and Alturas Canchis projects, which helped them improve alpaca breeding and the cultivation of improved pastures.

He is now working with the Allimpaq project, which he is very grateful for since for the first time his home has basic services, they did not have basic services before and had always lived in the same manner as their parents. Now, Victor says, they have an ecologic toilet and no longer contaminate the environment, his children live as they would in the city, they have an improved and smoke free kitchen - his wife used to complain greatly about the smoke because her chest hurt, and now they have come to the conclusion that they also save on fuel; they used to drink dirty water from the stream before.

There was also faecal matter from the livestock and garbage, but now they have a water catchment system, which leads to the pond, and since it is water from an irrigation ditch, the project has installed a Nanotechnology system. This system purifies the water and kills bacteria, so now his family consumes purified water. The engineers constantly analyse the water in order to learn about the treatment’s efficiency.

They own an 80Wp solar panel, which provides light during the night; they no longer use the kerosene lamp which gave his mother headaches, now she does not complain at all. The panel also allows them to hear the radio and a music system. The most important thing for him is that he no longer buys batteries and can recharge batteries for his neighbours, who pay him by working on his land, now he has a solar lamp that allows him to watch his animals during the night and keep the fox away from taking his alpaca younglings.

He also has wells used to separate the organic and inorganic waste, he feels that his home is cleaner and neater; he knows how to dispose of his the plastic bottles, batteries, cans, veterinary medicine bottles, bones, etc. Having these services is something new for him and he says: 

“For me, having and learning about these services is a godsend, because I did not know of the projects planned by Practical Action, one day during a meeting called by Practical Action, I participated and approached the Allimpaq engineers to talk”.

His family’s health has been an aspect that has improved greatly, he has perceived that the kitchen is smoke free and his children stopped coughing and complaining about the smoke; they also do not use kerosene lamps, or candles. His wife does not complain of headaches; they no longer take care of their biologic needs in open fields or construction sites of old houses, now they feel satisfied and content with the technologies in this area. 

Victor’s mother says: 

“Now we no longer bring the water from the stream, we have water in our backyard; I cannot believe how times have changed”.

There a collective willingness to pay for the electric service, if they get organized at the community level, but if that is not the case, he is also willing to maintain it privately, and if something needs to be repaired, Victor is also willing to pay for a technician. He says that he will not stop having light in his home because his family has become accustomed to having it. Additionally, now that he no longer buys batteries, kerosene and candles he has more money for his children’s education and has bought them new books. He used to buy 4 bottles of kerosene per month, which is S/. 12 soles, 4 pairs of batteries at S/. 8 soles, 6 candles at S/. 6 soles, spending a total of S/. 26 soles; with what he has saved he also buys more vegetables and, as he has mentioned it is all thanks to Practical Action’s Allimpaq project.

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Nanotechnologies for water and sanitation seminar 27 November 2007, Peru Dr Jorge Seminario powerpoint presentation English

Nanotechnologies for water and sanitation seminar 27 November 2007, Peru Dr Jorge Seminario powerpoint presentation English

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