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Cross-section through a concrete biosand filter

LifeStraw® is a portable simple filtration device, which measures around 25 cm long and 29 mm in diameter, and filters up to 700 litres of water.

LifeStraw® contains a specially developed halogenated resin that kills bacteria and viruses on contact; a special chamber further increases the exposure of micro-organisms to the halogenated resin, thereby enhancing the killing effect. Micro-filters are used to remove all particles down to 15 microns. Granular activated carbon (silver-impregnated) adsorbs residual iodine thereby improving the taste of water.

It filters up to 700 litres of water and effectively removes most of the micro organisms responsible for causing waterborne diseases.

Advantages Disadvantages/limitations
- Does not require electricity

- Does not require repair or spare parts
- Can be carried around for easy access to safe and clean water
- Easy to mass-distribute in areas where drinking water is contaminated
- Easy to clean pre-filter as well as purifier cartridge

- Not a good development tool as it lacks sustainability

- Should not be shared
- Cannot be used by children


History and social context

Suitable conditions

The lifestraw can only be used for low turbid water. The released amount of iodine in water treated from LifeStraw® is not normally damaging to human health. However, people with thyroid problems or allergic reaction to iodine must seek medical advice before using this tool

A model applicable at a family level does exist.


Highly effective for: Somewhat effective for: Not effective for:
- Bacteria

- Viruses

- High turbidity

- Dissolved Chemicals
- parasites Giardia

Treatment process:
particle removal and disinfection
Inlet water criteria:
Contaminated fresh water


Technical specification

Operation

Place LifeStraw® in water and sip through the mouthpiece. Regularly blow through the LifeStraw® after drinking to keep the filters clean and to prevent them from clogging. To clean, wipe your LifeStraw® with a soft cloth

Treatment Efficiency

The University of North Carolina evaluated the performance of LifeStraw® personal water filter with regard to reduction of bacteria and viruses, level of iodine release and silver concentration in the filtered water. LifeStraw®:

  • removes 99,9999% of waterborne bacteria
  • removes more than 98% of waterborne viruses
  • removes particles down to 15 microns

Maintenance

The filterpen is quite sensitive to shocks, so avoid dropping or collisions. However, as far as proper maintenance is conducted, no real damage should occur.

Manufacturing

Vestergaard SA Tested by the University of North Carolina. LifeStraw® can be donated through various non profit organisations.


Estimated Lifespan

LifeStraw® filters up to 700 litres of water. If we assume that the daily water consumption of a person is 2 litres, then the life span is nearly 1 year.

Shelf-life is 2 years at 25°C or 1 year at 30°C.

Cost

Capital cost Operating cost Replacement cost Estimated 5 year cost Cost / metre cubed treated
US$4 = €2,85 US$ 0 US$ 0 US$ 12-30 US$5,71 = €4,08

Country experiences

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