Safe Water for a Thirsty World



Treatment Methods

UV Radiation:

Description

Use UV radiation lamp in water container.

Advantages

  • Simple to set-up and use.
  • Effective for inactivating microbes in drinking water.

Disadvantages

  • High cost at household level
  • Does not provide a chemical disinfectant residual to protect the water from recontamination or microbial regrowth after treatment.
  • Requires a reliable and affordable electrical source.
  • UV lamps require periodic cleaning.
  • Turbidity reduces effectiveness.

Boiling

Description

Boiling water with fuel

Advantages

  • Simple to perform.
  • Effective for inactivating microbes in drinking water

Disadvantages

  • Consumption of energy. Availability and cost may be issues.
  • Does not provide a chemical disinfectant residual to protect the water from recontamination or microbial regrowth after treatment.

Solar/Thermal Treatment (i.e. SODIS)

Description

  • Treat water by heating it to temperatures of at least 55û C in transparent bottles (plastic beverage bottles) exposed to sunlight for several hours
  • One side of the bottle is painted black
  • Exposure to sunlight for about 5 hours

Advantages

  • Effective for inactivating microbes in drinking water by pasteurization.
  • Simple to set-up and use.

Disadvantages

  • Not scalable - only small amounts of water can be treated at one time.
  • Requires ample sunlight.
  • Need to achieve sufficient temperatures.
  • Does not provide a chemical disinfectant residual to protect the water from recontamination or microbial regrowth after treatment.
  • Requires clear beverage bottles
  • Requires filtration to reduce turbidity.

Three (3) Pot Method

Advantages

  • Easy to set-up and use.

Chlorine

Description

Treat the water with a form of Chlorine

Advantages

  • Easy to use.
  • Most widely used disinfectant worldwide.
  • Proven technology.
  • Can be generated on-site by electrolysis of NaCl with the New Life International water purifier.
  • Provides residual protection from recontamination.

Disadvantages

  • Need proper dosage of chlorine to disinfect water.

Household Bleach

Description

Chloride of lime; a mixture of calcium hydroxide, calcium chloride and calcium hypochlorite.

Disadvantages

  • May contain other chemicals such as detergents, fragrances, etc.
  • Looses effectiveness with time.
  • Leaches chemicals from storage bottles.
  • Not as effective as Chlorine gas.

Ozone

Advantages

  • Very effective for inactivating microbes.

Disadvantages

  • Does not provide a chemical disinfectant residual to protect the water from recontamination or microbial regrowth after treatment.
  • Needs to be produced near the water source.
  • Difficult to produce.

Iodine

Advantages

  • Easy to use
  • Effective for inactivating microbes

Disadvantages

  • Expensive
  • Limited availability
  • Risk of iodine leaching into water.
  • Not suitable for on-going use.

Reverse Osmosis

Advantages

  • Effective against microbes
  • Reduces chemical contaminants

Disadvantages

  • Requires extensive pre-filtering
  • Large portion of the water is “rejected” and discarded
  • High cost
  • Does not provide a chemical disinfectant residual to protect the water from recontamination or microbial regrowth after treatment.

Sand Filtration

Description

Filter water by pouring it over a layer(s) of sand.

Advantages

  • Low to Moderately effective - especially against larger microbes
  • Reduces turbidity in the water

Disadvantages

  • Not effective against small microbes or viruses.
  • Inconsistent user application - requires maintenance.
  • Does not provide a chemical disinfectant residual to protect the water from recontamination or microbial regrowth after treatment.