Ultraviolet light produced by a germicidal lamp
inside a treatment chamber. During the past 6
years, graduates students have been designing and
testing a low-cost ultraviolet water disinfection
device specifically for peri-urban and rural areas
in poor countries, called the UV-Tube project.
Amount of Water Treated
Low pressure mercy arc UV lamp can treat 1 or more
liters per minute.
UV lamps have been shown to kill 99.9 percent of
vegetative bacteria, enteric viruses, and bacterial
spores. Removal rates for UV lamps are lowered by
the presence of organic matter, iron, sulfites,
nitrites, and turbidity because these particles
absorb UV radiation and shield microbes from being
hit with UV rays. UV radiation does not treat
chemical contamination or turbidity.
Ease of Use
UV lamp need to be cleaned regularly and handled
with care because of their mercury content.
UV lamp costs include the actual unit, electricity,
and replacement bulbs, which are typically needed
once a year. A small batch UV lamp system used at
the community level and all related expenses
typically cost less than US$1 per household per
year. When used at the household-level, UV lamps
and related expenses average US$10 to $100 a year.