When transmitted into water, UV radiation is absorbed by the DNA of pathogens. These UV rays
alter the DNA of these pathogens in such a way that they lose the ability to reproduce, multiply and
infect. Thus, they are essentially killed and cannot cause infection. This process of DNA
modification is known as inactivation.
Ultra Violet (UV) rays are high energy rays a wavelength shorter than that of visible light. They
are called ultraviolet because they are just beyond violet light in the spectrum. Technically,
ultraviolet light is defined as any wavelength of light which is shorter than 400 nanometer.
UV Process
700
400
Wavelength(nm)
UVB
280-315
UVA
315-400
UVC
200-280
X-Rays
Ultraviolet
Visible
Infrared
Microwave Radio
Ultra Filtration is a separation process that uses membranes with a pore size of 0.1 microns.
The UF membrane has the capacity to reduce colloidal material including bacteria and cysts
from drinking water. Low applied pressure is therefore sufficient to achieve high flux rates from
an Ultra Filtration Membrane.
UF Process
3
4
Water Flow Diagram
