Strong sunlight disinfects water by permanently de-activating bacteria, spores, moulds and viruses.
The mechanism of kill is well documented and unlike chemical disinfectants the organism is unable to develop any immune mechanisms. The mechanism of kill involves the absorption of photons of UV energy by the DNA, which fuses the DNA and prevents replication. These compounds are linked along the chain by sugar-phosphate components. The purine and pyrimidine combinations are called base pairs. The most effective wavelengths to achieve this effect are found between 263nm to 275nm, and the peak wavelength distribution is dependent on the target organism.