.

Solar disinfection of water is the use of solar radiation to eliminate or reduce the microbial load in water sample,
producing disease-free water. Samples of water were collected from Kogi State University, Anyigba, Nigeria
and analysed for the presence of coliform bacteria. Coliform bacteria like Escherichia coli and Klebsiella
pneumoniae were isolated from the water. Disinfection of the water sample was done by subjecting the water
samples contained in plastic polyethylene tetrachloride (PET) bottles to ultraviolet (UV) radiation from the sun
at temperatures of about 45OC and for six hours. The two coliform organisms isolated from the water samples;
Escherichia coli and Klebsiella pneumoniae, show significant sensitivity for the solar disinfection (SODIS)
method. However terminal disinfection was achieved for K. pneumoniae and about 91 % reduction was
achieved for E. coli. Temperature readings determined before and after disinfection are 25OC and 45OC
respectively while pH readings was 7.8 before and after disinfection. This work shows that population of
bacteria in water samples especially coliforms which are the index of population could be drastically reduced
when subjected to solar disinfection method.
Key words: Disinfection, Solar radiation, Coliforms, Water sample.