NOVELTY - A water treatment system (20) comprises: a container (50); a cover (48) removably coupled to the container; at least one UV germicidal light bulb fluidly coupled to the container, where the UV germicidal light bulb is disposed within the container when the cover is coupled to the container; and at least one electrical generator configured to couple with a bicycle frame (22), where the generator is electrically coupled to provide electrical power to the UV germicidal bulb.    USE - As water treatment system for purifying water (claimed).    ADVANTAGE - The portable mechanically powered water purification system is easy to use, low in cost, and is high in efficiency and durability. The system can be transported to the location it is needed making it easier for users to purify their water in a convenient place. Moreover, the system is able to treat sufficient water for a two people for an entire day in a short period of time.    DETAILED DESCRIPTION - INDEPENDENT CLAIMS are included for the following:    (1) a water treatment system powered by a bicycle comprising: a stand having at least one coupler configured to suspend a driven wheel of the bicycle to rotate freely; at least one generator removably coupled to the bicycle; a filtration system (44) disposed adjacent the stand, where the filtration system includes: a container fluidly coupled to the filter; and at least one UV light bulb electrically coupled to the generator, where the UV light bulb is disposed to emit ultraviolet light into water within the container; and    (2) purifying water involving: coupling a bicycle to a stand to allow a driven wheel to rotate freely; coupling a generator to the bicycle frame, where the generator is arranged to rotate in response to rotation of the driven wheel; providing a container with a cover, where the cover further has at least one UV germicidal light bulb operably coupled adjacent the filter; pedaling the bicycle for a predetermined amount of time; and powering the UV germicidal light bulb when the bicycle is pedaled.    DESCRIPTION OF DRAWING(S) - The figure shows a perspective view of a water treatment system.    Water purification system (20)    Bicycle (22)    Filtration system (44)    Cover (48)    container (50)