These are mechanical units that continually add chlorine to the water storage tank. The tank allows the chlorine enough contact time to kill bacteria. Chlorinators need to be checked often to make sure the right amount of chlorine is being added to the water.
Ultra Violet Light Sterilization (UV Filters)
Water is passed through an ultra-violet light source to kill harmful bacteria. Water must be very clear for the treatment to work properly; water may need to be filtered prior to treatment. Drinking water should be refrigerated after treatment. The light must be replaced on a regular basis.
Water is boiled in one compartment, then condensed and collected in another compartment. Water should be filtered before treatment and refrigerated thereafter. Some organic and inorganic chemicals are also removed.
These are mechanical units that add small amounts of ozone to the water to kill most bacteria. Drinking water should be refrigerated after it is treated.