Desalination is also effective in removing other chemicals like fluoride, arsenic and iron. Disinfection is a way of ensuring that drinking water is free from pathogens. The effectiveness of chemical and solar disinfection, and to a lesser extent boiling, is reduced by the presence of organic matter and suspended solids. Disinfection by boiling. A typical recommendation for disinfecting water by boiling is to bring the water to a rolling boil for 10-12 minutes.
Chlorination is the most widely used method for disinfecting drinking water.
Iodine is another excellent chemical disinfectant that is sometimes used. Both chlorine and iodine must be added in sufficient quantities to destroy all pathogens but not so much that taste is adversely affected. Deciding on the right amount can be difficult because substances in the water will react with the disinfectant, and the strength of the disinfectant may decline with time depending on how it is stored. Solar disinfection uses solar radiation to inactivate and destroy pathogens present in water. Filtration includes mechanical straining, absorption and adsorption, and, particularly in slow sand filters, biochemical processes.