Disinfection

Bacteria and microorganisms in the water are not completely eliminated in full at all even after the process of precipitation and filtration. To assure perfectly safe drinking water, therefore, further process of disinfection is absolutely indispensable. In most cases at present, we adopt chlorine or hypochlorite as the means for disinfection. In the United States and European nations, they adopt ozone for disinfection instead.

Under the standards for drinking water prevalent in Taiwan, a certain amount of residual chlorine should be maintained in the water distribution networks where ozone cannot be maintained in the residual amount. Under the standards for establishment, chlorine should be adopted for disinfection for tap water. At present in Taiwan, all water purification plants adopt chlorination for disinfection and all disinfection methods except chlorine have not been approved. Chlorine possesses such advantages including that it has complete disinfection effect, it be used for disinfection of various amounts of water and that the residual chlorine in the water still presents a disinfection effect.

At present, Chlorine is the most widely used disinfectant. Chlorine is known for its striking advantages including notably low dosage, inexpensive, capable of killing bacteria, viruses and amoeba in the water. Normally, chlorine, sodium hypochlorite or calcium hypochlorite are added to the water for disinfection purposes.