Chlorination method for disinfection of tap water in water plant

The chlorination method is used for the disinfection of tap water in the water plant. The main action substance used in the production process is chlorine gas. The tap water production of the water plant is divided into four stages: water intake, filtration, disinfection, water delivery, after the tap water enters the water plant, the first process is filtration, and Zhuganshan Water Plant uses polyaluminum chloride (plus SO42-) as a precipitant, The concentration of AlCl3 in the medicine pool is 6%, and the concentration in water is 2mg / L. Polyaluminum chloride can remove trihalomethane precursors in water and prevent the production of carcinogens.

The filtered water should be disinfected, and the disinfectant should be chlorine gas. Chlorine gas is easily soluble in water and combines with water to form hypochlorous acid and hydrochloric acid. Its main role in the entire disinfection process is hypochlorous acid. For the odor-causing inorganic substances, it can completely oxidize and disinfect it. For living natural substances such as algae and bacteria, it can penetrate the cell wall and oxidize its enzyme system (enzyme is a biological catalyst) to make it lose Activity, so that the life activities of bacteria are hindered and die. Hypochlorous acid itself is neutral, easily accessible to bacteria and shows good sterilization effect. Hypochlorite ion also has a certain disinfection effect, but it is negatively charged and difficult to access bacteria (bacteria is negatively charged), Therefore, its sterilization effect is much worse than hypochlorous acid, so the disinfection effect of chlorine gas is better than that of bleaching powder. When in use, the liquid chlorine is depressurized by the pressure reducing valve, and then enters the chlorine throwing machine and throws into the water. The water plant uses about 1.5 tons of chlorine gas every 10 days, and the water output reaches more than 1 million tons.