At present, most water plants in China use liquid chlorine to disinfect water. During the disinfection process, liquid chlorine interacts with humus and other organic substances present in the water to produce organic halides such as chloroform. The US Environmental Protection Agency has pointed out that organic halogenated hydrocarbons are common in drinking water disinfected with liquid chlorine, and chloroform, bromoform, monobromomethylene chloride, and dibromomonochloromethane are the most abundant.

     The sanitation and safety of drinking water are directly related to human life and health. At present, although many people start to drink pure water and mineral water, the vast majority of Chinese people still drink tap water treated with natural water bodies through conventional treatment processes. Due to the increasingly serious pollution of natural water bodies, tap water is still disinfected with liquid chlorine, which will cause hidden dangers in water.

     Scientists have proved through a large number of animal experiments that chloroform is a carcinogen. Monobromomethylene chloride and dibromomonochloromethane have poisoning effects on the liver and kidneys. Their harm to the human body has been recognized by the world. Scholars from the United States, Canada, Japan and other countries have found that in regions with high levels of organic halogenated hydrocarbons, the incidence of gastric cancer, liver cancer and bladder cancer has increased significantly. Professor Yang Beichang of Chenggong University in Taiwan studied the relationship between drinking water disinfection with liquid chlorine and the risk of cancer in 14 townships in Taiwan, and compared it with 13 townships that were not disinfected with liquid chlorine. It was found that between 1981 and 1991, The mortality of colon, bladder, lung and kidney cancer in towns and villages disinfected with liquid chlorine was significantly higher than that in towns and villages without liquid chlorine.

    China has stipulated that the content of chloroform in drinking water shall not exceed 60 micrograms / liter, and the United States is more stringent. The total content of chloroform, monobromochloromethane and dibromomonochloromethane shall not exceed 80 micrograms / liter. However, when liquid chlorine is used for disinfection of drinking water, the chloroform content exceeds the standard. Not long ago, the SARS epidemic broke out, and some TV stations also specifically reported that many water plants are increasing the amount of disinfectants to ensure 'safety', but they have increased the probability of the above carcinogens.

     Chlorine dioxide generator

    Due to the unsafe hidden danger of liquid chlorine disinfection of drinking water, the World Health Organization and the World Food Organization have recommended to the world A1 grade broad-spectrum, safe and efficient disinfectant-chlorine dioxide. At present, most water plants in European countries, the United States and Canada have used the disinfectant. The US Environmental Protection Agency uses chlorine dioxide as the preferred disinfectant to replace liquid chlorine, and has made specific regulations for the use of chlorine dioxide in disinfecting drinking water. Italy not only uses chlorine dioxide to treat drinking water, but also uses it to control biological pollution in water and cooling water systems such as steel mills, power plants, pulp mills and petrochemical plants