There are two common methods for disinfection of hospital wastewater: chlorination and ozone. There are two types of methods for detoxifying and treating hospital wastewater: physical methods and chemical methods.

1 Chlorination treatment of hospital wastewater Chlorine, as a chemical agent for chlorination and disinfection, has been used for sewage treatment by the British Sewage Commission in the 19th century for more than 100 years. Chlorination method is divided into sodium hypochlorite method, liquid chlorine method and chlorine dioxide method according to the different dosage.

    (1) Sodium hypochlorite dosing method

 Sodium hypochlorite (NaClO) is one of the original disinfection methods. This method is widely used due to the characteristics of convenient raw material sources, stable and safe products, and convenient transportation. Sodium hypochlorite can be purchased on the market as a commodity, or it can be produced on the spot. At present, small-scale hospital wastewater treatment site production generally uses electrolytic salt method. However, the sodium hypochlorite has a weak disinfection ability, and it brings waste residue during the process, which is gradually being replaced by other products.

    (2) Liquid chlorine method

  Liquid chlorine disinfection is widely used in tap water and hospital sewage disinfection because of its strong disinfection ability and low price. Liquid chlorine has a high concentration of chlorine, with an effective chlorine content of more than 99%, which is 5-10 times higher than that of sodium hypochlorite solution. But chlorine is a yellow toxic gas with an irritating odor. It must have special storage equipment and chlorination equipment. At present, typical chlorination equipment includes manual timing open-type chlorination and automatic lifting chlorination. However, related data studies show that liquid chlorine (Cl2) will react with ammonia to produce monochloramine, dichloramine and trichloramine and consume liquid chlorine. It can also form carcinogenic trihalomethane (THM). Incompleteness, so liquid chlorine disinfection is limited.

    (3) Chlorine dioxide method

     The solubility of chlorine dioxide (ClO2) in water is five times that of chlorine, and its oxidizing ability is about 215 times that of chlorine. It is a strong oxidant. Is an internationally recognized high-efficiency disinfectant in chlorine disinfection. It can kill all microorganisms, including bacterial propagules, cell spores, fungi, mycobacteria and viruses. It can effectively destroy trace organic pollutants in water, such as benzoxanthraquinone, chloroform, carbon tetrachloride, phenol, chlorophenol, hydrogen sulfide, and organic sulfides. It can well oxidize some reduced metal ions in water such as Fe2 +, Mn2 +, Ni2 + and so on. The advantage of chlorine dioxide is that it does not produce divergent organic halides by reacting with humus and organic matter, does not generate and inhibit the formation of carcinogenic trihalomethanes, and does not react with ammonia and amino compounds