medical wastewater characteristics
Hospital wastewater containing pollutants, such as drugs, disinfectants, diagnosis of the agents, detergents, and a large number of pathogenic microorganisms, parasite eggs and a variety of viruses, such as Ascaris eggs, hepatitis virus, tuberculosis, and dysentery microorganisms in . In addition, features the isotope consulting room of the hospital sewage containing radium 226, phosphorus, gold 198, iodine 131 and other radioactive substances. Compared with the industrial wastewater and domestic sewage, it has a small amount of water pollution and strong features. Such as any of their emissions, is bound to pollute the water-borne diseases. 2, the traditional hospital sewage treatment
2.1 Biological Oxidation
Biological oxidation, also known as activated sludge process, a variety of sewage treatment is the most commonly used approach. Aeration, mechanical aeration of sewage in a large number of filamentous bacteria and fungi, such as the propagation of microorganisms, these organisms have the capacity of the adsorption and oxidation of sewage harmful substances, thereby reducing the COD and BOD of the sewage, the sewage to reach purification effect. Some sewage treatment plants and anaerobic and aerobic. Anaerobic process, anaerobic microbial reproduction, nitrification and adsorption of harmful substances. The disadvantage will produce large amounts of activated sludge, sludge treatment and to be lengthened processes to increase the cost of the project, and the secondary pollution caused by air in the aeration process. The examples of this. Commonly used in bio-oxidation with biological contact oxidation method, rotating biological contactors law, tower biofilter law, jet aeration and oxidation ditch method.
2.2 chemicals law
Chemicals law, is to put the right amount of sewage chemicals, harmful substances in the sewage oxidation, to achieve cohesion adsorption precipitation. This method is a traditional biochemical method after nearly three decades gradually developed the ① liquid chlorine, liquid chlorine, it disinfection capacity, cheap, widely used in water and hospital disinfection. But chlorine is yellow poisonous gas with a pungent odor, not anywhere preparation of chlorine, there must be dedicated for storage of equipment and chlorination equipment. Liquid chlorine dosing equipment, complex structure, susceptible to corrosion, greater risk, and thus restrict the use of too concentrated in the cities or population area. ② sodium hypochlorite solution and sodium hypochlorite is one of the most primitive method of disinfection. This method is convenient sources of raw materials, product stability, easy transportation, equipment investment, low running cost, easy management, safe, reliable, not disinfectant sludge is widely used. Sodium hypochlorite disinfection capacity is weak, the process to bring waste, and gradually substitute other products.
The ③ ozone Ozone is a strong oxidant, and add the appropriate amount of ozone in sewage microorganisms in water, as well as a variety of metal ion oxidation. Hospital sewage in this way is more thorough, less secondary pollution. The disadvantage is that the supporting equipment, one-time investment, equipment and maintenance of large power, an increase of perennial running costs. 3, a better approach 3.1 CASS to the process of biochemical treatment CASS pool through technological innovation, to optimize the design to make it smaller volume, better. This method is water, but not aeration, the high concentration of organic matter, showed a lack of oxygen and anaerobic conditions, inhibited the growth of aerobic bacteria, sludge control swell. The main reaction zone is divided into two parts of hypoxia and aerobic aeration, sedimentation, and write-water cycle. Precipitation stage is not the water, eliminating the hydraulic interference that may arise, the sludge characteristics and effluent quality. Very complex composition, containing a variety of bacteria, viruses, parasite eggs, and harmful substances, water quality and quantity changes in hospital effluent [2] has a stronger adaptability and better treatment effect, is an ideal hospital sewage biochemical treatment methods.
3.2 chlorine dioxide disinfection
Chlorine dioxide is an efficient, broad-spectrum, safe, fast, multi-function, duration, length, storage and easy-to-use disinfectant, the United Nations World Health Organization (WHO) as a safe disinfectant (A1) level U.S. Environmental Protection Agency (EPA) and the United States Food and Drug Administration (FDA) approved it can be used in hospitals, food processing and other departments.
Domestic and foreign production of the commodity chlorine dioxide products are mainly stabilized chlorine dioxide solution, but also a small part of the sustained-release groups like colloidal particles, microencapsulated powders and other solid chlorine dioxide products. In recent years, domestic sewage treatment industry is very popular chlorine dioxide, hospital sewage treatment, have a good effect.
