Ozone application--pharmaceutical industry

Hospitals are generally divided into two categories: general hospitals and infectious disease hospitals. Hospital sewage has similar types and concentrations of pollutants to urban manure sewage, but it is not completely consistent. Because in addition to general pollutants, hospital sewage also contains some special pollutants, such as drugs, disinfectants, diagnostics, detergents and so on.

Hospital sewage mainly comes from various wards, especially sewage from various infectious wards, operating rooms and laundry rooms. In addition to a large number of pathogenic microorganisms, parasitic eggs such as mites eggs and various viruses such as hepatitis virus, tuberculosis and dysentery In addition, it also contains a large amount of pollutants, of which organic matter accounts for about 60% of the total amount of pollution, and insoluble matter accounts for about 40% of the total. When a large amount of incompatible substances such as muscle tissue are precipitated, a worm having a large specific gravity, an egg thereof, a large amount of bacteria, and the like are precipitated together in the sludge.

In recent years, radioisotopes have been widely used in medical treatments. These medical devices are usually rinsed with water, and therefore, the flushing water contains radioisotopes.

In addition, some hospitals also have an affiliated pharmaceutical factory, which contains harmful substances such as acid and alkali in the drainage. It can be seen that hospital sewage must be disinfected and decontaminated before being discharged into rivers.

Second, the process selection

The treatment method and the process flow are determined according to the treatment object, and the treatment object includes suspended matter, floating matter, organic matter, radioisotope, pathogen, virus, acid and alkali, and the like. Among them, the pathogen is the most harmful, and it is described as follows.

( 1 ) Suspended matter and floating matter
Septic tanks are generally installed at the exit of the ward. After the sewage enters the septic tank, the pollutants with a large specific gravity are precipitated and separated in the pool, and are fermented and digested. In the process of sedimentation, some virus pathogens are also deposited, so the sludge should be treated accordingly. The septic tank effluent will still carry a part of floating matter and mechanical impurities into the disinfection tank, which will affect the bactericidal effect of the disinfectant. Therefore, the sewage should be fully precipitated and simply filtered before entering the disinfection tank.

( 2 ) Organic pollutants
The organic matter of hospital sewage is generally smaller than that of urban sewage, and BOD5 is more than 100 mg/L. The water itself can be digested by its self-purification ability. However, if it is directly discharged into the surface waters, scenic areas, etc., which are required to be high, the organic matter is treated, and biological treatment is generally used.

( 3 ) Radioisotopes
Due to the spontaneous transformation of the nucleus to produce radiation, its presence makes the sewage radioactively contaminated and cannot artificially change the strength and performance of the radioactive material in the sewage. Therefore, only dilution or concentration should be used to reduce or avoid the hazard. For this kind of sewage, the treatment method can be determined according to the type and half-life of the radioactive substance. For elements with short half-lives, they are treated by storage or by dilution; for radioactive materials with long half-life, they can be physically, chemically or biologically treated and separated from the sewage. According to the survey, the radioisotopes currently used in general hospitals are all with a short half-life, and the amount of sewage is small, so it is usually treated by storage.

( 4 ) Parasites
The parasite eggs are derived from the feces and have a larger specific gravity than the fecal sewage (about 1.02-1.04), so they can be separated from the sewage by sedimentation. Ascaris eggs are generally used as the standard of death for parasites, that is, when the eggs of the mites die, they are considered to have died. Ascaris eggs can live for 1-5 years, but in the fermentation environment, the life cycle is greatly shortened. In the accumulated feces, you can live for 7 days in the summer and 21 days in the winter. Often used in septic tanks, the sludge clearing cycle is more than three months, and the parasite eggs can be completely precipitated in the pool and killed in the fermentation environment.

( 5 ) virus
Viruses are objects that are much smaller than bacteria. They do not have a complete cellular structure and must survive in certain living cells. 80% of human infectious diseases are caused by viruses. The virus is generally resistant to cold and heat (but the hepatitis virus has some resistance to heat, dryness and freezing, such as hepatitis A heat-resistant 56 ° C, more than 1 hour; B-type heat resistant 60 ° C, more than 4 hours), but All viruses are sensitive to high temperature boiling and strong oxidants, so a certain concentration of chlorine can be added to inactivate it.

( 6 ) Infectious bacteria
There are many types of infectious bacteria, but the law of their activities is similar. They generally live within the range of pH 5-9.6. When the pH exceeds this range, the bacteria will die. It can live for more than a month in clean water, but it takes less time to live in fecal sewage. This is because: a. The fecal sewage contains ammonia decomposed by itself, which can act as a bactericidal effect; b. Decomposition of the stool can also produce certain sterilizing hormones to inactivate the bacteria. In addition, most of the bacteria (except for tetanus are anaerobic bacteria) are aerobic. Using this feature, such as sealing the pool, on the one hand, due to the decomposition of organic matter, a large amount of oxygen, on the other hand, due to the difficulty of sealing the oxygen in the pool, the dissolved oxygen in the sewage is reduced, causing the aerobic bacteria to eliminate itself under the lack of oxygen.

In addition, heavy metals such as chromium and mercury exist in the laboratory and laboratory, and can be removed by chemical methods.

In summary, hospital sewage is an extremely complex system, so it is difficult to achieve satisfactory results using conventional treatment methods.

The recently developed ozone water treatment technology has been widely used in hospital sewage treatment projects and has received excellent results. Because ozone has stronger oxidation capacity than chlorine, bleaching powder and chlorine dioxide, it can be 600 times faster than chlorine. - 3000 times the speed to kill all bacteria, viruses, etc., which can not be completely killed by chlorine; some heavy metal ions such as Pb, Hg, etc. can be oxidized and precipitated for separation purposes; in addition, ozone can also reduce biochemical oxygen demand (BOD) and Chemical oxygen demand (COD), removal of nitrite and decolorization, deodorization, etc. The hospital sewage treated by this can greatly improve the discharge standard and can even be returned as non-potable water.

Third, the process flow profile

The entire process can be processed in two stages, as shown.
A. Primary treatment