Preface. Water, water, water all around... Our body consists of 70-75% water, the jelly-like formation - our brains - consists of it, excuse me, 90%, and our blood - 95%! Deprive a person of water - and what will happen to him? Even relatively small, five to ten percent, dehydration

Sterilization can be carried out either by ozonation or irradiation with ultraviolet light.

Ozone is the strongest oxidizing agent. Its molecule is not stable and breaks down into individual atoms that tend to undergo oxidation reactions. Ozone increases the intensity of decomposition of accumulated organic substances that do not decompose into simple compounds available for disposal by bacteria. It must be remembered that the effectiveness of disinfection when large quantities dissolved organic matter decreases, because Ozone is primarily consumed for its oxidation. By general principle An ozonizer is electrodes separated by a dielectric, to which voltage is supplied from a high-voltage transformer. As a result of an electrical discharge in the air driven through the gap between the dielectric and the electrode, ozone molecules (O3) are formed. Ozone-enriched air is supplied through a sprayer into the water of the aquarium system.

Ultraviolet irradiation of water (using a special UV sterilizer) compared to ozonation is a simpler and more reliable method of sterilization. It kills microorganisms in water, but is not able to penetrate to a depth exceeding 5 cm. This determines the design of the UV sterilizer, which in general is as follows. An ultraviolet lamp is placed in a quartz tube in a flask that has pipes for water inlet and outlet; a gap of several millimeters is left between the walls of the flask and the quartz tube for water flow. And this entire structure is enclosed in a protective casing for human safety. The UV sterilizer completes the water treatment process in the filtration circuit. About UV sterilizers, see the article by Yuri Frolov.

The UV sterilizer is also known as a remedy against “water blooms” and “bacterial turbidity”. But at the same time, you need to understand that it does not solve the problems of biofiltration, but only kills microorganisms in the water. Although there is an opinion that in case of severe turbidity, ultraviolet plays a positive role, eliminating “wrong” microorganisms from aquarium water and thus making life easier for the “correct” ones living in the biosubstrate. The negative role of a UV sterilizer is that it can create the illusion of “crystal clear” water, which in fact is not such. Let us note here that in a cichlid aquarium without living plants, even with powerful filtration and zero ammonia and nitrite, the water may look slightly cloudy. And in this aspect, a UV sterilizer is a good addition to a filtration system.

Does a UV sterilizer pose a risk to beneficial nitrifying bacteria? No, because these microorganisms, as just noted, mostly live on the substrate, i.e. in the biofilter and in the soil, and only a certain amount of them are “free floating”. However, according to general rule The UV sterilizer should be installed at the outlet of the external filter, and not at the inlet, so as not to interfere with the migration of nitrifying bacteria from the aquarium to the filter.

Lecture No. 18.

Sterilization, water production, stabilization.

Sterilization– according to GF XI, this is the process of killing or removing from an object microorganisms of all types at all stages.

In the Global Fund XI, the article “Sterilization” includes the following methods:

Thermal (steam, air)

Chemical (gases, solutions)

Filtration

Radiation method

Thermal methods of sterilization.

- air sterilization – sterilization with dry hot air in drying and sterilization cabinets, temperature 160 0, 180 0, 200 0 C (for the device, see pages 339-341). With this method, all microorganisms die due to the pyrogenetic decomposition of proteins.

It applies to:

Disadvantage: you cannot sterilize water and solutions, because air is a poor conductor of heat, heating is uneven.

- steam sterilization – carried out with saturated water vapor at a pressure greater than atmospheric.

There is a combined effect high temperature and humidity, therefore death occurs at a lower temperature. As steam pressure increases, temperature increases.

1 ATI (excess atmosphere)

1 kg s/cm 2 (kilogram force)

1.1 kg s/cm 3

the temperature values ​​correspond to the indicated pressure if the steam is pure and not a mixture of steam and air. The more air, the lower the temperature, so the air is displaced by steam, the valve is closed and steam is admitted into the sterile chamber. After the sterilization period has expired, the tap is opened and the steam is released. The pressure gauge is set to 0, the chamber is unloaded.

Application:

Conducted in containers and jars. The materials are not stacked tightly, the biks must be open. Marked (date, sterilization mode). Afterwards they are closed and stored for no more than 3 days. After opening, use within 24 hours.

N.B! in exceptional cases, sterilization at lower temperatures is allowed. Indicated in the technical documentation, 100 0, atmospheric pressure, flowing steam. There is no guarantee of complete sterilization.

Monitoring the effectiveness of thermal methods.

It is carried out using measuring instruments, chemical and biological tests.

Chemical tests - use substances that change color or physical state at a certain temperature (a mixture of benzoic acid and fuchsin 10:1, am. Place in a sterilizer. If the mixture has melted, the color has changed, therefore the temperature is 120 0. The melting point of benzoic acid is 122-124 0, sucrose, thiourea, succinic acid melt at 180 0.

Chemical methods of sterilization.

- gas sterilization – gas sterilizers use pure ethylene oxide or a mixture with methyl bromide 1:2.5. The mode depends on the gas concentration.

With a sterilizing dose of ethylene oxide of 1200 mg/dm 3, the sterilization time is 16 hours at a temperature of 18 0. The mixture at a temperature of 55 0 4 hours, at a sterilizing concentration of 2000 mg/dm 3.

Objects are sterilized in bags made of polyethylene and parchment, rubber, polymer materials, and glass.

Flaw: Gases are toxic, degassing is necessary after sterilization.

- sterilization with solutions . Carry out in closed containers made of glass or plastic with the product completely immersed for the duration of the sterilization exposure. After sterilization, the product must be washed with sterile water under aseptic conditions. Products made of rubber, glass, and corrosion-resistant materials are sterilized.

I sterilize with solutions of hydrogen peroxide and deoxone, NAD acids.

Sterilizing solution of hydrogen peroxide (H 2 O 2): at 18 0 - 360 minutes

at 50 0 - 180 minutes

Dezoxon sterilizing solution (1% solution): at 18 0 - 46 minutes

Sterilization by filtration.

Solutions of thermolabile substances are sterilized, because for them this is the only way. Microbial cells are considered as insoluble particles that can be separated from the liquid mechanically. Several pre-filters with large pore diameters are placed in front of the sterilizing filter. All filters are divided into two groups:

Membrane

Deep

Membrane. They are characterized by a sieve mechanism for retaining microbial cells. The maximum pore diameter is no more than 0.3 microns. They are thin disks made of polymer materials (Vladipor, cellulose acetate). Special pressure filtration units are used.

Deep. Ceramic, porcelain, asbestos, paper. Complex retention mechanism (sieve, adsorption, inertial). Filtration is carried out under vacuum.

Radiation sterilization.

Not used in pharmacies. It is used for plastic products, dressing materials, and products for disposable use in packaging. Irradiation in packaging at g-installations, proton accelerators and other sources of g-rays, radioactive isotopes Co 60, Cs 137.

The State Fund XI contains an article “Sterility Test”. Control is carried out 2 times a month at the SES.

Solvents for injection solutions.

Water for injection, vegetable oils (in pharmacies), water oils, ethers (benzyl benzoate, ethyl oleate), alcohols, glycerin (in factories) are used.

Water for injections

Aquae pro injectionibus

Must pass all tests for purified water and be pyrogen-free. Pyrogenic substances are not volatile, do not distill with steam, contamination can occur when water droplets are transferred or condensate is carried away, therefore the droplet phase is separated from the steam phase. To do this, special spray traps (separators, reflectors) are installed in the devices along the steam path. They are:

Film

Volumetric

Centrifugal

Combined

Film - a set of plates of various sizes through the holes of which steam passes.

Centrifugal - a rotational movement of the separated steam is created, the drops are separated.

Volumetric - droplets fall out of the steam stream under the influence of gravity, because the steam path lengthens.

The production of pyrogen-free water is ensured by careful separation of steam passing through reflective screens located in the upper part of the evaporation chamber. Water purification from pyrogenic substances is carried out by adding chemical reagents (potassium permanganate, sodium dihydrogen phosphate (NaH 2 PO 4)). There are dropper dispensers for them.

Only freshly distilled water for injection is used and stored for 24 hours under aseptic conditions.

Non-pyrogenic water distillers are located in the aseptic distillation room.

Water for injection is monitored daily by an analyst (absence of chlorine, calcium, reducing substances, sulfate ions, ammonium salts, carbon dioxide). A complete chemical analysis is carried out once a quarter. Non-pyrogenicity - once a quarter at the SES.

Stabilization of solutions for injections.

During the process of sterilization and storage, decomposition of substances is possible: sediments and toxic products may form, color and properties may change. With an increase in temperature for every 10 0 C, the speed chemical reaction increases by 2-4 times, therefore, chemical changes are accelerated many times during sterilization.

Two main degradation pathways: hydrolysis and oxidation.

Salts in which one or both components are weak undergo hydrolysis. If the components are strong, then hydrolysis does not occur.

If, after a specialized laboratory analysis, the presence of viruses, bacteria, or pathogens is detected in the water supply, then you must immediately contact the management company or the responsible service company. That's why anyone to modern man It will be useful to know about effective technologies that will help solve the problem locally, in your own home or apartment.

Basic methods of disinfection and sterilization

Almost any of our compatriots, even a child, knows that unpleasant odors and tastes in the water of their municipal networks are created by chlorine. This substance is used specifically to destroy viruses, bacteria, and other microorganisms. It is strong poison, but is inexpensive. Thus, at a relatively low cost of the disinfectant composition, you can obtain the desired effect disinfection and sterilization without significant costs.

Alternative technologies appeared at the beginning of the last century. The first industrial installations appeared at this time almost simultaneously in France and Germany, and Scientific research, confirming the effectiveness of this method were produced at the end of the 19th century. In Russia, the introduction of similar technologies began several decades later. The effect of radiation on microorganisms depends on its intensity and duration of exposure. Specialists use special tables that help them accurately calculate the required parameters for each individual installation.

This technique involves passing the appropriate gas (O3) through water under pressure. Ozone in high concentrations is also toxic. It destroys a wide variety of microorganisms effectively. Its additional capabilities should also be noted. This gas accelerates oxidation processes, so it can be converted into an insoluble form when present and can subsequently be retained by conventional filters.

Comparison of different methods

To destroy all microorganisms, a sufficient concentration of toxic substances or an appropriate intensity of ultraviolet radiation is required. But in any case, the characteristics of the source used should be taken into account.

For example, it was previously believed that groundwater is well purified from all kinds of microbial contaminants. However, accurate research confirms that some forms of viruses are capable of penetrating through numerous layers of soil to great depths. Surface water more polluted. They contain pathogens of a wide variety of diseases. If such sources are used, it is recommended to use multi-stage purification systems with primary and final chlorination, sedimentation, coagulation and filtration of small particles. In practice, mechanical increases in chlorine doses to maximum values ​​are often used.

A high concentration of this substance in itself poses a danger to human body, and for parts of the water supply system, individual equipment units, filter elements, cartridges. A similar situation must be taken into account when using ozone. This poisonous gas provokes the emergence and development of oxidation processes, which contributes to the emergence of corrosion centers. Unlike these, ultraviolet radiation will be safe at any intensity. It won't change chemical composition liquids, but will also provide high level epidemiological safety for all groups of microorganisms.

Let us note a few more factors that should be considered when choosing equipment:

• Disinfection and sterilization of water can be easily automated. In this case, it is necessary to monitor only electrical parameters (operability of lamps, circuit integrity and other values). This is much easier and cheaper to do than ensuring dosage accuracy when supplying chlorine or ozone;
• Chlorine provides (unlike ozone and ultraviolet radiation) a long-lasting effect on water. However, the effectiveness of its residual concentrations on microorganisms should not be exaggerated. If its content does not exceed the standards established by the domestic GOST, then it will not be able to function as an effective barrier in case of secondary contamination of the liquid;
• Ozonation and chlorination are accompanied by the creation of a wide range of different compounds, some of which are themselves poisonous or carcinogenic;
• Viruses are best removed using ultraviolet radiation, or ozonation;
• The cheapest technology is chlorination.

Based on the information presented here, some conclusions can be drawn, but the study will be incomplete if we do not talk about other modern technologies. With their help, disinfection and sterilization of water are carried out at home.

New disinfection and sterilization technologies and additional capabilities

The first technique is reverse osmosis. In this type of installation, membranes with very small holes are installed. Their size does not allow anything larger than water molecules to pass through. Of course, not only helminths and other relatively large microorganisms, but also small viruses are unable to penetrate such a reliable barrier. However, if additional protection is needed, you can purchase and install a special unit with ultraviolet lamp. It is installed as a final processing step.

Disinfection and sterilization of water using this technology is only possible on a relatively small scale. The most productive reverse osmosis plants are not capable of processing more than 200-220 liters of water per day. This will not be enough to fully meet all the needs of the family. Even prolonged boiling does not destroy some types of microorganisms. The hepatitis virus has a special protein shell that can withstand temperatures of +100°C without destruction long time. This procedure, in addition to everything, is also quite expensive. You cannot use it for daily showering or performing other hygiene procedures.

If you have hard water at home and it is necessary to destroy bacteria, then you can solve both problems at the same time with the help of a new one. This is available to Aquashield devices from the professional series (Pro). The presence of such an abbreviation in the name indicates increased intensity magnetic field, created by the generator and coil. It converts hardness salts in such a way that they stop combining in the form of scale when heated. Thus, the first task is solved, eliminating the harm of increased rigidity.

Let's take a closer look at how this happens. When a microorganism passes through an intense magnetic field, formation occurs on the surface of the microorganism. electric charge. It attracts particles with a different charge sign, which leads to a rapid increase in the thickness of the shell. This disinfection and sterilization technology increases the osmotic pressure inside the bacteria to a critical level. The shell breaks and the microorganism dies.

As you can see, if you carefully monitor new products in the relevant field, you will be able to get the desired result without unnecessary costs and precautions. Electromagnetic converters are absolutely safe. They perform all their functions fully without changing the chemical composition of the water.