Review of modern methods of drinking water disinfection

The use of modern methods of disinfection of drinking water allows you to get rid of viruses and bacteria that pose a danger to humans. The destruction of pathogenic agents can occur partially or completely, depending on the initial quality of the liquid and the tasks set.

The need for disinfection

The rapid development of technology and industry has led to environmental pollution. Fresh water sources (surface or underground) are contaminated with pathogens, chemical compounds or have an unpleasant sediment. In their natural form, they are not suitable for drinking and can harm human health.

The use of water disinfectants allows you to get rid of harmful microorganisms. Most of the methods are used for the treatment of domestic and industrial effluents. There are modern methods of disinfection that allow the use of prepared water for household needs from centralized water supply.

Normative documents of water-sanitary legislation

The properties of drinking water are controlled and established by law. The main document used to assess its quality is called the Water Code. To control the characteristics of the liquid, other state standards are also applied:

• GOSTs. They contain the norms according to which the quality control of waste and drinking water is carried out.
• SanPiNy. Contains hygienic requirements for the quality of water resources.
• SNiPs. Building codes that determine the rules for the construction of treatment facilities, water supply systems.

In the process of monitoring water characteristics, the Federal Law "On the Sanitary and Epidemiological Welfare of the Population" is necessarily used.

Effective methods of disinfection

There are a huge number of methods by which it is possible to get rid of pathogenic agents in the composition of the liquid. They are conventionally divided into chemical, physical and combined.

Chlorination

It is considered the safest and easiest way to disinfect. Chlorination is very popular in Russia, which is also explained by its following advantages:

• The means used for disinfection are relatively inexpensive.
• High efficiency of the method. After chlorination, the secondary growth of microorganisms does not occur, the appearance of algae is prevented.
• In addition to the pronounced bactericidal effect, after using the method, the water is purified from iron, manganese, and hydrogen sulfide.

Chlorination has several disadvantages. When oxidized, the agents used for cleaning acquire a high degree of mutagenicity and carcinogenicity. When using chlorine compounds, it is not possible to completely get rid of them, which sometimes makes the water unsuitable for drinking, and leads to the pollution of natural sources. Regularly using the liquid purified in this way, a person puts himself at risk of developing oncology, diseases of the gastrointestinal tract, and the cardiovascular system.

Chlorine dioxide is increasingly used for disinfection. The substance is more effective and safer.The only drawback is that it must be used directly in production.

Ozonation

The principle of operation of the method of disinfection is the effect of ozone gas on pathogenic microorganisms. It destroys viruses and bacteria, oxidizes some compounds that give water an unpleasant odor and taste. The advantages of ozonization are its fast disinfecting effect, a high degree of safety for humans and the environment.

Disadvantages of the method:

• an incorrectly selected dosage of ozone leads to the appearance of an unpleasant odor in the treated liquid;
• an excess of ozone provokes metal corrosion in water pipes, household appliances;
• the gas used for cleaning belongs to the first class of hazard.

Ozonation is an expensive method of disinfection. The maintenance of the used installations requires high expenses.

Other chemical techniques

When choosing a method of disinfection, you should pay attention to the following options:

• The use of ions of heavy metals, bromine, iodine.
• Disinfection with strong oxidants - sodium hypochlorite.
• Disinfection using ions of noble metals - silver.

Biopag is the most popular drug used to destroy pathogens in a liquid medium. Most often used for swimming pools, water parks, aquariums. This cleaning method is chosen for its safety and ease of use. After using it, the water does not acquire an unpleasant odor or taste. The disadvantage of this method is that after cleaning the liquid can cause irritation of the skin or mucous membranes.

Ultraviolet

Before exposure to UV rays, the liquid is pre-filtered and coagulated. This helps to get rid of large particles and helminth eggs. Subsequently, they switch to physical disinfection using ultraviolet radiation. It is important to correctly calculate the amount of energy that needs to be applied to treat a given volume of water. The duration of exposure to UV radiation also depends on the number of pathogenic microorganisms in each milligram of liquid.

The water disinfection unit consists of special lamps placed in quartz covers. The efficiency of the equipment depends on the quality of the liquid. The more transparent it is, the further the radiation spreads. Such installations require regular maintenance (once every three months).

The advantage of the method is the possibility of its individual use. UV lamps have a long service life (thousands of hours). Also, this method of disinfection is ideal for field conditions. To perform natural cleaning, it is enough to place the container with liquid in direct sunlight for 6 hours.

Ultrasound

The method is based on the effect of cavitation. Certain sound frequencies are capable of creating voids that form large differences in pressure. This leads to the rupture of the cell membranes of pathogenic viruses, bacteria and to their death.

The value of the ultrasonic cleaning method for the industry is insignificant. The method is expensive and difficult to use.

Electropulse disinfection method

Water purification is carried out using electrolysis. An electric discharge is applied to the liquid, which forms a shock wave. Pathogenic microorganisms that fall under its influence die.

The advantage of the method is called its effectiveness when exposed to turbid water. Before disinfection, the liquid does not require preliminary cleaning. After electrolysis, even very tenacious bacteria die, and the positive effect of the procedure lasts up to 4 months. The disadvantage of this method is called its high cost.

Thermal impact

Boiling is a handy method of disinfection. The thermal effect allows you to improve the properties of the liquid from a well, a well, a water supply system.With the help of boiling, it is possible to get rid of almost all harmful microorganisms. After exposure to heat, the hardness of the water is significantly reduced while maintaining its taste.

Handy disinfection methods

To purify water from pathogens in the field, you can use regular hydrogen peroxide. It is added in the amount of 1 tablespoon per 1 liter. Then the liquid is defended for an hour. To accelerate the decomposition of peroxide, add 1-2 tablets of activated carbon to the water.

Method selection

Before using a specific disinfection method, the original water quality is taken into account. The characteristics of the liquid to be obtained from the purification are taken into account. These requirements are set out in the regulatory documentation for water used for drinking or household needs for swimming pools.

The selection of methods also takes into account the allowable capital and operating costs. Many methods of disinfection (using ultraviolet radiation, ultrasound) require the involvement of expensive equipment, specially trained personnel.