Disinfection and water disinfection are the same process. It is aimed at the complete or partial destruction of viruses, bacteria contained in the liquid, cleaning it from dust, debris, etc. The purpose of the event is to protect people from viral and infectious diseases, food poisoning, and helminthic invasion. In this article, we will introduce you to several methods of water disinfection - traditional and innovative, industrial and suitable for use in the field.
Cleaning methods
First of all, we note the fact that the complete purification of all the elements contained in it (including bacteria) will make the liquid completely unsuitable for drinking and cooking. That is why it is necessary to properly choose the method of water disinfection, to be sure of its high-quality implementation.
Disinfection should always be preceded by a chemical and biological examination of the liquid. Based on its results, one of the disinfection methods is chosen:
- Chemical, reagent.
- Combined.
- Reagent-free, physical.
Each of them is a way of water disinfection, but according to its own specific method. For example, chemical is exposure with the help of coagulant reagents, physical methods are non-reagent exposure. There are also innovative ones, which we will definitely analyze throughout the material.
It is interesting to use combined methods - this is the use of both physical and chemical cleansing alternately. It is considered today the most effective in disinfection - not only allows you to get rid of bacteria, but also helps to prevent their repeated visit. The use of several methods of water disinfection is also a guarantee of its purification from the maximum amount of pollutants.
Chemical Methods
In particular, this is the treatment of liquid with various substances - chemical coagulants. Most common:
- chlorine;
- ozone;
- sodium hypochlorite;
- metal ions, etc.
The effectiveness of these methods of disinfecting drinking water depends on the most precisely defined dose of the acting reagent, on the proper time of its contact with the treated liquid.
The appropriate dosage is determined both by the calculation system and by the trial disinfection, after which the water is taken for analysis. It is important not to miscalculate in the sense that a small dose of chemical reagents is not only powerless against viruses and infections, but can also help increase their activity. For example, the same ozone inin small quantities, kills only part of the bacteria, releasing special compounds that awaken dormant microorganisms, stimulating them to accelerate reproduction.
From here, the dose is always calculated in excess. But it is one thing - ways of disinfecting wastewater, and another thing - drinking water. The excess must, in the latter case, be such as not to cause poisoning by disinfectants in people who consume the liquid.
We invite you to learn more about the chemical technique.
Chlorination
If you ask the townsfolk: "Indicate the easiest way to disinfect water", many will immediately note chlorination. And for good reason - as a method of disinfection, it is very common in Russia. This is explained by the undoubted advantages of chlorination:
- Easy to use and maintain.
- Low price of the active ingredient.
- High efficiency.
- The effect after application - the secondary growth of microorganisms does not occur even with a minimal excess dose of chlorine.
- Control over the smell, taste of water.
- Keeping filters clean.
- Algae prevention.
- Destruction of hydrogen sulfide, removal of iron and manganese.
However, the tool has its drawbacks:
- When oxidized, it has a high degree of toxicity, mutagenicity, carcinogenicity.
- The subsequent purification of the liquid with activated carbon after chlorine does not completely save it from the compounds formed by chlorination. High resistant, they can make drinking waterundrinkable, litter rivers and other natural water bodies downstream.
- The formation of trihalomethanes, which have a carcinogenic effect on the human body. They are what promote the growth of cancer cells. And boiling, the easiest way to disinfect water, exacerbates the situation. Dioxin, a dangerous toxic substance, is formed in the chlorinated liquid after it.
- Research shows that chlorinated water also contributes to the development of diseases of the vessels, gastrointestinal tract, liver, heart, hypertension, atherosclerosis. Negatively affects the condition of the skin, hair and nails. Breaks down protein in the body.
Today, a modern replacement is chlorine dioxide, which is more effective in disinfection. But a significant disadvantage is that it must be applied immediately at the place of production.
Ozonation
Many consider ozonation to be the most reliable way to disinfect water. Ozone gas can destroy the enzyme system of a microbial, viral cell, oxidize some compounds that give the liquid an unpleasant odor.
The advantages of the method are as follows:
- Quick Disinfection.
- Maximum disinfection for humans and the environment.
At the same time, ozonation has a number of disadvantages:
- If the dosage is incorrect, the water has an unpleasant odor.
- Excess ozone contributes to increased metal corrosion. This also applies to water pipes, and household appliances, dishes. It is necessary to wait for the period of gas decay,before running water through the pipes.
- Quite an expensive method to use - requires large waste of electricity, sophisticated equipment, highly qualified service personnel.
- The gas in the production process is toxic and explosive. Refers to the first class of danger.
- After ozonation, bacteria may re-grow. No guarantee of 100% water purification.
Polymer antiseptics
Another popular chemical method is the use of polymeric reagents. The most famous today is Biopag. Most often it is used in public swimming pools, water parks.
Advantages of this method of water purification and disinfection:
- Does no harm to human and animal he alth.
- Does not impart a particular odor, taste or color to water.
- Quite easy to use.
- Does not corrode metal.
- Does not cause allergic reactions.
Disadvantages - may irritate the skin, mucous membranes.
Other chemical methods
What methods of water disinfection can be called in this case? These are several options:
- Disinfection with heavy metal ions, iodine, bromine.
- Disinfection with noble metal ions. The most commonly used is silver.
- Use of strong oxidizers. A common example here would be sodium hypochlorite.
Physical methods
Here will beinclude non-chemical means of influencing microorganisms in liquids. Their use is most often preceded by filtration and coagulation of water. This removes particulate matter, worm eggs, and a large proportion of the microbes in the liquid.
Most common ways:
- Exposure to ultraviolet radiation.
- Exposure to ultrasound.
- Boiling. An effective way to disinfect water in natural conditions.
Let's take a closer look at each of them.
UV irradiation
It is important to calculate the required share of the influencing energy for a certain volume of water. To do this, multiply the radiation power and the time of contact with the liquid. It is important to first determine the concentration of microorganisms in 1 ml of water, the number of indicator bacteria (in particular, Escherichia coli).
Note that UV rays will have a detrimental effect on microorganisms better than chlorine. Ozone, according to the results of purification, will be equal in efficiency to irradiation. UV rays affect both enzyme metabolism and the cell structures of bacteria and viruses. What is important, they destroy vegetative, spore forms.
The advantages of the method are as follows:
- There is no upper dose threshold, since such irradiation does not form toxic compounds in water. By increasing it, you can gradually achieve the best results.
- Great for personal use.
- Long lamp life of several thousand hours.
But there are also disadvantages:
- No consequences of the event - to discouragereturn of microorganisms, the water should be disinfected periodically and systematically without turning off the unit.
- Quartz lamps are sometimes contaminated with deposits of mineral s alts. However, this can be easily prevented with regular food acid.
- Preliminary purification of water from particles suspended in it is mandatory - screening the rays, they nullify the whole process.
The method of disinfecting water in the field using UV radiation is shown in the picture.
Ultrasound
The action here is based on cavitation. This is the name of the ability of a number of sound frequencies to form voids that create a large difference in pressure. This dissonance leads to a rupture of the cell membranes of viruses, bacteria, which leads to the death of microorganisms. Efficiency depends on the intensity of sound vibrations.
This method is not widely used, primarily because of its high cost. Certain equipment and specially trained personnel are required. It is important to remember that ultrasound is dangerous for bacteria only at certain frequencies. Low waves, on the contrary, can cause an acceleration in the growth of the number of microorganisms in the water.
Boiling
The easiest and most common way to disinfect water in the field is, of course, boiling. Its popularity and recognition is based on many factors:
- Destruction in the liquid of almost all harmful microorganisms - viruses, bacteria and bacteriophages, antibiotics, etc.
- Availability - You need a heat source that can heat water up to 100 degrees Celsius and a heat-resistant container.
- Does not affect the taste of the liquid, its color and smell.
- Eliminates gases dissolved in water.
- Excellent fights the hardness of the liquid, softens it.
Complex cleaning methods
From simple methods of water disinfection, let's move on to complex ones, which are the most effective in some cases. For example, this is a combination of UV irradiation and chlorination, ozonation and chlorination (prevention of secondary infection), reagentless and reagent methods.
Filtering is often included in the same category. But with the peculiarity that each filter cell must be smaller in size than the microorganisms to be screened out. This means that its diameter should not exceed 1 micron. But in this way you can only fight bacteria. More microscopic pores are used against viruses - with a diameter of less than 0.1-0.2 microns.
A filtration system called "Purifier" is popular on the modern market. The device differs in that it uses several water filtration systems, its disinfection. Some models can additionally cool water up to 4 degrees and heat up to 95 degrees.
The installation is applicable to both industrial and office, home scales. It is enough to simply connect it to the water pipe with a plastic adapter. Manufacturers assure that the purchase, connection and operation of the Purifier willcost the owner less than delivering bottled water.
Innovative disinfection methods
The newest methods of water disinfection today will be electrochemical and electropulse. In the domestic market, they are used in devices such as "Emerald", "Sapphire", "Aquamarine".
Their operation is based on the operation of a special electrochemical diaphragm reactor, through which water is passed. It, in turn, is separated by a metal-ceramic membrane, which is capable of producing ultrafiltration into the cathode and anode zones.
At the moment when current is supplied to the anode and cathode chambers, solutions begin to form in them - alkaline and acidic. Then - electrolytic formation (its other name is active chlorine). This whole environment is distinguished by the fact that the overwhelming number of species of harmful microorganisms actively die in it. It is also able to destroy some compounds dissolved in the liquid.
The performance of the presented devices mainly depends on two factors: the number of working elements and their design. In some units, catholytes and anolytes are used (mainly in the medical field). Such decontamination is called ECA technology.
By the way, many misconceptions are connected with it. Some device manufacturers claim that the water treated in their unit becomes healing and even miraculous. However, in reality, it is only cleared anddecontaminated.
Electropulse cleaning is the transmission of an electric discharge through the water column. Ultra-high pressure shock wave, light radiation, ozone formation - a consequence of exposure. Together, this is detrimental to microorganisms suspended in the liquid.
We got acquainted with different methods of water disinfection - simple and complex, traditional and innovative, effective and safe for humans. Each of them has its own advantages and disadvantages. However, the leading factor is harmlessness to the human body, the environment.
