You're probably used to buying paint either by brand or by color like Benjamin Moore or blue.

But when it comes to coating your walls and ceiling, there's a much bigger decision you need to make that has to do with the chemicals actually used to make the paint itself.

One of the most toxic is actually a group referred to as "Volatile Organic Compounds" or VOCs.

VOCs are a large group chemical substances based on carbon, which evaporate easily at room temperature, making them easy to inhale. Some of the most common sources of VOCs in our homes are household paints. VOCs are used as solvents or thinners that work together with resins to bind together all the paint ingredients and make them adhere to the wall. In other words, they can improve performance and durability.

However, the VOC "gases off" into the air while the paint dries. Most people can smell high concentrations of some VOCs, although other VOCs are odorless. The smell doesn't indicate how dangerous the chemicals are, says the Minnesota Department of Health. No matter how strong they smell, many VOCs, which can include formaldehyde, acetone, benzene, and perchlorethylene, can make you sick in a variety of ways.

That's why I've put together this list of 6 reasons why you should never use paint that contains VOCs.

1) Worsening of asthma symptoms. If you already suffer from asthma, breathing air contaminated with VOCs can trigger an asthmatic reaction. Scientists studied 400 toddlers and preschoolers and found that children who inhaled smoke from water-based paints and solvents were two to four times more likely to suffer from allergies or asthma.

2) The appearance of flu-like symptoms. Even if you don't suffer from asthma, you may experience a runny nose, itchy eyes, joint pain, and other flu-like symptoms from inhaling paint fumes. Solvents that evaporate into the air from paint are absorbed into the lungs when inhaled and then into the bloodstream. They can irritate your eyes, nose, and throat and make you feel as if you've contracted the flu.

3) Potential cancer causing. Many chemicals in the VOC family are considered carcinogenic by the US Protection Agency. environment USA. According to the World Health Organization, professional painters face a 20 percent increased risk of contracting a number of cancers, especially lung cancer.

4) Dizziness and loss of consciousness. Sometimes the chemicals that release gas in VOC paints are so overwhelming that they make people feel very dizzy and, in extreme cases, pass out. This can be especially dangerous if you were at the top of the stairs, perhaps while painting the ceiling, where you inhaled paint fumes very close to the source.

5) Problems of infertility. A study from the University of Sheffield and Manchester suggests that men who are regularly exposed to chemicals in paint may be more prone to fertility problems. Painters and decorators are the main victims. However, researchers found a 250 percent increase in "sperm motility risk" among men exposed to chemicals widely used as thinners for water-based paints, which would give any guy a break from using paints containing VOCs.

6) The problem of "dementia painter". In addition to an increased risk of lung cancer, painters can develop a neurological condition triggered by long-term exposure to paint thinners called painter's dementia.

What can you use instead

You might decide to ditch paints that contain VOCs because that would be right for your painter!

Increasingly, you can buy VOC-free paint online and in stores that specialize in supplying healthy and environmentally friendly building materials. Consumer Reports offers this helpful VOC content guide to choose from when you're shopping; if you are a subscriber, you can see how they rate the various no or low VOC paints that are available on the market.

Most of the major brands, including Home Depot, Benjamin Moore, and Pittsburgh Paints, have made VOC-free choices. Just be careful when the paints are mixed, as the base paint may be VOC-free, but the pigment color may contain VOCs. You want the entire mixture to be VOC-free.

Water-based paints will have fewer VOCs than oil-based paints. However, there is no guarantee that just because the paint is water based, it will be VOC free. You must explicitly ask for VOC-free paint before you buy.

Whatever paint you use, make sure the room or house is well ventilated while painting. Turn on fans and open windows and doors. If possible, don't sleep in a room that has been freshly painted; especially don't sleep or use the room if the paint on the walls isn't completely dry. If you wake up with a headache or discomfort, stay out of the room for several days until you are sure it is odor free.

INTERSTATE COUNCIL FOR STANDARDIZATION, METROLOGY AND CERTIFICATION

INTERSTATE COUNCIL FOR STANDARDIZATION, METROLOGY AND CERTIFICATION

GOST

INTERSTATE

STANDARD

31991.1-

(ISO 11890-1:2007)

PAINT MATERIALS

Determination of volatile organic content

compounds (LOS).

difference method

(ISO 11890-1:2007, MOD)

Official edition

Standartinform

Foreword

The goals, basic principles and procedure for carrying out work on interstate standardization are established by GOST 1.0-92 “Interstate standardization system. Basic Provisions” and GOST 1.2-2009 “Interstate Standardization System. Interstate standards, rules and recommendations for interstate standardization. Rules for the development, adoption, application. updates and cancellations

About the standard

1 PREPARED by the Technical Committee for Standardization TC 195 "Paint and varnish materials". OJSC "Scientific and Production Company "Spektr LK" based on an authentic translation into Russian of the standard specified in paragraph 4, which was made by FSUE "STANDARD-INFORM"

2 INTRODUCED by the Technical Secretariat of the Interstate Council for Standardization, Metrology and Certification

3 ADOPTED by the Interstate Council for Standardization, Metrology and Certification (Minutes of December 3, 2012 No. 54-P)

Short name of the country no MK (ISO E1v6> 004-97	Code of the country according to MK (ISO 31vv) 004-97	Abbreviated name of the national standards body
Azerbaijan		Aztvndart
		Ministry of Economy of the Republic of Armenia
Belarus		State Standard of the Republic of Belarus
Kazakhstan		State Standard of the Republic of Kazakhstan
Kyrgyzstan		Kyrgyzstvndvrt
		Moldoav-Standard
		Rostvndvrt
Tajikistan		Tajikstandart
Uzbekistan		Uzstvndvrt

4 This standard has been modified with respect to international standard ISO 11890-1:2007 Paints and varnishes - Determination of volatile organic compound (VOC) content - Part 1: Difference method

Additional words, phrases included in the text of this standard to meet the needs national economy and features of national standardization are in italics.

Table 1 "Results of the interlaboratory test", containing reference data, has been excluded from section 10.

This standard has been prepared on the basis of GOST R 52485-2005 (IS011890-1:2000) “Paint-and-lacquer materials. Determination of the content of volatile organic compounds (VOC). Difference method”, taking into account the requirements of ISO 11890-1:2007.

The international standard was developed by the Standardization Committee TC 35 "Paints and varnishes".

Translation from in English(ep).

Compliance degree - modified (MOD)

5 Order federal agency Law on Technical Regulation and Metrology dated August 7, 2013 No 482-st interstate standard GOST 31991.1-2012 (ISO 11890-1:2007) was put into effect as a national standard Russian Federation since July 1, 2014

6 INTRODUCED FOR THE FIRST TIME

Information about changes to this standard is published in the annual information index "National Standards", and the text of changes and amendments - in the monthly information index "National Standards". In case of revision (replacement) or cancellation of this standard, a corresponding notice will be published in the monthly information index "National Standards". Relevant information, notification and texts are also placed in information system common use- on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet

© Standartinform. 2014

In the Russian Federation, this standard cannot be fully or partially reproduced. replicated and distributed as official publication without the permission of the Federal Agency for Technical Regulation and Metrology

GOST 31991.1-2012 (ISO 11890-1:2007)

INTERSTATE STANDARD

PAINT MATERIALS

Determination of the content of volatile organic compounds (VOC).

difference method

paint materials. Determination of volatile organic compound (VOC) content. Difference method

Introduction date - 2014-07-01

1 area of ​​use

This International Standard specifies a method for the determination of the content of volatile organic compounds (VOCs) in paints and varnishes and their raw materials. This method is used for the expected mass fraction VOC more than 15%. If the expected mass fraction of VOCs is from 0.1% to 15%. use the method according to GOST 31991.2.

The method is based on the assumption that the volatile substance is water or an organic compound. If other volatile inorganic compounds are present in the material, their content is determined by another more suitable method and the results of such determination are taken into account in the calculations.

2 Normative references

This standard uses normative references to the following interstate standards:

GOST 9980.2-86 (ISO 842-84, ISO 1512-74, ISO 1513-80) Paintwork materials. Sampling for testing (ISO 842:1984 Raw materials for paints and varnishes - Sampling. MOD: ISO 1512.1974 "Paints and varnishes - Sampling". MOD: ISO 1513:1980 "Paints and varnishes - Inspection and preparation of test samples .MOD)

GOST 14870-77 Chemical products. Methods for the determination of water (ISO 760:1978 "Determination of water - Karl Fischer method (general method). NEQ)

GOST 29317-92 (ISO 3270-84) Paintwork materials and raw materials for them. Temperature and humidity conditions for conditioning and testing (ISO 3270:1984 "Paints, varnishes and their raw materials. Temperature and humidity conditions for conditioning and testing". MOD)

GOST 31939-2012 (ISO 3251:2008) Paint and varnish materials. Determination of the mass fraction of non-volatile substances (ISO 3251:2008 "Paints, varnishes and plastics - Determination of the content of non-volatile substances". MOD)

GOST 31991.2-2012 (ISO 11890-2:2006) Paint and varnish materials. Determination of the content of volatile organic compounds (VOC). Gas chromatic method (ISO 11890-2:2006 "Paints and varnishes - Determination of volatile organic compounds (VOCs) - Part 2: Gas chromatic method". MOD)

GOST 31992.1-2012 (ISO 2811-1:2011) Density determination method. Part 1: Pycnometric method

Official edition

Note - When using this standard, it is advisable to check the validity of reference standards in the public information system - on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet or according to the annual information index "National Standards", which was published as of January 1 of the current year, and on issues of the monthly information index "National Standards" for the current year. If the reference standard is replaced (modified), then when using this standard, you should be guided by the replacing (modified) standard. If the referenced standard is canceled without replacement, then the provision in which the reference to it is given applies to the extent that this reference is not affected.

3 Terms and definitions

8 of this standard, the following terms are used with their respective definitions:

3.1 volatile organic compound; VOC: Any organic compound having an initial boiling point less than or equal to 250°C. measured at normal pressure

NOTE The properties and number of compounds to be taken into account depend on the application of the coating material. For each application, limit values ​​and methods for determining or calculating such compounds are established in regulatory (ND) or technical (TD) documents for paintwork material (LKM).

3.3 ready-to-use paintwork material: The paintwork material after it has been mixed, if necessary, with other components and diluted with appropriate solvents and/or thinners in accordance with RD or TD. suitable for application by the appropriate staining method.

4 Essence of the method

After preparing the sample, the mass fraction of non-volatile substances is determined according to GOST 31939. Then the water content is determined according to GOST 14870. After that, the VOC content in the sample is calculated.

5 Required additional information

For any particular application, the test method specified in this International Standard. must be supplemented with the necessary information. A list of additional information is given in Appendix A.

6 Sampling

Take an average sample of the material for testing (or each material in the case of a multilayer system) according to GOST 9980.2.

Control and preparation of each sample - according to GOST 9980.2.

7 Testing

7.1 Preparation of the paint sample for testing

For testing, a sample of paintwork materials is used. ready for use (3.3).

7.2 Number of determinations and test conditions

Two parallel tests are carried out at a temperature (2312) * C and relative humidity (5015)% (GOST 29317). unless otherwise specified.

7.3 Determining parameters

Determine the parameters necessary for the calculation (8.2-8.4), as required by the requirements of 7.4 and 7.5. Some parameters can be determined by the difference of their values ​​depending on the nature of the compounds. present in the sample.

7.4 Density

If required for calculation (b.3.8.4). determine the density of the sample according to GOST 31992.1. Density determination is carried out at a temperature of (2312) °C, unless other conditions are specified.

7.5 Mass fraction non-volatile substances

Determine the mass fraction of non-volatile substances in a sample ready for use, according to GOST 31939.

6 in the case of one-component coatings, the mass fraction of non-volatile substances in the sample, ready for use. determined according to GOST 31939.

In the case of determining the mass fraction of non-volatile substances in a sample ready for use of multicomponent systems, thoroughly mix the components in accordance with the manufacturer's instructions. Samples are immediately weighed in accordance with GOST 31939. Samples for analysis are kept in cups. in which weighing was carried out, for 1 hour at a temperature of (23 ± 2) ® C and atmospheric pressure. unless otherwise specified. Then the determination is carried out according to GOST 31939.

If any unusual phenomenon occurs during heating (decomposition or destruction), then, by agreement between the parties concerned, it is possible to use a time and (or temperature) other than those recommended in GOST 31939.

7.6 Mass fraction of water

The mass fraction of water in percent according to GOST 14870 is determined by choosing the reagents so that they do not interfere with the analysis of the compounds contained in the sample. If the composition of such compounds is unknown, they are subjected to qualitative analysis, for example, according to GOST 31991.2.

Notes

1 Typical connections that may interfere with the penetration. are ketones and aldehydes. For right choice reagents should be guided by the information provided by the manufacturer.

NOTE 2 If the properties of the material to be tested are precisely defined and it is known that it does not contain water, then the determination of the water content in it can be omitted, assuming it to be zero.

The composition of the Fisher reagent is indicated in the ND or TD for a specific paintwork material.

8 Calculation

8.1 General

Calculate the VOC content according to the method specified in the RD or TD for the material. If a specific method is not specified in the ND or TD, then the VOC content is calculated according to method 1.

Method 1 is the preferred calculation method because it provides the best precision of the results by eliminating the density operation, which is a potential source of additional errors.

8.2 Method 1: Mass fraction of VOCs. %. in a ready-to-use material is calculated by the formula

VOC = 100 - NV - m w . (1)

where VOC is the mass fraction of VOC in the material ready for use. %;

NV - mass fraction of non-volatile matter (7.5), %; m. is the mass fraction of water (7.6). %.

8.3 Method 2: Mass concentration of VOCs. g / dm 3, in a material ready for use, is calculated by the formula

VOC = (100 - NV 10. (2)

where VOC - mass concentration VOC in the material ready for use, g/dm 3:

NV - mass fraction of non-volatile matter (7.5), %; m w - mass fraction of water (7.6),%:

p t is the density of the sample at a temperature of (23 ± 2) X (7.4). g/cm3:

10 - conversion factor.

8.4 Method 3: VOC content. g/dm 3 , in a ready-to-use material, except for water. calculated according to the formula

where LOS,. - content of VOC 6 in the material ready for use, with the exception of water, g / dm 3: NV - mass fraction of non-volatile substance (7.5). %; mw is the mass fraction of water (7.6). %;

p, is the density of the sample at a temperature of (23 ± 2) °C (7.3). g/cm3:

P i is the density of water at a temperature of 23 ° C. g/cm 3 (p w - 0.9975 g/cm 3);

1000 - conversion factor.

9 Processing results

If the results of two parallel tests differ by a value greater than that specified in 10.2. the test is repeated.

Calculate the average of the two valid replicate results and report the result to the nearest 1%.

10 Precision

10.1 Limit of repeatability of results r

The limit of repeatability of results r is the value below which it is expected to be absolute value the difference between the results of two separate tests, each of which is the average of the results of two replicate determinations obtained on identical material by one operator in one laboratory over a short period of time using one standardized test method.

The repeatability of the results for five repeated determinations by this method, expressed as a coefficient of variation in repeatability, is 1%.

10.2 Reproducibility limit R

The reproducibility limit R is the value below which the absolute value of the difference between the results of two tests, each of which is the average of the results of two replicate determinations obtained on identical material by operators in different laboratories, using the same standardized test method, is expected to fall.

the reproducibility of the results by this method, expressed as the reproducibility variation coefficient, is 2%.

11 Test report

The test report must contain:

b) information necessary to fully identify the material being tested (manufacturer's name, trademark, lot number, etc.);

c) supplementary information items referred to in Annex A:

e) the test results of Clause 8, the calculation method used (8.2, 8.3 or 8.4);

0 any deviation from the specified test method:

e) the date of the test.

Annex A (mandatory)

Required Additional Information

In order to be able to use the method of this International Standard, additional information specified in this appendix must be provided.

The necessary information should preferably be agreed between the interested parties, using as its source, in part or in full, the relevant international or national standard or other white paper related to the tested product.

c) Organic compound(s), the content of which(s) should be determined [if it(they) are known^)).

b) Analytical methods to be used to identify these compounds.

c) Calculation method used (section c).

UDC 667.64.001.4:006.354 MKS 87.040 MOD

Key words: paints and varnishes, volatile organic compound (VOC), mass fraction, mass concentration, difference method

Editor L I Nakhimova Technical editor Е.8. Baeprozvainap Proofreader M.v Buinaya Computer airstaa V.I. Grishchenko

Handed over to the set 07/09/2014.

Signed and stamped 27.00.2014. Format 60>S4 "/ I. Headset Ariel. Coin. medical sheet 1.40. Account. Nod. sheet 0.70. Circulation 62 eq. For * 3612.

Published and printed by JSC FSUE STANDARTINFORM. 123995 Moscow. Garnet lane.. 4.

It is no secret that the paints that everyone and everyone has to deal with in the course of repairs in one way or another often contain harmful substances and toxins that adversely affect the environment, our homes and health. Fortunately, modern technologies production paintwork materials(LKM) have gone ahead, many hazardous components in household paints are prohibited, and responsible manufacturers make sure that their products cause as little harm to consumers as possible. It is not difficult to determine such a safe paint, and by following some rules, you can reduce the repair process to minimum risk.

What is paint made of?

Modern paints usually consist of four main components: pigment, solvent, binders and various additives. Pigments are needed to give the desired color, solvents keep the paint in liquid form, binders provide the base and film layer on the surface to be painted. The main potentially hazardous components of the paint are solvents (including those in the binder), as well as additives. Pigments can be harmful if they contain lead or other hazardous metals.

Solvents and additives often contain toxic substances and so-called Volatile Organic Compounds (VOCs) that are harmful to you and me when we breathe them in. Despite the fact that paint and varnish manufacturers have long been making relatively harmless water-soluble paints, on Russian market there are still large quantities of coatings based on alkyd solvents - they are easy to recognize by the pungent smell, so familiar to the Russian nose. Alkyd paint thinner contains dangerous mineral spirits, toluene and xylene, the vapors of which, when inhaled into the body, literally poison it.

Other chemical solvents also have a negative effect; at low concentrations, this manifests itself in excitation, at high concentrations, in headaches, dizziness, drowsiness, irritability, nausea and vomiting. Therefore, alkyd paints are usually used for exterior or industrial applications, as they are more durable and suitable for harsh environments.

Alternative

And yet, toxic coatings are a kind of yesterday in the paint industry. In Europe, for example (the products of European manufacturers are widely represented on the Russian market), at the legislative level they pay great attention to the environmental friendliness and safety of paints. A number of regulations regulate the VOC content of paints of various types, and many manufacturers produce environmentally friendly paints with zero VOC content.

In particular, in residential paint, responsible manufacturers use water as a solvent. Water-soluble paints are very popular all over the world today, as they are the most harmless. In many countries, their share is 70-90% of all produced coatings, in Germany in general 93%. In Russia, this figure is at the level of 30-40%. Oddly enough, but this is also happening because many consumers in the Russian Federation live in captivity of stereotypes, often thinking that paint without a pungent odor cannot be of high quality. The second important factor is the price: alkyd paints are much cheaper. Whether it is worth saving on your health, everyone decides for himself.

Modern water-based paints and varnishes do not contain (or contain very little) VOCs, they are fire and explosion-proof, durable and environmentally friendly.

How to determine safe paintwork materials

The content of VOCs in coatings is currently not regulated in Russia, this information is not on the label and few manufacturers indicate this. In fact, the "safety certificate" is the Certificate of state registration Rospotrebnadzor, which can and should be required in the store. In accordance with the unified sanitary and epidemiological requirements for paintwork materials, the material is assessed for allergenicity and the ability to have an irritating effect. When these properties are identified, the manufacturer must place information on the label. Therefore, the label is one of the important criteria for determining the degree of safety of coatings. It must contain:

Name of material;

Purpose and method of application (this paragraph must be read very carefully, there you can get information about whether paintwork is suitable for you);

Basic consumer properties or characteristics of the material;

Rules and conditions for safe storage (including warning labeling), transportation, use and disposal of material;

Precautions when working with the material (even with the safest!);

Expiration date, batch number, release date; mass; compound;

Manufacturer's contact details (in case of imported products - additional contact details of the importer) - name, address, website, phone numbers.

Providing complete reliable information that meets the requirements of the legislation of the Russian Federation and the Customs Union (RF, Kazakhstan, Belarus) on the packaging facilitates the choice of products, and the availability of contacts makes it possible to obtain from the manufacturer / importer detailed information about a particular product. Knowing the name of the paintwork material, batch number and release date, you can always get information about whether this product was actually released by the manufacturer.

When choosing paintwork materials, it is quite difficult to navigate the range of materials offered, so a few recommendations below will help you make the right choice:

· Particular attention should be paid to the composition. For example, the more natural components (vegetable oils, resins, mineral pigments) and less organic solvents containing acetone, toluene, ethanol, butyl acetate, butanol and others, the safer the product.

· Pay attention to the VOC content of the paint, it is usually stated in grams per liter and may vary. In Russia, new standards for the permissible content of VOCs in paints will be regulated in technical regulations of the Customs Union "On the safety of paints and varnishes", which should come into force in September 2011. In the European Union paints for internal works are considered safe if the VOC content does not exceed 30 grams per litre. The main rule: the lower this indicator, the better.

· Choose paints of ready-made colors if possible, or ask the store to mix the desired shade for you. Thus, you will avoid the need to tint the paint yourself and once again you will not breathe in VOCs and pigments.

· Pay attention to related products: primers and fillers should also, if we are talking about safety, contain very little VOC.

· LKM should have a uniform consistency without a dense sediment. A sharp specific smell is a clear sign that the paintwork is unsafe.

Mandatory and desirable documents

The quality of the coatings can also be judged by accompanying documents which must be available from sellers. Their absence is a signal that the product may be dangerous. The following package is mandatory:

· Certificate of state registration of Rospotrebnadzor.

· Declarations of conformity in the GOST RF system - issued only for enamels, anti-corrosion primers and drying oils.

· Voluntary certificate of compliance with the requirements of 123-FZ "On Fire Safety Requirements".

· An important, although optional, criterion for the safety and quality of coatings is information on the label that the manufacturer has ISO 9001 quality certificates (standards for quality management and requirements for the organization of production) and / or ISO 14001 (environmental management).

· Voluntary certificate of conformity in the GOST RF system.

Operating conditions for safe coatings

Speaking about the security of paintwork materials, you need to understand that we are talking about relative security, not absolute. It is clear that during work it is necessary to observe not so much safety precautions as precautions, for example, keep away from children, as well as follow the rules for storage, transportation and disposal. All the necessary information is indicated in the text of the label, and more detailed information is in the accompanying documentation for the material, for example, in the safety data sheet.

But general measures The precautions are both simple and can be formulated like this:

Avoid contact with eyes;

Work in a ventilated area;

Keep paintwork materials out of the reach of children in a tightly closed package.

Anfisa Borisenko, Communications Director of Tikkurila, SBU East in collaboration with Tikkurila experts

The importance of wastewater treatment systems is undeniable. No building that is used by man can do without them. New ones are constantly emerging manufacturing enterprises, petrol stations, bars and restaurants, other service establishments, apartment buildings or country houses, and the problem of high-quality wastewater treatment remains relevant. To solve it, enterprises, local authorities, owners of residential real estate are building local treatment systems of various types.

The concept of VOC

Devices, structures, complexes of structures with various engineering communications and various combined systems, the main purpose of which is the complete or ultra-deep purification of household, industrial, rain and other sewage, are called local treatment facilities (VOCs).

Many equate VOCs with autonomous sewage - this is not true, since autonomous sewage is one of the types of VOCs that function independently and exist separately from the central sewer line.

Interesting to know. most main task What such structures, structures and their complexes should solve is the purification of wastewater to a level that is described in the legislative rules and regulations of the relevant services, which guarantees the absolute safety of the surrounding flora and fauna, the health and life of people.

VOC types

Local facilities for the purification of sewage water by location can be divided into the following types:

1. Treatment systems that are part of the municipal central sewerage system, which, after processing wastewater, send it to the city sewer network;
2. Cleaning systems that serve buildings or building complexes separately from the central sewer line, as they are removed at a decent distance from it or without the possibility of connecting to it (autonomous sewerage).

VOC of the centralized sewerage

The first group mainly consists of large-scale systems, which include whole line overall treatment facilities forming an automatic complex for the processing of large volumes of industrial effluents from factories, industrial production, plants and domestic effluents from cities, towns, and other settlements.

Such sewer systems are usually built outside the city line. The territory allocated for their construction and operation is a sanitary zone where it is forbidden to live and hold various recreational activities.

They are serviced by specially trained personnel, and they operate through special devices and equipment, control panels and automation systems.

Independent VOCs

Autonomous VOCs have smaller dimensions. Installed to purify industrial wastewater from small production organizations and factories, as well as effluents from economic activity person. They have a simpler design and cleaning technology with lower power and throughput.

Often, local sewage treatment systems of an autonomous type serve service industries, small villages and individual residential buildings that are far from the municipal sewage treatment network.

How does the LOS work?

The vast majority of local treatment facilities operate on a multi-level method of wastewater treatment, which consists in their passage of the following stages:

• mechanical (rough);
• bacterial (biological);
• chemical-physical.

Rough cleansing

Household and fecal water as a result of mechanical treatment is passed through various systems filters that trap large inclusions in them. The stage at which the effluents pass through the first filter system is called rough cleaning. After this stage, the wastewater passes the next set of filters, designed to remove smaller inclusions from the drains. Upon completion of the passage through the filters, the water enters specialized storage tanks, where the process of clarification takes place.

Chemical cleaning

Since wastewater is affected by various chemical reagents, inorganic and organic compounds that have a detrimental effect on the state of the environment, it is necessary to carry out the process of their chemical neutralization before discharging such water into a reservoir or river. This process is based on oxidation-reduction reactions. For example, if you want to get rid of impurities in the water caused by alkaline solutions, you need to treat the liquid with various acids, and vice versa.

Bacterial cleansing

This stage consists in the purification of wastewater from various organic contaminants by means of special bacteria, which, processing such contaminants, start the process of their decomposition with further removal from the VOC. This cleaning step can take place in an anoxic or oxygen environment, against which a distinction is made between anaerobic and aerobic cleaning.

Varieties of autonomous treatment systems

Autonomous local treatment systems include the following types of facilities:

• septic tanks with sedimentation tanks;
• biofilters;
• aerotanks.

These systems differ from each other in design features and the method of wastewater treatment.

Important! Any of the above facilities must necessarily be equipped with filtering installations or facilities, since on their own they will not be able to organize a full processing cycle, in which water will be purified by 97-100%.

Septic tanks

Constructions for organizing sewage, consisting of accumulation tanks, divided into chambers for cleaning and settling waste inclusions, are called septic tanks. They can include several storage tanks in their design. The most popular for organizing a sewer system in summer cottages and personal plots, as they have a low cost and a high level of practicality.

Septic tanks are small in size and contain all the necessary devices for organizing the processing of sewage water.

Such septic tanks are produced on an industrial scale mainly from high-strength plastic. This material is light in weight, which makes the installation of a septic tank quick and easy. Such systems perfectly withstand sharp temperature fluctuations, exposure to various aggressive environments, onslaughts and mechanical loads.

The construction of a septic tank can be carried out from concrete and other materials.

Note! Septic tanks are not able to treat wastewater by 100%, as they are part-cycle VOCs. Be sure to create special filter fields together with them, which contributes to almost complete soil purification.

On the market of local treatment systems, you can find ultra-deep cleaning stations, which are a kind of septic tank, where all kinds of filtering devices and other cleaning agents have already been installed. Such devices have compact dimensions and provide almost one hundred percent purification of sewage water.

Aerotanks

Specialized open storage tanks in the shape of a rectangle, where the filtration process and the sedimentation of abrasive fractions of wastewater are carried out, are called aerotanks.

Aerotanks have an elongated shape, reminiscent of water channels through which household and fecal liquid moves, mixing with activated sludge (a community of protozoa) with the help of air pressure, which is responsible for their processing.

Various substances appearing on the surface, for example, oil products, fatty inclusions, can also be removed in aeration tanks.

These structures do not exist in isolation, but are part of a complex of municipal sewer systems or, in a reduced form, are built into a septic tank with settling tanks and ultra-deep cleaning stations.

Design for biological treatment

Biofilters are special containers or structures that serve for deep purification of wastewater with the help of colonies of certain bacteria launched into them. Just like in aerotanks, they are part of municipal sewer systems or, in a reduced and simplified version, are built into septic tanks.

In addition to microorganisms, filter materials are placed in biofilters, which provide mechanical wastewater treatment, for example, expanded clay.

VOC for industrial enterprises

Local treatment facilities For industrial enterprises operate according to a progressive and more complex structure for processing wastewater with more complex pollution.

Treatment systems serving large or complex technological enterprises, in their structure contain:

• Mechanical cleaning line. The waste liquid enters the storage tank, from which it is distributed to biofilters, getting rid of large inclusions;
• Simultaneous processing of industrial effluents by the chemical method. After getting rid of large fractions, the effluent enters various settling tanks containing certain chemicals and solvents that bind to organic and inorganic water pollutants, forming feathers or lumps that settle at the bottom of the tank;
• Specialized greenhouses with aerotanks that contain activated sludge and water hyacinth, which rids the water of organic fractions;
• Biological ponds for post-treatment of wastewater, in which the last stage of work with fractions takes place by exposing them to special microorganisms;
• Disinfection station for sewage treatment by means of ultraviolet radiation.

Usually, each stage of processing industrial wastewater is carried out in a separate building or room, which makes it possible to avoid the release of polluting compounds or substances from these sewage effluents into the atmosphere, as well as to comfortably control the entire technological process.

VOCs in this structure provide processing of sewer lines at the following enterprises:

• poultry farms;
• meat processing plants;
• factories for the production of glass and other products from it;
• canning factories;
• car washes;
• factories of fat-containing products and vegetable oils;
• and other industrial enterprises.

VOC for rain (stormwater) runoff

Systems for the processing of storm water have their own characteristics in terms of structure and treatment methods, which is due to the presence in their composition of a significant content of suspensions of natural origin, chemical compounds and large particles.

These VOCs can successfully function for the treatment of storm water from the following facilities:

• car washes;
• factories;
• territories of industrial enterprises;
• large parking lots and car parks;
• adjacent territories to business centers and shopping facilities;
• household plot.

So a standard storm sewer system should contain the following elements:

• sump;
• trap of sand and other abrasive particles;
• trap of oil-containing substances (oil trap);
• absorbent filter;
• UV disinfection system;
• control container for approbation of the purified liquid.

VOCs for storm sewer systems have a high level of wastewater treatment (up to 98%) and productivity, as they must be ready to process a large volume of liquid, for example, during prolonged rains.

In the design of such sewer systems, there are sedimentation tanks, where effluents are separated from large fractions such as branches, street litter, glass, cobblestones and other particles washed up with water from melting snow or rain.

VOCs for storm drains must contain sand and oil traps in their system, as storm drains contain a large amount of abrasive substances and petroleum products emitted by cars and gas stations.

The final stage of purification of such effluents is their disinfection by means of ultraviolet rays, after which the purified liquid can be sent to natural reservoirs.

Local treatment facilities for sewage of any type provide those technological solutions that reliably provide high-quality wastewater treatment without negative impact on the state of the environment, making human life easier and more comfortable.

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