Industrial sewerage: how to clean. Domestic waste water treatment methods Sewage water treatment
Cleaning Wastewater sewers this is a set of mandatory activities. Its implementation is regulated by current legislation and which is necessary both for the purpose of protecting the environment and for the renewal of water resources. Modern technologies cleaning with the use of methods of different nature allows you to ensure the maximum purity of the liquid returned to nature.
Photos of objects
Objects on the map
Video of the company "PROMSTROY"
View other videos
What is meant by sewage wastewater?
It is customary to call sewage wastewater:
- all liquid waste from human life and activities, the so-called domestic wastewater;
- industrial waste water, water used directly in production, as well as for cooling systems;
- atmospheric precipitation that enters the sewer through the storm sewer system.
By types of pollution, waste is classified as follows:
- Mineral containing:
- salt;
- sand;
- clay, etc.
- chemical organics;
- polymers.
As a rule, sewage drains are a combination of all types of pollution, which makes it necessary to carry out their multi-stage purification.
Sewerage wastewater treatment cost
| Name of service | Price |
| Maintenance of substations (independent scheme) | from 6,000 rubles / month |
| Maintenance of heating points (dependent scheme) | from 10,000 rubles / month |
| Maintenance UUTE | from 3000 rubles / month |
| Installation UUTE | from 250,000 rubles |
| Hydraulic tests (pressure testing) | from 7,000 rubles |
| Heat exchanger chemical cleaning | from 8,000 rubles |
What methods are used for sewage treatment?
A variety of contaminants makes it necessary to purify sewage wastewater according to a combined scheme using the following methods.
- Mechanical.
It is used to remove large particles and insoluble residues and serves preparatory stage for subsequent biological cleaning.
Sorting of this group of waste can be done in such ways as:
- straining;
- filtration;
- upholding;
- centrifugal filtration.
The combination of these methods used in practice can significantly increase the efficiency of mechanical cleaning.
This method is used, as a rule, for the treatment of industrial wastewater and consists in the addition of chemical reagents that help transform soluble components into insoluble ones for their subsequent removal by a mechanical method.
The action of the reagents can also be directed to such reactions as:
- neutralization;
- oxidation;
- recovery.
In practice, due to its high cost, chemical method in its pure form is used extremely rarely.
Being a combination of the use of physical and chemical properties liquids and microelements, this group methods are considered the most effective for treating a wide range of wastewater, including industrial waste.
There are the following cleaning methods:
- electrochemical;
- coagulation;
- sorption;
- ion exchange;
- extraction, etc.
It should be noted that the complex application of the physicochemical method makes it possible not only to obtain an almost pure liquid at the outlet, but also to fully automate the entire process.
These cleaning methods are based on special bacteria capable of processing human waste products with a liquid purity level of up to 95% at the outlet.
By types of bacteria can be:
- aerobic, which requires air to live;
- anaerobic, living without oxygen.
The use of bacteria is considered the most promising direction in the purification of polluted effluents, but this method is not acceptable for processing industrial effluents.
However, in the residential sector and in the urban economy, this method is widely used.
It is used in the case when liquid purification is impossible, as well as for liquid waste immediately after carrying out the corresponding processes. The essence of the method consists in spraying contaminated liquid over a burning fuel torch.
Calculate the cost of sewage wastewater treatment for you
To select the optimal treatment method, sewage drains in a specific area are thoroughly analyzed to determine their composition, on the basis of which the most effective combination of methods is developed.
The purification processes themselves take place at specialized stations, which are a complex system of tanks, sedimentation tanks, filtration modules, etc. The composition of the equipment is also determined by the composition of specific waste.
Thus, sewage treatment is a process that involves the use of a variety of methods and technologies. The general decline in water resources increases the importance of this area, and government regulation is an additional incentive for improving technologies in this area.
A sewage system in the absence of a centralized system is a complex engineering task. The sewerage scheme is determined by the type of equipment for the toilet, the total volume of "gray" wastewater from washbasins, bathtubs, washing machines, swimming pools. As well as the geological features of the area: the depth groundwater, filtering capacity of soils, the presence of water intakes in the immediate vicinity of treatment facilities.
Wastewater entering the sewer network may contain wastes of mineral origin (sand, clay, slag particles, salts, acids, alkalis dissolved in water); decaying organic matter (animal and plant origin); pathogenic bacteria, harmful chemicals. Wastewater treatment methods used in local sewerage systems can be divided into three main types: mechanical, chemical and biological.
Chemical cleaning method wastewater is based on the use of various reagents that convert dissolved impurities into a poorly soluble state. Further, the deposition of these substances occurs. This method is mainly used for the treatment of industrial wastewater.
Mechanical cleaning consists in removing from the waste liquid wastes of mineral origin, which are in it in an undissolved, and partially in suspension, as well as from foreign objects floating in sewage. When using a mechanical treatment method, wastewater settling and filtration occurs. One of the disadvantages of this method is that the water is not purified from dissolved organic contaminants. Therefore, mechanical treatment facilities (sedimentation tanks, sand traps, grates and sieves) are most often a preliminary stage before biological treatment.
V biological treatment waste water involves bacteria, which, depending on their relationship to oxygen, are divided into two groups: aerobes (using oxygen dissolved in water during their breathing) and anaerobes (developing in the absence of free oxygen).
Anaerobic (no air access) cleaning carried out in closed containers (digester tanks, septic tanks, two-tiered sedimentation tanks), where organic pollutants are fermented with the help of methane-forming anaerobic bacteria.
At aerobic (with air supply) cleaning drainage fields, filtering wells, biological filters and aeration tanks are used, in which the purification process takes place intensively. Oxygen, necessary for the life of microorganisms, comes from the ambient air or is pumped in with special compressors (blowers). A large amount of organic substances contained in wastewater serves as a favorable breeding ground for aerobic bacteria, which are able to absorb various organic substances in the course of their life. During biological treatment, activated sludge is created. Sewage effluent is mixed with activated sludge, significantly accelerating and improving the oxidation process. As a result, pathogenic microbes are absorbed by activated sludge, die or become its active agents or their decay into harmless ones. Thanks to this, the water loses its tendency to decay, becomes transparent, and its bacterial contamination is reduced.
In modern biological treatment plants, both types of bacteria are used: anaerobes and aerobes. At first sewer drain enters a container with anaerobes and is oxidized there for 2-3 days, then it undergoes a post-treatment process in containers with aerobes or in natural conditions. The waste liquid during biological treatment is almost completely freed from organic matter and harmful bacteria.
Rice. 24. Dry closet
For a summer house, you can choose a cheaper option: arrange a cleaning to drain gray water from sinks and showers and use a dry closet (Fig. 24). This is an intermediate option for those who do not want to install an expensive sewerage system and at the same time want the "latrine" to be more convenient than the "outhouse" - a backlash or powder closet.
"Engineering Equipment" offers equipment for the treatment and pumping of domestic, storm, industrial waste water. The scope of work includes design, production, supply and installation of a wastewater treatment system. The main advantage of our company is complex turnkey works for the organization of wastewater treatment.
In Engineering Equipment, you can not only buy wastewater treatment plants for your home or business. The price for underground or above-ground local installations depends on the complexity of the project. Detailed information can be obtained by calling 8-800-500-31-02.
The best domestic wastewater treatment plants!
"Tver". Highly efficient and reliable domestic waste water treatment plant. The equipment is designed for deep mechanical and biological treatment, a wide range of the lineup, the system is selected according to the customer's requirements.
"Swir". Modern installation for the treatment of melt and storm water effluents. The scope of the equipment is the residential sector, gas stations, industrial facilities, etc. The system performs complex filtration from various contaminants.
Grease traps. The elements of the wastewater treatment plant prevent oil and grease from entering the sewage system. The equipment is perfect for use in catering establishments and food industry facilities.
"Sviyaga". Provides recycling water supply. Effectively cleanse water from impurities in car washes. Filtered liquid can actually be reused, which significantly reduces utility costs.
"Tver-S", "Svir-S". Sewage treatment plants at low temperatures... The units cope with high loads and operate smoothly, regardless of the climate.
High reliability of the system is achieved through the use of high-quality imported equipment.
"Desis". Reliable plant for the disinfection of infected effluents. It is widely used in tuberculosis dispensaries and medical institutions where infectious diseases are treated. Suitable for other similar objects.
"Engineering equipment" - turnkey work of any complexity!
- Design - the specialists of the technical department will carry out the design of the facility in a short time.
- Plant production - our company's specialists will manufacture a treatment plant for a specific object.
- Delivery to the customer - fast delivery of finished equipment to anywhere in Russia.
- Professional installation - experienced specialists are engaged in the installation of wastewater treatment systems. On account of the masters of hundreds of successful projects!
- Start-up and commissioning - putting the system into operation and performing the necessary tests.
Wastewater treatment is an indispensable process, as it makes sewage waste safe for people and the environment. Today, technological progress negatively affects the water resources of our planet, so every drop counts. For this reason, treatment methods have been developed that help reuse wastewater for irrigation of land or simply recharge the soil. In today's article, we will discuss with you the main methods of filtering sewage fluid.
First, let's find out what belongs to the concept of wastewater? For this understanding, it is customary to take all the liquid with and without impurities, which is drained into the sewer system. An important characteristic is the presence of contamination obtained in a particular field of application. It is worth considering that the liquid of atmospheric precipitation is also read in here.
Types of contamination
Wastewater treatment is a process that takes place with the correct selection of equipment. It is worth considering that its important component is compliance with a certain type of pollution. For this reason, let's find out their types that can be found in waste water:
- Mineral contamination... This type includes all inorganic components, such as: salt, earth, etc.
- Organic matter... It is a sewage fluid containing the remains of the world of flora and fauna. Their composition is usually composed of chemical organics and polymers.
- Biological components... They are represented by bacteria and various other microorganisms.
Attention! In most cases, a sewer drain has all three components. If it is domestic wastewater, then organic matter will treat minerals as 3 to 2. As for bioorganisms, their number depends on the environment.
Cleaning standards
Any water treatment plant must fulfill a certain level of recycling. It is worth noting that the regulated strict norms are prescribed only for the industrial sector. In addition, the ratio of each type of impurity is fixed by law. For example, iron after processing should be present in an amount of no more than 0.1 mg per liter.
In relation to household drains, there are softer requirements. But this is not a reason to relax. One of the most important rules for managing wastewater in a private area is that untreated wastewater cannot enter the environment... For violation of this regulation, the owner of the house will be held administratively liable.
Important! Today, the state regulates only the maximum possible amount of impurities in water. At the moment - this only applies to the discharge into the reservoir. But remember that checking can make these claims in relation to the discharge of runoff into the soil.
Wastewater treatment methods
Based on a variety of filtration and wastewater treatment methods, today they can be divided into types. Namely, there are two types of wastewater treatment methods:
- Destructive species;
- Recuperative methods.
For the first characteristic feature there is a process of dividing wastewater into simple components, which in the future can be easily discharged, for example, in the form of gas. The second types select all valuable substances from the sewage fluid in order to process them in the future.
The cleaning process - how to do it
Technological progress does not stand still, and therefore every day there are new ideas and ways to clean the drains. After all, do not forget that this is an additional water resource. In this section, we will get acquainted with each of the types separately, but first, let's list them:
- Mechanical;
- Biological;
- Physicochemical;
- Disinfection method;
- Thermal disposal.
Let's consider in detail the methods of wastewater treatment.
Mechanical method
This is one of the simplest options. The process itself includes the removal of all components from the effluent that do not dissolve. What are these components? First of all, these include solids and grease. Sewage water is passed through a sieve and a sump, which is then passed only by liquid with small particles.
The most the best option mechanical treatment of sewage water is considered a membrane method. Its main feature is nothing more than the best cleansing process. The main thing is not to forget that this type of filtration gives a result of 70% and is the start for the biological method.
Biological cleaning process
Wastewater treatment with biological substances is carried out using the functioning of bacteria and microorganisms in the system. Their main feature is the ability to oxidize solid particles. The basis for the creation of this method was the microflora of natural water sources. Studies have shown that wastewater gets rid of nitrogen and phosphorus, which are harmful to the environment. Bacteria are of the following types:
- Anaerobic microorganisms that can function without air;
- Aerobic types cannot work without oxygen.
If cleaning is carried out with the help of air, that is, with aerobic bacteria, then it is possible to install a biofilter or aeration tank. These structures have a high purification efficiency and can fight activated sludge. With anaerobic microorganisms, a fermentation process takes place, which converts organic matter into methane and carbon dioxide.
With such cleaning, biofilters and aeration tanks with activated sludge are used. They are highly purified and more efficient than biofilters for wastewater treatment. Aeration of water and its deep biological treatment are carried out in aeration tanks. In addition, the result is activated sludge, which is a good fertilizer. Anaerobic wastewater treatment is carried out without oxygen. When exposed to anaerobic bacteria, the process of fermentation and the transformation of organic matter into methane and carbon dioxide occurs. It is worth noting that the second method is slightly cheaper.
Attention! In modern devices, two types of microorganisms are used, which can be easily used even in industrial sewers.
Physicochemical method
These wastewater treatment methods are very effective and are based on the teachings of the sciences of chemistry and physics. These types include:
- Electrolysis is a very popular method for industrial enterprises... The basis of the treatment process involves the destruction of organic constituents of water to obtain inorganics.
- Coagulation is water purification, which is carried out when components stick together under the action of forces. The result of the process is the formation of an aggregate.
- Precipitation of metal hydroxide flakes- this action is the result of the influence of coagulants, which cause a precipitate to form. The formed flakes are used for wastewater treatment.
The physicochemical process has a large number of advantages, for example, the removal of toxins and impurities that are not able to oxidize. It is also worth adding that this method provides a very high percentage of purification. This method can easily automate the dimensions of filtration structures, which will reduce the sensitivity of the action.
Disinfection
This method is reproduced by means of exposure ultraviolet rays, chlorine or ozone. Typically, the method is used to decontaminate water before being discharged into a body of water. The most effective process is considered to be with the use of rays, since it is safe. It is worth considering that their effect can have a detrimental effect on bacteria and various viral microbes.
The type of cleaning based on chlorination implies the disinfection of all microorganisms with chlorine. The main disadvantage of this mechanism is the creation of toxins and carcinogenic compounds. It is for this reason that you should be very careful when applying this method.
Ozonation is ozone treatment. Everyone knows that this is a type of gas that contains three oxygen molecules, thereby forming a powerful oxidizing agent that kills microbes. It is important to say that this method is very expensive, therefore it is very rarely used in everyday life. The main sphere of its use is manifested in the production of industrial sectors.
Thermal disposal
Heat treatment of sewage effluents is carried out in situations where other methods do not give results. The principle of operation is to spray liquid into a combustion fuel flare. This is very effective method, but due to its price and volume, it is found mainly in production.
Attention! Modern treatment facilities perform the process in several steps, therefore, very often the use of several methods is programmed in them.
So, the process of purifying sewage water is required condition operation of the wastewater disposal system. It should not be overlooked that these requirements are regulated by sanitary and legal norms.
Waste water, formed in the process of human activity, entering water bodies, becomes one of the most serious sources of pollution that negatively affects human health. To reduce the pollution of water bodies, a set of measures is applied to cleaning upWastewater- removal of contamination from them. Runoffs, depending on their origin, are divided into the following types:
- Domestic or household fecal, which include receipts from residential buildings and public buildings;
- Industrial - generated in technological processes and taken away from the territories of industrial enterprises;
- Rainfall collected during rainfall, snow melting and cleaning of territories.
Households are contaminated with all kinds of organic impurities, including food debris, and carry a huge amount of bacteria, both neutral and pathogenic. The main task of processing such effluents is to extract large and small inclusions, oxidize the organic matter contained in them, in order to reduce the load on the environment and disinfect.
Industrial effluents, also depending on the nature of their formation, can contain a variety of organic ingredients, for example, dairy effluent, mineral inclusions and other compounds harmful to life. Liquid waste generated at metalworking enterprises contains metals, including heavy metals, which, if ingested, can have a negative effect on human health.
Storm runoffs wash away organic impurities, suspended particles (sand, clay, etc.) and oil products from the territories.
The effluent is of various origins and contains a variety of pollutants. The discharge of rainwater into water bodies without treatment leads to their serious pollution, adversely affects human health, can accumulate in the inhabitants (fish) and, accordingly, get into the body with food.
For cleaning use different ways, which depend on the nature of the formation of liquids, their composition and quantity. Consider the methods of processing household water, tk. they make up the largest part drains.
Domestic wastewater treatment methods
Wastewater entering the treatment plant goes through several stages of processing:
- mechanical;
- biological;
- disinfection.
For the mechanical stage, the following equipment is used: grates, sand traps, sedimentation tanks, filters. The first structure to which the drains fall is the grates. They are a set of rods installed vertically or with an inclination on which large inclusions are delayed. The recommended gap between the rods is 16 mm. Detained debris from the grates is removed manually (for small stations) or using a mechanical rake. The collected waste is collected in a special container, then taken to a landfill.
For the mechanical stage, the following equipment is used: grids, sand traps, sedimentation tanks, filters The next stage is settling in sand traps, which are rectangular or round in terms of structures. When entering the sand trap, the speed of movement decreases, and heavy ingredients, mainly of mineral origin (sand), settle. These particles carry all the pollutants. The sand settles to the bottom of the sand trap, is moved by scrapers or washed into the lower part into the pit, then by pumps or water-jet devices it is removed to the sand platform. After drying, the sand must be decontaminated and can be used, including for planning work.
After preliminary purification, the water enters the primary sedimentation tanks, which, depending on the direction of movement in them, are divided into horizontal, radial and vertical. The choice is determined by the performance of the structures. With low productivity, vertical ones can be used, with medium - horizontal ones, for large stations they use radial ones. The principle of operation of sedimentation tanks is the same - when the speed of movement decreases, impurities of various sizes are released. The speed of movement in the settling facilities is determined regulatory documents... The impurities settle to the bottom, then by scrapers, liquid jets or under the influence of their own weight, they move to the pits, then are pumped over for further processing. There are various methods for intensifying sedimentation, first of all, this is reagent treatment, when chemicals are added that contribute to the coarsening of suspended particles. Larger particles settle faster. Another method is thin-layer sedimentation, when a set of shelves is placed in the sump and the process goes faster, due to a decrease in the settling height.
Secondary sedimentation tanks belong to the structures of mechanical cleaning, but are located after the stage of biological treatment, which we will consider in the next section. Secondary, as well as primary, are subdivided into horizontal, radial and vertical, but it is not suspended substances that are released in them, but activated sludge, which is formed in aeration tanks or biofilters.
The next stage is settling in sand traps, which are rectangular or round in terms of structures. Filtration is used for deep post-treatment of impurities. This process completes the technological scheme and is used in cases of stringent requirements for the quality of runoff discharged into water bodies. Post-treatment is performed on filters of different designs, the choice of which depends on the performance of structures and pollution. Filtration is carried out through various loads, mainly natural materials of various sizes, the most popular of which is quartz sand.
Biological treatment
The settled effluents enter the aerotanks - biological oxidation units. In aeration tanks, water is mixed with activated sludge - flocculent compounds of bacteria, and air is supplied here in the form of small bubbles. In the presence of air, bacteria actively absorb organic ingredients, they are oxidized and the amount of activated sludge increases. The mixture flows into the secondary settling tank, where the sludge settles, then part of the sludge is removed for processing, and part is returned to the aeration tank. At low productivity, instead of aeration tanks, biofilters are used - tower-type structures filled with a special load and ventilated from below. The bacteria settle on the boot. The liquid, moving from top to bottom through the load, comes into contact with bacteria in the presence of air and is intensively cleaned.
Purified liquids contain a large number of bacteria, including pathogenic ones, therefore, they must be disinfected before being discharged into a reservoir. For disinfection are used:
- sanitation with chlorine-containing reagents;
- ozonation;
- ultraviolet irradiation.
Each method has its own advantages and disadvantages. Chlorination involves the use of chlorine, a toxic substance, therefore, work with it requires special care. The liquid after chlorination must be kept for at least half an hour to remove chlorine compounds. For this, contact tanks are used.
Purified liquids contain a large number of bacteria, including pathogenic ones, so they must be decontaminated before being discharged into a reservoir. Such reservoirs, with high productivity, occupy significant areas. Ozonation is an expensive, energy-intensive procedure and is carried out in sealed structures. UV disinfection is limited in performance.
During the processing of domestic wastewater, primary sediment is released in the primary sedimentation tanks, after the aeration tanks, activated sludge is released in the secondary sedimentation tanks.
Recycling and subsequent disposal of the resulting sludge is one of the most serious tasks of the sewerage system. The complexity of the problem is determined by their large volume and properties. As a rule, sediments are hard-to-filter suspensions of organic origin. Their volume, depending on the composition and technological scheme, is 0.5 - 10% of the flow rate supplied to the treatment facilities. Their moisture content is 90 - 99%, most of the moisture is in a bound state. The bacteria and helminths contained in them require serious decontamination before further use.
Recycling and subsequent disposal of the resulting sludge is one of the most serious tasks of the sewerage system. The main tasks are moisture reduction, stabilization, and disinfection.
Methane digestion and aerobic stabilization are used to convert the main part of organic matter into a mineral form. Methane digestion is carried out in digesters, where, under the influence of high temperature sediment mineralization occurs, while gas is released - methane, which can also be used at treatment facilities for their own needs. The difficulty lies in the contamination of the gas with impurities. During fermentation, in addition to mineralization, the issue of disinfection is resolved.
Aerobic stabilization is used to mineralize active or. The process is an active aeration of sludge in structures similar to aeration tanks. The next stage in the processing of sludge is their dehydration. For dehydration, natural methods are used (drying on sludge platforms) and mechanical (on belt or chamber filter presses, centrifuges, vacuum filters). Before dehydration, to transfer moisture from a bound form to a free one, it is treated with reagents or flocculants. Dehydrated sludge with a moisture content of 70 - 80% (depending on the method of dehydration) is fed for further processing - disinfection - mainly by thermal methods.
After disinfection, the sludge is suitable for use as a valuable fertilizer.
Wastewater treatment plant