Wastewater treatment plants of domestic sewage. Sewer collectors

Sewage is one of the troubles of the modern world. We produce so many wastewater that, in the absence of their treatment, half of the world would have a chance to turn into a real sewage system. How is this problem solved? The answer is simple - treatment facilities of domestic sewage. They make it possible to convert liquid waste into a relatively safe technical fluid that can already be returned to natural ecosystems.

If the effluents enter the water bodies without treatment, the ecosystem is seriously harmed. To avoid this, several methods for their qualitative neutralization have been developed. Of course, the reserves of fresh water in our country are huge, but they are not endless forever, and therefore we must constantly think about the renewal of this resource.

Why is sewage cleaning so important?

In recent years, there has been some growth in industry and the general standard of living of the population, all of which are directly related to the sharply increased amount of sewage that are produced by industrial and economic facilities. Therefore, treatment facilities of domestic sewage become extremely important, since it is the ecological situation that affects them not only in our country, but all over the world.

What is the cause of the negative impact of runoff on the environment?

The huge harm caused by liquid household waste is largely due to the fact that they often enter natural water bodies and other drains in a completely uncleaned, original form. They are infected with wells, other sources of fresh water for the population. The damage from effluents can be minimized only in case of settling them at special facilities. If the cleaning is performed with insufficient efficiency, then the bacteria and chemical compounds contained in the effluents can cause irreparable harm to the environment and the health of animals, plants and humans.

Processing of nuclear waste and legislation

The processing of iron ore is widely practiced in many countries of Europe. There, this problem began to be interested in quite a long time for one simple reason: in these states, the natural reserves of fresh water are substantially limited. However, in our country in recent years, a full recurrence of the use of water has become increasingly widespread, as a result of which it is possible to substantially reduce the consumption of fresh liquid.

Many utilities of large cities (especially those with a seriously developed industry) have long been completely transferred to this technology. The operator of treatment plants must constantly monitor the quality of cleaning, monitoring the degree of contamination of the technical fluid with residues of pollutants.

Legislatively, all economic entities are obliged to decontaminate the sewage produced by them, using for this purpose all possible mechanical and / or other methods. In addition, the law establishes fairly stringent measures and norms, which must be observed at the same time. Let's notice, that for it ordinary citizens answer also. It should be noted that the reconstruction of sewage treatment plants should be carried out on time, without any delay.

Wastewater treatment

In recent years, many tools have been developed that allow full-fledged treatment of domestic wastewater generated by the life of an average country house. Note that waters of different origin are "sorted", since the methods for their cleaning and decontamination differ significantly.

What methods exist for cleaning ZHBO and industrial wastewater?

This includes a whole range of activities that can effectively remove a variety of substances and compounds from the contaminated liquid. There are separate technologies for disinfection of effluent from oil refining products, sewage treatment plants for domestic sewage coming from livestock facilities, etc. Whichever method is used, it refers to one of the main types:

• The biological scheme.
• Mechanical cleaning (grids with which storm water treatment facilities are equipped).
• Physicochemical methods.
• Method of disinfecting wastewater.

Let's look at each of these methods in more detail.

Mechanical method

All wastewater treatment plants of household sewage use this method, since the liquid before entering the departments of finer processing must necessarily be freed from large mechanical particles that contaminate it. In addition, this method is used to remove water from the sludge obtained as a result of other stages of wastewater treatment. The following elements can be used for this purpose:

• Devices like grids or combs, which are often equipped with mechanisms for self-cleaning. These are often equipped with sewage collectors.
• Sand trapping elements.
• Membrane filters.
• Sediment tanks of the first order.
• Septic tanks.

Between the bars of the primary gratings, the distance should be no more than 16 millimeters, as they are used to screen out the coarsest and largest elements (they often fall into the sewer collectors). The wastes received at this stage are either crushed or exported to the places where they are buried. Next comes a period of sand catchers, which allow you to clean water not only from it, but also from small glass and other similar impurities.

They are no longer crushed and buried, but transported to warehouses of long-term storage. The raw materials that are accumulated there are subsequently used for various roadworks. It is important to note that cleaning of treatment plants with a mechanical deactivation method should be carried out as regularly as possible, as otherwise their efficiency drops sharply, the trapping devices start to transmit too much contaminants.

The most promising technique is the treatment of effluents using membrane filters. This allows you to deactivate the waste to such an extent that in some cases they can be returned back to the production cycle. At the same time, it should be remembered that the mechanical method allows to filter out no more than 70% of all types of contaminants, so that the sewage treatment plants are not limited to them only.

Biological methods

Virtually any wastewater is contaminated by various types of microscopic organisms. With a biological technique, nitrogen and phosphorus, as well as anaerobic and aerobic bacteria, can be removed from the effluent. Very often, this technique uses the technology of biological fermentation, activated sludge, as well as fine biological cleaning filters. How do biological sewage treatment plants work?

First, the water goes to the first-order sedimentation tanks. There, the organic suspension is precipitated, and the finest particles are absorbed. In the secondary settling tanks, the accumulated sludge is removed by means of special pumps. In principle, such a system can be equipped with almost every homestead suburban area.

So, for today on sale there are ready complex constructions which allow to make biological and mechanical clearing ZHBO. Their main value lies in the ease of operation and the absence of the need for frequent maintenance. Water after passing through the system of such cleaning has no smell and taste, it can be safely used for various household needs, including the drinking of domestic animals.

The most expensive and effective models include a block of ultraviolet disinfection of waste water. After such cleaning, the water can be completely discharged even into natural water bodies. The effectiveness of the deactivation of ZHBO in such systems is at the level of industrial solutions.

Physicochemical method

In this case, a combined technology is used, which includes the following methods:

• Evaporation.
• Treatment of waste water by ozonation.
• Introduction of chlorine compounds.
• Electrofloatation.

Such methods are very in demand at the enterprises for the production of oil refining products, since extremely stringent methods have been developed for them, which control the efficiency of the produced cleaning. In recent years, similar systems of water disposal are becoming increasingly common in a private environment, for ordinary country houses. It is important to remember that it is strongly recommended not to apply these methods uncontrolled in your own area. The fact is that this method uses a lot of chemicals that can cause significant harm to your health, as well as the health of pets and plants.

The most promising and effective in these conditions have shown themselves methods of cleaning ZHBO using electric pulses, as well as ultrasound and ultraviolet. The drawback in this case is only one - very high cost of such equipment, which makes it inaccessible for many owners of suburban areas.

Disinfection of waste water

Before sending the purified liquid to natural reservoirs, it is required to conduct its complete disinfection and decontamination. For these purposes in recent years, most commonly used ultraviolet, but it is possible and the use of "classical" chlorine. It should be remembered that the operation of treatment facilities implies their location on the leeward side of any housing or settlement. In addition, the site for their placement must necessarily have a slope, due to which the drains will be removed naturally, without the need to install special pumps. This is especially important when urban wastewater systems are designed.

Important! When designing such structures, it is necessary to provide for the slightest possibility of flooding the site with ground and / or sewage. The treatment facilities include the following equipment:

• Devices for an even distribution of wastewater (in particular, so work storm water treatment facilities).
• Adaptations that allow automatic self-removal of excess contaminants from trapping devices.
• Equipment that allows the emergency discharge of excess sewage.
• Instruments that measure the physical and chemical characteristics of effluents and their precipitation.
• If necessary, installations that perform automatic sampling can be used.

Disinfection of domestic sewage

To carry out effective treatment of domestic wastewater, the following conditions must be fully met:

• The right choice of technology that will be used for this purpose.
• Selection of the most effective equipment for the highest quality purification of liquids from the widest range of contaminants.
• Absolute compliance with the manufacturer's recommended technology.

Only with a responsible and economically viable approach to the selection of purification systems will they be appropriate. The higher the degree of decontamination of effluents, the more fully they can be reused in production, significantly saving the company's funds. Flotation and membrane filters proved to be the most attractive in this respect, since they fully meet several important conditions:

• High versatility, thanks to which these water treatment facilities are able to withstand almost all types of pollution.
• Their effectiveness reaches 99.5%.
• Small space required for installation and low maintenance costs.
• Easy installation and the ability to install additional modules, which can significantly expand the functionality of the installation.

About collectors

Any design of outdoor treatment facilities must necessarily comply with SNiP 2.04.03-85. The basic principle of their laying is hierarchical: all small networks are connected to larger collectors. If possible, the pipes are laid in such a way that the liquid along them can flow by gravity. In urban sewer networks, the hierarchy is as follows:

• Yard and quarter sections, the diameter of which is 150-200 mm. Their peculiarity is that they are never removed from the streets when building these structures.
• Collectors of street type, their diameter is 250-400 mm. On the contrary, they are just built on the streets, and in some cases they can be equipped with compact pumping stations.
• District collectors. Their diameter can be of the order of 500-1000 mm. They are built for entire urban areas and are compulsorily equipped with pumping stations.
• Collectors of urban importance. The diameter is 1000-5000 mm. Are built along the perimeter of the city in the most lowered areas.

Throughout the sewage network, inspection wells of reinforced concrete rings with a diameter of 1 meter are always constructed (their depth is up to six meters). In some cases, 1.5-meter rings are used, the depth of the well under this condition is up to six meters. Their step is calculated according to SNiP 2.04.03-85. For example, when building a yard sewer network with a diameter of 150-200 mm, the distance between them should not be greater:

• At 150 mm - 35 meters.
• More than 150 mm - 50 meters.

We hope that the information obtained from this article was useful to you.