Wastewater treatment plant. Sewer collectors

2024 Author: Howard Calhoun | [email protected]. Last modified: 2023-12-17 10:16

Wastewater is one of the ills of the modern world. We produce so much sewage that in the absence of their treatment, half of the world would have every chance of turning into a real sewer. How is this problem solved? The answer is simple - treatment facilities for domestic wastewater. They allow you to turn liquid waste into a relatively safe technical liquid that can already be returned to natural ecosystems.

If runoff enters water bodies without treatment, the ecosystem is seriously damaged. To avoid this, several methods for their qualitative neutralization have been developed at once. Of course, the reserves of fresh water in our country are huge, but still they are not endless, and therefore one should constantly think about the renewal of this resource.

Why is wastewater treatment so important?

In recent years, there has been some growth in industry and the general standard of living of the population, and all these processes are directly related to the sharply increased volume of wastewater produced by industrial facilitiesand the national economy. That is why treatment facilities for domestic wastewater are becoming extremely important, since the ecological situation not only in our country, but throughout the world depends on them.

What causes the negative impact of wastewater on the environment?

The enormous harm caused by liquid household waste is largely due to the fact that they often enter natural reservoirs and other drains in a completely untreated, original form. They infect wells, other sources of fresh water for the population. Harm from effluents can be minimized only if they are settled at special facilities. If the treatment is insufficiently effective, then the bacteria and chemical compounds contained in the wastewater can cause irreparable harm to the environment and the he alth of animals, plants and humans.

Recycling of solid waste and legal regulations

Recycling of solid waste is widely practiced in many European countries. There, they began to be interested in this problem for a long time for one simple reason: in these states, the natural reserves of fresh water are significantly limited. However, in our country in recent years, a complete reuse of water has become increasingly common, due to which it is possible to significantly reduce the consumption of fresh liquid.

Many utility networks of large cities (especially those where the industry is seriously developed) have long been completely transferred to this technology. Operatortreatment facilities is obliged to constantly monitor the quality of cleaning, controlling the degree of contamination of the technical fluid by the remnants of pollutants.

Legislatively, all economic facilities are required to decontaminate the effluents they produce, using all possible mechanical and / or other methods for this. In addition, the law establishes rather strict measures and norms, which must be observed at the same time. Note that ordinary citizens are also responsible for this. It should be noted that the reconstruction of treatment facilities should be carried out on time, without any delays.

Household wastewater treatment

In recent years, many tools have been developed that allow for the full treatment of domestic wastewater, which is formed during the life of an average country house. It should be noted that waters of different origin are “sorted”, since the methods of their purification and decontamination differ significantly.

What are the methods of purification of solid waste and industrial effluents?

This includes a whole range of activities that allow you to effectively remove a wide variety of substances and compounds from a contaminated liquid. There are separate technologies for disinfecting wastewater from oil products, treatment facilities for household wastewater coming from livestock facilities, etc. Whichever technique is used, it belongs to one of the main types:

• Biological scheme.
• Mechanical cleaning (grids equipped with storm sewersstructures).
• Physico-chemical technique.
• Sewage disinfection method.

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

Mechanical method

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

• Devices like gratings or combs, which are most often equipped with mechanisms for self-cleaning. These are often equipped with sewers.
• Sand-catching elements.
• Membrane filters.
• First-order settling tanks.
• Septics.

The distance between the bars of the primary gratings should be no more than 16 millimeters, as they are used to screen out the coarsest and largest elements (they often fall into sewers). The waste received at this stage is either crushed or transported to the places where they are buried. Then comes the period of sand traps, which allow you to purify water not only from it, but also from small glass and other similar impurities.

They are no longer crushed or buried, but taken to long-term storage warehouses. The raw material that is thereaccumulated, subsequently used in the production of various road works. It is important to note that the cleaning of treatment facilities with a mechanical decontamination method should be carried out as regularly as possible, otherwise their efficiency drops sharply, trapping devices begin to pass too much contaminants.

The most promising method is wastewater treatment using membrane filters. This allows the waste to be deactivated to the extent that, in some cases, it can be recycled back into the production cycle. At the same time, it must be remembered that the mechanical method allows you to screen out no more than 70% of all types of contaminants, so treatment plants are not limited to it.

Biological technique

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

First, the water goes to the first-order settling tanks. There, the organic suspension is deposited, and the smallest particles are absorbed. In the secondary clarifiers, the accumulated sludge is removed using special pumps. In principle, almost every home garden can be equipped with such a system.plot.

So, today there are ready-made complex facilities for sale that allow biological and mechanical treatment of LRW. 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 purification has no smell and taste, it can be safely used for various household needs, including watering pets.

The most expensive and effective models include an ultraviolet wastewater disinfection unit. After such purification, water can be discharged even into natural reservoirs. The efficiency of liquid waste deactivation in such systems is at the level of industrial solutions.

Physico-chemical method

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

• Evaporation.
• Effluent treatment with ozonation.
• Introduction of chlorine compounds.
• Electroflotation.

Such methods are in great demand at the enterprises for the production of oil refining products, since extremely strict methods have been developed for them that control the effectiveness of the purification performed. In recent years, similar drainage systems are becoming more common in a private environment, for ordinary country houses. It is important to remember that it is strongly not recommended to apply such techniques uncontrollably in your area. The fact is that this technique uses quite a lot of chemicalsubstances that can cause significant harm to both your he alth and the he alth of pets and plants.

The most promising and effective under these conditions are the methods of cleaning liquid waste with the help of electrical impulses, as well as ultrasound and ultraviolet. There is only one drawback in this case - the very high cost of such equipment, which makes it inaccessible to many owners of suburban areas.

Wastewater disinfection

Before sending the purified liquid to natural reservoirs, it is required to carry out its complete disinfection and decontamination. For these purposes, in recent years, ultraviolet is most often used, but the use of "classical" chlorine is not excluded. It must be remembered that the operation of treatment facilities involves 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 being designed.

Important! When designing such structures, it is imperative to provide for the slightest possibility of flooding the site with groundwater and / or sewage. The treatment plant includes the following equipment:

• Devices for uniform distribution of wastewater (in particular, this is how stormwater treatment plants work).
• Devices that allow you to automatically remove excess contaminants fromcatching devices.
• Equipment that allows 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 waste water

To perform effective domestic wastewater treatment, the following conditions must be fully met:

• The right choice of technology to be used for this purpose.
• Choosing the most efficient equipment for the highest quality liquid purification from the widest range of contaminants.
• Absolute adherence to the technology recommended by the manufacturer.

Only with a responsible and economically viable approach to the choice of cleaning systems will they be appropriate. The higher the degree of wastewater decontamination, 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 regard, as they fully meet several important conditions at once:

• High versatility, thanks to which these water treatment plants are able to retain almost all types of contaminants.
• Their efficiency reaches 99.5%.
• Small footprint and low maintenance cost.
• Easy assembly and installabilityadditional modules that allow you to significantly expand the functionality of the installation.

About collectors

Any project 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 can flow down them by gravity. The urban sewer networks have the following hierarchy:

• Yard and block plots, the diameter of which is 150-200 mm. Their peculiarity is that when laying these structures, they are never taken outside the streets.
• Street-type collectors, their diameter is 250-400 mm. On the contrary, they are being built on the territory of the streets, and in some cases they can be equipped with compact pumping stations.
• Regional collectors. Their diameter can be about 500-1000 mm. They are being built for entire urban areas and equipped with pumping stations without fail.
• Collectors of urban importance. Diameter - 1000-5000 mm. They are being built along the perimeter of the city in the most low-lying areas.

Throughout the sewer network manholes must be built from reinforced concrete rings with a diameter of 1 meter (their depth is up to six meters). In some cases, one and a half 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, during the construction of a yard sewernetworks with a collector diameter of 150-200 mm, the step between them should not be more:

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

We hope you found the information in this article helpful.