Stormwater treatment facilities: technology and methods for treating stormwater

Not all people think about how everyone needs storm water treatment plants, are not familiar with the varieties and features. But in vain. Due to the improper arrangement of these systems, people suffer not so much from villages as city dwellers.
Storm sewers are used to collect liquids - rainwater and water that forms when snow and ice melt. Roads and streets in rainy times and floods are filled with water collected in the storm sewer system.

The principle of operation of storm sewer treatment plants

But the operation of the system is not simply to collect liquid. Collected water must be treated before disposal. Harmful substances must be removed from it:

1. Residues of fuel and oils used by road transport.
2. Chemical reagents that are used to combat ice.
3. Ordinary trash.

Features of cleaning storm drains.

All these tasks should be performed by stormwater treatment plants. Thanks to them, cleanliness is ensured in cities and towns, and the bowels of nature are protected from the harm of substances that may contain storm drains.

How can storm drains be cleaned?

To qualitatively purify wastewater that comes from storm sewers, you can use three methods:

Mechanical. It is carried out by special sand-trapping elements capable of retaining large and insoluble parts of waste. Sand-trapping elements are installed at the inlets of the cleaning devices.

Physico-mechanical. Through the use of this method, petrochemical products are isolated. For this, a centrifuge and adsorption filters are installed.

Chemical. In this way, especially dangerous substances are neutralized. It is used most often for oil refineries and chemical plants.

It is probably clear that the greatest effect can be achieved by using all cleaning methods simultaneously.

Industrial methods of wastewater treatment.

Ordinary and storm drains differ in that the former are received regularly, while the latter are irregular. A large amount of storm water is formed when the snow begins to melt in the spring, and in the summer and autumn seasons - when prolonged and heavy precipitation occurs. And only in winter, storm water is almost not formed. The only exceptions are snow masses removed from the streets of the city by public utilities.

Devices used to treat storm water

To understand the principle of operation of devices used to treat storm water, a detailed consideration of their design is necessary. Storm sewer consists of:

1. Tanks in which the redistribution of water flows occurs;
2. reserve capacity;
3. Sand traps;
4. Oil trap;
5. A filter that cleans by sorption;
6. Revision well.

Tanks redistributing the water flow

This container serves to distribute wastewater that enters the storm sewer during mass discharge. It is impossible to do without it during periods when nature “spoils” people with heavy rains. If this element of the treatment plant is operating normally (this happens when the level of runoff is constant and insignificant), then it directs all rainwater through the collector to the treatment system.

If the water level greatly exceeds the allowable limit, the excess water must go to the clean water discharge point, which will not harm the treatment, because when rainwater enters in bulk, it has a small degree of pollution.

If excess water is not drained, a large flow will overwhelm the station, causing it to be unable to operate as expected.

What are reserve tanks for?

The reserve tank is a storage tank. It is used to perform similar work, only the water is not discharged from it, but is collected and stored for a certain time.

Some time passes, and heavy debris and waste settles to the bottom of the tank. One day is enough for the water to be cleared of heavy fractions of garbage and go to collection points. The reserve tank serves as an assistant to the redistributing tank during the season of heavy rains and snowmelt.

Sand trap device

The sand trap is a device that consists of a set of elements that look like a large sieve. Since rainwater contains a large amount of small stones and sand, which impede the operation of the purification system and reduce water purification, the use of a sand trap is necessary.

The device consists of the following elements:

1. The first compartment, which collects large parts of waste and debris.
2. The second part, in which there are a large number of inclined blades, through which water flows in the opposite direction, as a result of which heavy sand fractions precipitate to the bottom of the tank.
3. The third compartment, used to collect water and direct it to a treatment plant.

Since the drains contain sand and small fractions of debris in large quantities, periodic cleaning of the sand trap is necessary.

This device retains over 2/3 of the volume of sand, gravel and debris.

Oil trap device

The oil trap is a large reservoir that collects oil, gasoline, grease and other substances that form a film on the surface of the liquid.

The device consists of three parts, and the principle of its operation is as follows:

Stormwater enters the first compartment, where sand particles and solid wastes settle on the bottom of the tank, while reducing the speed of water flows.

The second compartment collects oils and fats. The compartment is equipped with a coalescent device, which consists of a large number of thin plates. Fats and oils pass through the plates, gathering into small particles. Gradually, the oils combine, becoming large drops that float to the surface of the water.

The third container collects partially purified water, which then flows by gravity further, where it undergoes its subsequent purification.

The removal of collected oil products is carried out by pumping, for which special equipment is used.

Sorption filter device

The sorption filter additionally collects fine particles of oil products that have passed through the oil trap. This filter works by adsorption, in which solids absorb oils. The adsorbent is most often activated carbon, which cleans wastewater as much as possible.

In order to periodically monitor the composition and level of wastewater treatment, revision wells will happen.

Differences and advantages of modern cleaning systems

Modern surface wastewater treatment plants achieve a high level of water purification, since the latest technologies and high-quality materials are used for this.

Today, the challenge is storm water purification from large quantities of oil products and the removal of various chemicals from them that can cause great harm not only to the human body, but also to the flora and fauna of the planet.

Modern wastewater treatment facilities.

Modern wastewater treatment plants have the following significant advantages:

1. High degree of purification of storm drains.
2. The use of containers, the bodies and parts of which are made of modern plastic, which prolongs the service life and makes the structures more reliable.
3. Simple design and ease of installation work.
4. The use of new sorption filters that more effectively remove oil and grease particles from waste and storm water.

Features of stormwater treatment plants

The functional responsibilities of storm sewer treatment plants are collection and treatment of wastewater from city streets and industrial enterprises. Since the composition of wastewater has noticeably deteriorated over the past years - it contains a large amount of oil products and chemical harmful substances, the use of these devices helps to improve the ecological state of the area where people live.

Features of modern storm cleaning systems.

The latest technologies and modern materials used in modern wastewater treatment plants purify storm water, discharging completely purified water into the soil, which is not capable of harming the soil, does not pollute drinking water sources and natural reservoirs, and is harmless to people, plants and animals.