Knowledge base

List of articles

1. ADVANTAGES AND DISADVANTAGES OF COMMON VENTILATION METHODS

2. WHY ACTIVE NEUTRALIZER?

3. ACTIVATED CARBON – AN EFFECTIVE CONTRIBUTION TO ODOR NEUTRALIZATION

4. PRINCIPLE OF OPERATION OF THE ACTIVE ODOR NEUTRALIZER

1. Advantages and disadvantages of common ventilation methods

Gravity ventilation

Advantages

Defects

Signs

Gravity ventilation

(fireplaces with coal insert)

Advantages

Defects

Signs

2. Why is the neutralizer active?

Hydrogen sulfide

Hydrogen sulfide Hydrogen sulfide (H2S) is a gas that is produced in municipal sewage as a result of the anaerobic decomposition of organic compounds containing sulfur compounds. It most often occurs in situations where sewage remains for a long time without aeration, e.g.:

Hydrogen sulphide is a gas: toxic, mutagenic, carcinogenic, flammable and highly corrosive to concrete and steel elements. This compound is also the main cause of unpleasant odors that often appear in the close vicinity of sanitary sewage infrastructure. It is therefore important to effectively prevent hydrogen sulphide and other harmful compounds from entering the atmosphere and to prevent their accumulation inside engineering facilities.

The photo below shows a corroded mesh fence around the sewage pumping station.

Common solutions

Two solutions for ventilation of the pump room chamber are commonly used in sanitary sewage infrastructure:

The first solution often ensures the required level of well ventilation, but carries the risk of unpleasant odors occurring in the vicinity of sewage facilities (pumping stations, expansion wells, inspection wells, sewage treatment plants).

The second solution reduces the occurrence of unpleasant odors, but the carbon insert generates additional resistance to the flowing air. As a result of incomplete ventilation, hydrogen sulphide accumulates inside the well, which causes corrosion of concrete and, in the case of pumping stations, it also penetrates through the protective pipes of electrical cables into control cabinets, where it negatively affects the automation elements operating there.

The first solution often ensures the required level of well ventilation, but carries the risk of unpleasant odors occurring in the vicinity of sewage facilities (pumping stations, expansion wells, inspection wells, sewage treatment plants). The second solution reduces the occurrence of unpleasant odors, but the carbon insert generates additional resistance to the flowing air. As a result of incomplete ventilation, hydrogen sulphide accumulates inside the well, which causes corrosion of concrete and, in the case of pumping stations, it also penetrates through the protective pipes of electrical cables into control cabinets, where it negatively affects the automation elements operating there.

3. Activated carbon - an effective contribution to neutralizing odors

Active carbon

Activated carbon is a material characterized by a very large specific surface area in relation to mass. One gram of activated carbon can contain up to 3,000 square meters of surface area. This property results from the very extensive structure of this material. The mass of carbon consists of numerous pores (micropores and mesopores), which are characterized by very small sizes, thanks to which there are millions of them in one gram of carbon. The sizes of the pores that make up the carbon structure are so small that they allow retaining particles composed of even only three atoms, such as hydrogen sulfide. The above-mentioned hydrogen sulphide is one of the main compounds responsible for unpleasant odors emanating from sanitary sewage infrastructure devices (sewers, manholes, sewage pumping stations). The described process of retaining particles and more complex chemical compounds is called adsorption. Activated carbon is not the only material that can adsorb chemical compounds that cause unpleasant odors. However, due to the size of the specific surface, which significantly exceeds the surface of other materials, it is the most frequently chosen material for odor removal. Activated carbon – an effective way to reduce odor release Additionally, activated carbon, thanks to the use of impregnation with a specific chemical, can even more effectively reduce the release of odors into the atmosphere. Thanks to the impregnation, hydrogen sulphide flowing through the volume of activated carbon is transformed into other chemical compounds that do not cause unpleasant odors, which are also retained on the surface of the activated carbon bed. The described process is called odor neutralization. This is where the name of odor removal devices comes from: odor neutralizers.

Biomass to remove air pollutants

Biomass to remove air pollutants

An alternative method of removing air pollution is the use of a biological deposit (biomass). This process is based on microorganisms living in the volume of the biological bed fill, which may be wood chips, bark, straw and other organic matter. In addition to taking food from the biological bed, microorganisms also consume compounds that pollute the air and cause unpleasant odors. Although this method is considered effective, it has many disadvantages. To function properly, biomass must be maintained in appropriate conditions that allow the survival of the microorganisms that colonize it. This means that appropriate humidity and temperature must be constantly maintained in biofilters (odor removal devices filled with biomass). Additionally, hydrogen sulphide, which is a toxic compound, in too high a concentration may cause the death of microorganisms and thus stop the air purification process. Another important aspect is the change in the properties of biomass over time, which results from the continuous life of microorganisms. Over time, the filling of the biological bed biodegrades, and thus generates greater pressure losses in the flowing air, and therefore lower flow. Thanks to its structure, impregnated activated carbon is an effective, durable material that does not require any work and guarantees constant functioning parameters over a long period of time. Unlike biomass, it is resistant to hydrogen sulphide, the removal of which is the main task of odor removal devices.

4. Principle of operation of an active odor neutralizer

Gravity ventilation

Odors entering the pumping room and emerging inside are sucked out using an exhaust fan located at the top of the odor neutralizer.

The negative pressure generated by the fan inside the chamber causes a simultaneous inflow of fresh air from the atmosphere through the ventilation chimney, which serves as an air intake.

The air flowing through the neutralizer is cleansed of impurities. This operation of the system ensures that the air inside and outside the pumping room is constantly clean.

Advantages

Signs