RU202794U1 - Biofilter for air purification from polluting and unpleasant smelling volatile substances - Google Patents

Abstract

The utility model refers to biological treatment devices, mainly for air purification from pollutants, odors, and can be used for cleaning gas and ventilation emissions from sewage treatment plants, industrial enterprises, etc. The task is to create an easy-to-use and cost-effective biofilter for cleaning gas emissions from wastewater treatment plants containing a multicomponent composition of pollutants. The technical result consists in increasing the efficiency of cleaning gases from polluting and unpleasant smelling volatile substances. The technical result is achieved due to the fact that the biofilter for air purification from polluting and unpleasantly smelling volatile substances includes an open housing, located in it a perforated grid with a supporting layer and a fixed layer-carrier of microorganisms from the substrate and a sprinkler located in the upper part of the housing. The fixed layer-carrier of microorganisms is made of a mixture of vermicompost and wood bark of a fine fraction with a size of less than 1 × 1 cm. Sprinkler is made with the possibility of using purified waste water. 2 ill.

Description

The utility model refers to biological treatment devices, mainly for air purification from pollutants, odors and can be used for cleaning gas and ventilation emissions from sewage treatment plants, industrial enterprises, etc.

Known biofilter with granular biologically active compost as a carrier, containing a housing, a layer of granular biologically active compost as a carrier, patent [EP 0670176, IPC B01D53 / 84].

The disadvantage of this device is the laboriousness of making granules of the required size.

Known drip biofilter - a combination of a biofilter and a jet filter, implements the technology for removing volatile contaminants from gas streams, contains a housing and two purification zones, carriers of which contain microorganisms of the genus Hyphomicrobium, a feeding system for microorganisms, a capacity of an irrigation solution, supply and removal of polluted air [Patent EP 0669155 , IPC B01D53 / 84].

The disadvantage of this device is that water saturated with organic sulfur compounds in the second zone is pumped without additional purification to irrigate the carrier.

The closest technical solution, taken as a prototype to the claimed object, is an apparatus consisting of two cleaning zones. Pre-cleaning and air flow normalization takes place in a scrubber. Further, the gas-air mixture is fed into the filter, on the perforated grids of which there is a fixed layer-carrier of microorganisms from a substrate suitable for growing ornamental plants in it [Patent EP0329643A, B01D53 / 34].

The disadvantage of this device is the need to adjust the humidity and temperature of the gas-air mixture before feeding into the fixed-bed filter.

The considered purification systems using two - or multistage biofilters, or a combination of biofilters with physicochemical pretreatment have high efficiency. However, these systems are relatively expensive and can generate significant waste (waste water and / or solid (chemical) waste).

The task is to create an easy-to-use and cost-effective biofilter for cleaning gas emissions from wastewater treatment plants containing a multicomponent composition of pollutants.

The technical result consists in increasing the efficiency of cleaning gases from polluting and unpleasantly smelling volatile substances.

The technical result is achieved due to the fact that the biofilter for air purification from polluting and unpleasantly smelling volatile substances includes an open housing, located in it a perforated grid with a supporting layer and a fixed layer carrying microorganisms from the substrate and a sprinkler located in the upper part of the housing.

The fixed layer-carrier of microorganisms is made of a mixture of vermicompost and wood bark of the middle fraction, and the sprinkler is made with the possibility of using purified waste water.

FIG. 1 shows a biofilter installed directly above the wastewater treatment apparatus (a source of contaminated gas emission).

FIG. 2 shows the dependence of the gas concentration on the processing time in the biofilter.

The biofilter consists of a housing 1, a perforated lattice 4 installed in it and a carrier layer of microorganisms 3 located on it, the lower part of which is a supporting layer (not shown in the figure) and consists of a bark, and the upper part is a fixed carrier layer of microorganisms (on not shown), which is made of a substrate, namely, a mixture of vermicompost and wood bark of the middle fraction.

The body 1 is made open, and a sprinkler 6 is installed in its upper part. Purified waste water is used as an irrigation liquid.

The biofilter is installed on a wastewater treatment device 2 and is connected to a source of irrigation fluid supply, for example, to pump 5.

The lattice 4 with the carrier layer of microorganisms 3 is located in the horizontal plane (transverse to its walls) of the housing 1 and fills its entire space. At the same time, it serves as the basis for a supporting layer of inert fibrous material (bark).

The carrier layer of microorganisms 3 is a biologically active filter material.

A biofilter for air purification from polluting and unpleasant smelling volatile substances based on biochemical processes works as follows.

The air to be cleaned naturally enters the lower part of the housing 1, installed directly above the wastewater treatment apparatus 2 (a source of emission of contaminated gases), passes through the carrier layer of microorganisms 3, placed on the perforated grid 4, first through the supporting layer, then through the fixed layer - carrier of microorganisms. Periodically (as the carrier layer dries up), pump 5 supplies liquid (treated wastewater) to sprinklers 6. If there is enough moisture in the gas being purified, then irrigation is carried out less frequently. The purified air naturally mixes with the air mass around.

The contaminated gas moves through a fixed layer-carrier of microorganisms, which is a biologically active filtering material - vermicompost, mixed with a coarser fraction (tree bark). The activity of the filter material is based on the natural presence in the filter material of microorganisms capable of decomposing pollutants. Depending on the exhaust gas to be treated, the biofilter can be colonized by adapted organisms (in particular Hyphomicrobium, a sulfur-degrading microorganism). The carrier layer of microorganisms 3 is moistened with an irrigation liquid, that is, with purified waste water, and, if necessary, nutrients or buffer additives can be added to it. All residual products that form in the carrier layer of microorganisms 3 of the filter can be selectively removed by periodic irrigation.

An important advantage of the device is that the resulting drainage water from the biofilter can be neutralized in the wastewater treatment apparatus, above which the biofilter itself is installed. The runoff of organic matter is thus significantly reduced.

Another advantage of the biofilter, where the Hyphomicrobium strain is used, is that for the treatment of volatile sulfur compounds, including H ₂ S, it is allowed to purify gases at a neutral pH.

Biological purification in a biofilter occurs similarly to soil processes in natural conditions as follows: under the influence of aerobic groups of thionic and sulfur bacteria, an oxidative reaction of sulfur compounds occurs.

Measurements of the amounts of specific components of the gas-air mixture at the outlet of the model unit were carried out using the Geolan-1P gas analyzer in accordance with its operating manual. This device is included in the State Register of Measuring Instruments and has a wide range of sensitivity. The gas analyzer is designed for continuous, automatic, direct measurement of the concentrations of harmful and polluting substances (carbon monoxide, nitrogen dioxide, nitrogen oxide, sulfur dioxide, formaldehyde, ethanol) contained in the atmospheric air, the air of the working area. The permissible relative basic error of the device is not more than ± 20%, verification certificate No. 06.032600.20 until 26.05.2021.

Analysis of the gas-air mixture at the outlet of the model unit (operating time of the biofilter - 10 minutes) revealed a decrease in the concentration of sulfur dioxide: CO ₂ - 0.00%; CO - 0 mg / m ³ ; NO ₂ - 0.3 mg / m ³ ; SO ₂ - 19.7 mg / m ³ . With a biofilter operating time of 30 minutes, a decrease in the concentration of sulfur dioxide was also recorded: CO ₂ - 0.00%; CO - 0 mg / m ³ ; NO ₂ - 0.3 mg / m ³ ; SO ₂ - 10.4 mg / m ³ (Fig. 2).

The maximum permissible concentration in the working area of the treatment plant for SO ₂ (less than 10.0 mg / m3) was achieved after 40 minutes of gas purification in a biofilter.

Table 1 shows the results of comparative tests of carrier layer 3. A high level of cleaning efficiency is achieved when using carrier layer 3, consisting of a supporting layer (larch bark, loading height 10 cm) and a fixed carrier layer of microorganisms (a mixture of vermicompost with small larch bark fractions (less than 1 × 1 cm), loading height 10 cm).

Table 1

The component being defined Larch bark Mixture (vermicompost + larch bark) The initial concentration of components in the air of the work. zones MPC of the working area Loading height 10 cm (support layer) + 20 cm Loading height 10 cm (support layer) + 40 cm Loading height 10 cm (support layer) + 60 cm Support layer, loading height 10 cm + 10 cm mixture with coarse bark (more than 3 × 3 cm) Support layer, loading height 10 cm + 10 cm mixture with fine bark (less than 1 × 1 cm) CO, (mg / m ³ ) 0 0 0 0 0 0 20 NO ₂ , (mg / m ³ ) 0 0 0 0 0 0 2 NO, (mg / m ³ ) 0 0 0 0 0 0 five SO ₂ , (mg / m ³ ) 2.4 1.07 0.43 0.23 0.07 9.9 ten H ₂ CO, (mg / m ³ ) (formaldehyde) 0.71 0.40 0.08 0.017 0.00 1.26 0.5 C ₂ H ₅ OH (ethanol), (mg / m ³ ) 0 0 0 0 0 0 1000

In addition to achieving the SO ₂ standard, the advantages of this method include:

- there is no generation of waste requiring special treatment;

- biomass after a certain period of time is composted together with filter material;

- low cost of investment, as well as low operating costs.

Claims (1)

Biofilter for air purification from polluting and unpleasantly smelling volatile substances, including a housing, a perforated grid located in it with a fixed layer-carrier of microorganisms from a substrate and a sprinkler, characterized in that it additionally contains a supporting layer located between the perforated grid and a fixed layer-carrier made of a mixture of vermicompost and wood bark of fine fraction with a size of less than 1 × 1 cm, and the body is made open, and the sprinkler is located in its upper part and is made with the possibility of using purified waste water.

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