CZ202275A3 - Sludge from sewage treatment plants - Google Patents

Abstract

The solution concerns sludge from sewage treatment plants, the essence of which is that it contains the addition of ash from the burning of peat and/or the burning of plant crops that can be used for energy, and/or the burning of wood. The mass fraction of fly ash to the mass fraction of sewage sludge is in the ratio of 1 to 90% to 99 to 10%. Sludge possibly contains a proportion of heating plant ash from coal combustion, or a proportion of lime product from flue gas desulphurisation.

Description

Sludge from sewage treatment plants

Field of technology

The invention relates to sludge from sewage treatment plants.

Current state of the art

A frequent use of sludge from wastewater treatment plants is their treatment in order to obtain material for recultivation of land areas and for agricultural use.

According to the final method of using sewage sludge, for example recultivation, for this purpose e.g. heating plant ash, products from desulphurisation of heating plants and organic material of animal or plant origin are added to the sludge.

This material is then transported to the area degraded by previous use. The disadvantage of using these materials is the release of forms of nitrogen and nutrients, in the case of significant seepage of the leachate from the mentioned mixture, there is a risk of unwanted contamination of the soil, or even water.

Another disadvantage after the storage of such material is also the possible occurrence of the production of gases causing the greenhouse effect, which is due to the incomplete decomposition of organic matter, e.g. methane and carbon dioxide.

The aim of this invention is therefore to create such a mass for recultivation that is physically and biologically stable, substantially reduces the production of contaminants into the environment and then enables the purposeful use of the contained nutrients and organic components in the target mass for recultivation, which can also be suitable for use in the area agriculture and forestry, if such use takes place according to the currently valid legislation.

The essence of the invention

The essence of sludge from wastewater treatment plants according to the present invention is that it contains the addition of ash from the burning of peat and/or the burning of plant crops that can be used for energy, and/or the burning of wood. The mass fraction of fly ash to the mass fraction of sewage sludge is in the ratio of 1 to 90% to 99 to 10%. Sludge from wastewater treatment plants may contain a proportion of thermal ash from coal combustion, or a proportion of lime product from flue gas desulphurisation. The mass content of the biological-enzymatic preparation with bound microorganisms is in the range of 0.02 per thousand to 5 percent of the laboratory sludge dry matter.

Sludge from sewage treatment plants may contain waste from plant tissues, animal droppings and manure, including contaminated straw and farm organic products, or waste from forestry.

An example of the implementation of the invention

To create a suitable mass for recultivation, with corresponding physical, chemical and mechanical properties, it is advisable to use sludge from sewage treatment plants.

According to this invention, ash from the burning of peat, the burning of plant crops that can be used for energy, or the burning of wood is added to the sludge from sewage treatment plants. Ash of this type is added to the sewage sludge in a weight ratio of 1 to 90% of ash and 99 to 10% of the weight of sewage treatment sludge.

- 1 CZ 2022 - 75 A3

Ash from the burning of peat, the burning of energy-usable plant crops, and wood is relatively porous and is capable of absorbing a portion of the resulting gases, the aqueous leachate of the processed mixture, and binds the nutrient portion in the target reclamation mixture. Plant crops that can be used for energy are crops grown to obtain biomass suitable for direct combustion, gasification and anaerobic digestion.

Individual ashes from the burning of peat, energy crops, and wood can be contained in sludge from wastewater treatment plants individually or in any combination.

The resulting mass of recultivation material has a higher final dry matter, better handling and better load-bearing capacity due to the proportion of ash from the burning of peat, the burning of plant crops that can be used for energy, or the burning of wood.

The addition of an effective amount of an enzymatic preparation with bound microorganisms to support the decomposition of organic matter (under aerobic or anaerobic conditions) further improves the processing and production process of reclamation matter.

The mass content of the biological-enzymatic preparation with bound microorganisms is in the range of 0.02 per mille to 5 percent of the laboratory sludge dry matter.

To the mixture of sewage sludge and ash from the burning of peat, the burning of plant crops used for energy, or the burning of wood matter, it is possible to add a proportion of heating plant ash from the burning of coal or lime product from flue gas desulphurisation for faster mineralization of the organic part and better physical properties of the target mixture for the reclamation of devastated areas or loaded surfaces.

Sludge treated in this way for recultivation material is advantageously used on the one hand for land reclamation, or as a means of fertilizing agricultural land.

Claims (5)

PATENT CLAIMS 1. Sludge from wastewater treatment plants, characterized by the fact that it contains the addition of ash from the burning of peat and/or the burning of plant crops that can be used for energy and/or the burning of wood. 2. Sludge from sewage treatment plants according to claim 1, characterized in that the mass fraction of ash to the mass fraction of sewage sludge is in the ratio of 1 to 90% to 99 to 10%. 3. Sludge from wastewater treatment plants according to claim 1, contains a proportion of thermal ash from coal combustion, or a proportion of lime product from flue gas desulphurisation. 10 4. Sludge from sewage treatment plants according to one of the previous claims, characterized in that the mass content of the biological-enzymatic preparation with bound microorganisms is in the range of 0.02 per mil to 5 percent of the laboratory solids of the sludge. 5. Sludge from sewage treatment plants according to claims 1 to 3, characterized by the fact that it contains waste from plant tissues, animal droppings and manure, including polluted straw and farm organic products, 15 or waste from forestry.