RU2711925C1 - Composition for soil reclamation - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: invention relates to agriculture, to reclamation of disturbed lands with perspective of use for the purposes of accomplishment of urban territories. Composition for reclamation of soil contains peat, sand, ashes of sewage sludge combustion and seeds of perennial frost-resistant plants at following ratio of components, wt%: ash of sewage sludge combustion – 10.0–14.0, peat – 43.0–81.0, sand – 8.6–45.0, seeds of perennial frost-resistant plants – balance. Plants are represented by red clover or perennial ryegrass.

EFFECT: restoration of productivity of disturbed lands and provision of recycling of wastes with possibility of their useful use as component of organomineral mixture.

1 cl, 5 tbl

Description

The invention relates to agriculture in the field of reclamation of disturbed lands with the prospect of use for the improvement of urban areas.

Known soil for reclamation of disturbed lands (RF patent No. 2490240, publ. 08/20/2013), containing peat and anthropogenic components, characterized in that tail deposits of size class -8 + 3 kimberlite ore dressing and dehydrated are used as anthropogenic components activated sludge biological treatment plants for industrial effluents in the following ratio of components, wt. %:

Tailings 80-84 Dehydrated activated sludge 4-12 Peat Rest

The disadvantage of this soil for reclamation is that it does not take into account the chemical composition and the corresponding environmental hazard of the components.

Also known is a fertile soil (RF patent No. 2288907, published December 10, 2006) containing peat, sand and a humus-containing component, characterized in that it additionally contains wood sawdust, and as a humus-containing component - bioorganic fertilizer obtained by aerobic fermentation a mixture of animal waste and ground wood waste containing nitrogen, phosphorus and potassium in forms accessible to plants, having an ash content of 7-7.5% and pH = 5 ÷ 5.4, with the following ratio of components, wt. %:

Peat 25-30 Sand 50-60 Bioorganic fertilizer 2-5 Sawdust Rest

The disadvantage of this composition is the complexity of its manufacture, due to the use of aerobic fermentation to obtain a humus-containing component.

Known artificial soil (RF patent No. 2032319, publ. 04/10/1995), which contains a zeolite, a non-toxic gel-forming water-soluble polymer as moisture-consuming materials, a plant extract, condensed grass (hay) alfalfa biologically active substance (BAS), nitrogen-fixing component of the blue-green alga Nostoc Linckia and sapropel, wt. %:

Zeolite 15-33 Polymer 10-23 Alfalfa extract 5-10 Blue-green alga Nostos Zinckia 0.03-0.06 Sapropel Rest

The disadvantages of this soil composition are the complexity of the technology for preparing the components, the use of polymer as an artificial product of the chemical industry and the high content of aluminosilicates represented by zeolite.

A known composition for land reclamation with a mineral-organic mixture based on quartz-glauconite sand (RF patent No. 2193590, publ. 11/27/2002), which contains quartz-glauconite sand as mineral components, and sapropel as the organic base in the following the ratio of components, wt. %:

Quartz-glauconite sand 70-80 Sapropel 20-30

The disadvantage of this mineral-organic mixture is the possibility of using the composition only for sandy soils and insufficient illumination of the environmental hazard aspect of sapropelic mass as a useful component of the mixture.

Known technogenic soil obtained by heat treatment for the restoration of disturbed lands (RF patent No. 2520146, published on 06/20/2014), adopted as a prototype obtained by processing waste in the installation for the disposal of contaminated soils UZG-1MGZH, containing, by weight. %:

Heat treated waste 30-40 Peat 20-35 Sand 20-50

wherein the mixture of components contains, mass. %: vanadium oxide - 32.5; carbon - 31.4; aluminum oxide - 7.5; silicon oxide - 7.5; nitric oxide - 6.8; iron oxide - 5.3; hydrogen 4.4; magnesium oxide - 1.5; manganese oxide - 0.8; lead oxide - 0.4; chromium oxide - 0.4; zinc oxide - 0.4; nitrogen - 0.4 and associated impurities - 0.7.

The disadvantages of this soil composition are the increased complexity of obtaining the final product and the low fertility of the mixture based on heat-treated oiled soils.

The technical result of the invention is the restoration of the productivity of disturbed lands during restoration work and the disposal of available waste with the possibility of its beneficial use in urban environments.

The technical result is achieved by the fact that it additionally contains seeds of perennial frost-resistant plants, which are used as meadow clover or pasture ryegrass, and as heat-treated waste, ash is used to burn sewage sludge in the following ratio of components, wt. %:

sewage sludge ash 10.0-14.0 peat 43.0-81.0 sand 8.6-45.0 seeds of perennial frost-resistant plants rest.

The inventive composition for soil remediation includes the following components.

Seeds of perennial frost-resistant plants, such as Clover meadow or Rye grazing.

Peat should be used preferably horse-drawn, air-dry, meeting the technical parameters according to GOST R 51661.3 “Peat for soil improvement” (introduced 07.01.2000), GOST R 51661.4 “Peat neutralized. Technical conditions "(introduced 07.01.2001) or GOST R 52067" Peat for the production of nutrient soils. Technical conditions. "

When choosing a source of sand, preference is given to fine-grained fractions of river sands.

When calculating the composition of the mixture are taken into account:

- the chemical composition of the waste (the content of pollutants subject to regulation, primarily heavy metals);

- area of the reclaimed surface;

- the required mass of the mixture;

- the ratio of the components of the peat-sand mixture in the proportion (50-90)% :( 10-50)%.

The peculiarity of the composition is that it is proposed to use for the purpose of remediation and / or improvement ash burning sewage sludge as a waste of urban sewage treatment plants. Crude sludge from primary sedimentation tanks and compacted biological sludge from sludge compactors of treatment plants are sent for incineration. Sediment burning occurs in fluidized bed silica sand furnaces. Ash is a brown fine powder. When wetted, the ash becomes plastic and fluid. Particle size from 1 to 50

microns. The basic composition of the ash includes silicon oxide, phosphates of iron and calcium, a number of metal silicates; heavy metals are concentrated in a smaller fraction. The bulk density of the ash at a transport humidity of 0.68 g / cm ³ .

Initially, ash was collected from the incineration of sewage sludge. In the future, the waste is checked according to existing methods for toxicity (chemical composition and bioassay).

If the waste belongs to hazard classes I-III (from extremely hazardous substances to moderately hazardous substances), the waste cannot be used for the purpose of reclamation and / or improvement and is sent for storage to dumps. If the waste meets the IV-V hazard class (low hazard or practically non-hazardous), taking into account the content of pollutants in it, it is mixed with a peat-sand mixture in the calculated proportion (10-14)%: (90-86)% and seeds of long-term frost-resistant herbs in a special area.

The waste has a hazard class IV and can be used for the improvement of urban areas as a component of group II fertilizer, for example, for the improvement of road slopes in accordance with GOST R 54651-2011 “Organic fertilizers based on sewage sludge. Technical conditions ”(introduced on December 13, 2011).

In accordance with GOST R 17.4.3.07-2001 “Nature protection. The soil. Requirements for the properties of wastewater sludge when using them as fertilizers ”(introduced January 10, 2001) wastewater sludge may not be introduced into the soil if the content of harmful substances in the soil exceeds 0.8 MPC. Therefore, the introduction of WWS is possible with the condition of calculating the maximum allowable amount. In accordance with GOST R 54651-2011 "Organic fertilizers based on sewage sludge. Technical conditions ”(introduced on December 13, 2011), the calculation of permissible doses of the introduction of metals into the soil was carried out based on their content in the ash from the combustion of sewage sludge. The calculation results are shown in table 3.

The composition is illustrated by the following examples:

Example No. 1. For the restoration of disturbed lands on an area of 10 square meters. 200 kg of an organomineral mixture based on ash from burning sewage sludge are required, while the ratio of peat and sand components is set to 3: 2. Considering the content of heavy metals in the components of the mixture, the soil is mixed with seeds of frost-resistant herbs and is used to improve urban areas as a component of fertilizer of group II.

Example No. 2. For the restoration of disturbed lands on an area of 15,000 square meters. 310000 kg of an organomineral mixture based on ash from burning sewage sludge are required with a ratio of peat and sand components of 2: 1. Considering the content of heavy metals in the components of the mixture, the soil is mixed with seeds of frost-resistant herbs and is used to improve urban areas as a component of fertilizer of group II.

The effectiveness of the proposed composition is proven by laboratory tests. As a test culture selected plant battery

heavy metals Trifolium pratense of the Fabaceae family (Clover meadow) and lawn grass Lolium reppe of the Roaseae family (Rye grass). This type of clover is also a siderate, which allows you to further strengthen and enrich the soil with nitrogen compounds. The ryegrass tolerates temperatures well below minus 15 ° C without the presence of snow, does not require frequent watering and the introduction of additional fertilizers.

The peat-sand mixture is used in the following composition: air-dry peat and fine river sand in a proportion of 60%: 40%. Mixing is carried out mechanically, the resulting mixture is delivered to the site, intended for remediation, by road. The composition is applied to a flattened and compacted surface immediately after the snow cover has melted in spring (at a temperature transition of + 5 ° С). In the future, produce regular watering of crops with water. The experimental results are presented in tables 4 and 5.

The use of waste as a useful component of the organomineral mixture enhances the fertility of the soil, as evidenced by the positive effect on plant growth and development (for example, Lolium perenne and Trifolium pratense).

Claims (2)

Composition for soil remediation, containing sand, peat and heat-treated waste, characterized in that it additionally contains seeds of perennial frost-resistant plants, which are meadow clover or pasture ryegrass, and wastewater sludge ash is used as heat-treated waste in the next the ratio of components, wt.%: sewage sludge ash 10.0-14.0 peat 43.0-81.0 sand 8.6-45.0 seeds of perennial frost-resistant plants rest