RU2700529C1 - Method of cleaning crushed stone at liquidation of spills of oil products at enterprises of railway industry, as well as accidents and spills of petroleum products on traction roads of general use - Google Patents

Abstract

FIELD: technological processes.SUBSTANCE: invention relates to methods of cleaning ballast layer of railway track from contamination by oil products. Crushed ballast layer is placed in drum sink and supplied aqueous solution reagent destructor. For one hour, crushed rock is washed at 25–50 °C. Then, washing solution together with fine fractions of ballast is discharged into settler and separated into phases. Cleaned detergent solution is again supplied to a drum sink for cleaning of the next ballast load.EFFECT: reduced toxicity of treated ballast.3 cl

Description

The invention relates to technologies for cleaning crushed stone during the elimination of oil spills at the enterprises of the railway industry, as well as accidents and oil spills on traction paths of general use.

The most common pollutants in the territories of enterprises in the railway industry are oil, oil products, fuel oil, fuel, and lubricants. The reason for the pollution of railroad tracks with oil products is their leakage from tanks, faulty boilers, when refueling wheel axle boxes. In addition, the design features of locomotives imply the flow of lubricant through the technological holes.

According to GOST 7392-2014, crushed stone from dense rocks, which are a fairly high-grade material, is used for the ballast layer of traction paths. Thus, for the railway industry, the largest share of oil pollution is not so much on the ground, but on crushed stone.

The amount of oil pollution ranges from 5 to 20 g per 1 kg of crushed stone. Railway transport enterprises occupy territories from 2 to 50 hectares (locomotive and car depots - 4-5 hectares, territories of washing stations, railway stations, passenger carriage preparation centers, slag impregnation plants - 12 hectares).

Based on the foregoing, today the problem of cleaning crushed stone from oil products is relevant, both from the point of view of environmental protection, and from the economic point of view of reusing crushed stone for adding ballast layer of railway tracks.

A known method of cleaning the crushed stone of the rail track using a screening unit for separating debris moved by the conveyor belt, as well as using the water supply, consists in the fact that the crushed stone cleaned after double cleaning by mechanical means and using the water supply is again brought onto the rail track. Contaminated water is purified with the formation of sediment, which is applied to the garbage for their joint transportation by a conveyor belt (patent RU2249643, published July 15, 2003).

The disadvantage of cleaning crushed stone from oil products by washing with water is the problem of further purification of water from washed oil products.

The most famous and widely applicable methods at present for eliminating oil pollution are soil excavation followed by burial or thermal treatment, evaporation of the pollutant in the soil, and biological treatment. Of all the technologies for eliminating the consequences of soil pollution by oil products, the most environmentally friendly is bio-treatment at the site of pollution. Its advantage is the relative simplicity of the technological implementation of the installation and operation, as well as the relatively low financial costs. It is widely used in many countries, successfully used in the cleaning of soils from diesel fuel and other petroleum products.

Currently, in the process of bioremediation mainly aerobic bacteria are used. Studies have shown their ability to actively decompose hydrocarbons, identified requirements for conditions that are most conducive to their growth. Their metabolism has been studied in detail and it is shown that the products of microorganisms processing petroleum products are not dangerous to humans and the environment.

The closest analogue to the patented solution is a method of biological treatment of soil from oil pollution (Patent RU2104248, published 02.10.1998). The method involves applying a preparation of hydrocarbon-oxidizing microorganisms to the oil substratum of the contaminated area. Before application, the microorganisms of the preparation are cultured in a medium containing oil substrate of the contaminated area. Moreover, the oil substrate is taken in such an amount that ensures the symbiotic growth of the drug’s hydrocarbon-oxidizing microorganisms and the oil substratum.

However, this cleaning method requires observing the temperature regime and a certain soil moisture, and is also a fairly long cleaning method, since the biological cleaning time is from three months to several years.

The technical problem lies in the search for quick cleaning methods that can be carried out in places of pollution.

The problem is solved by mechanical washing of the ballast with a reagent-biodestructor solution instead of water to clean road gravel from oil products directly at the places of its dislocation.

The technical result of the proposed solution is to reduce the risk of departure to class 4 (according to FKKO: 84210102214) in a period reduced to one hour, as well as further passive exposure and an additional reduction in ballast toxicity due to the reagent remaining on the ballast returned to the path after washing .

The proposed technology for cleaning oil-contaminated crushed stone of a railway track is based on a drum washing of crushed stone, but instead of water, a solution with a biodegradation reagent (products of the Hydrobreak series) is used. The starting material is placed in a rotating drum (ballast from crushed stone contaminated with oil products (oil content 15% or more) , FKKO code: 84210101213), then a solution with a reagent is supplied.

A method for cleaning crushed stone on traction paths includes the steps of loading ballast from crushed stone in a drum washing drum in an amount not exceeding 30% of the volume of the sowing part of the drum washing containing more than 15% of oil products; a washing solution in the amount not exceeding 50% is pumped the drum washing drum volume containing 1.25% of a biodestructor reagent (the ratio of water and reagent can be increased to 1: 1 depending on the pollution of crushed stone with oil products), which is a mixture containing the following components (wt.%):

Surfactant <3

glycol <15

water - the rest

pH = 6

for one hour, the rubble is washed with a biodegradation reagent solution by means of a drum washing at 25 ÷ 50 ⁰ С, after which the washing solution together with small fractions of ballast, the size of which is smaller than the cells of the washing part of the sink, is taken into the sump through the nozzles and separated by settling into phase, then the washing solution is again fed into the drum washer for washing the next portion of ballast.

The cell size of the sowing part of the drum washing is 50-60 mm.

In the particular case of the invention, the reagent contains natural organic substances and weak organic acids.

In the particular case of the invention, the washing of the ballast is carried out under the influence of direct ultraviolet radiation.

In the particular case of the invention, the aqueous phase of the waste after washing is diluted with water 20-25 times and drained into the sewer.

Drum washing includes a drum, which consists of a deaf and sowing parts. The washed material is fed into the drum. In the blind part of the drum (scrubber), equipped with rippers and thresholds, there is a disintegration of the material and erosion of the clay contained in it. In the sowing part of the drum, the material is dispersed according to size classes and freed from clay dissolved in water.

As a reagent, products of the Hydrobreak series, a biodestructor of oil pollution, are used.

The results of laboratory analyzes of ballast from crushed stone contaminated with oil products (before cleaning) and ballast from crushed stone contaminated with oil products (after cleaning) showed a decrease in the risk of waste to class 4, and when the dilution ratio of the water extract from the waste after cleaning is 23 times there is no harmful effect on aquatic organisms .

These results suggest that with increasing washing time and exposure to the reagent solution, as well as under the influence of ultraviolet radiation (for example, direct sunlight or artificial UV lamps), the toxicity of the waste will decrease.

The result of the proposed technological cleaning is purified crushed stone and a solution-catalyst, which can be used for re-washing.

The liquid drained from the sink after washing can be used to clean oil sumps; after initial use, the reagent can work for another one to two weeks.

Washed ballast can be used for re-placement on railway tracks, as well as when falling asleep (reclamation) of solid waste landfills.

Claims (8)

1. A method for cleaning crushed stone on traction paths, comprising the steps of loading ballast from crushed stone in a drum washing drum in an amount not exceeding 30% of the volume of the sowing part of the drum washing, containing more than 15% of oil products, using a pump to supply washing solution in a volume not exceeding 50% of the drum washing drum volume, containing 1.25 ÷ 50% biodestructor reagent, which is a mixture containing the following components (wt.%): Surfactant <3; glycol <15; water - the rest pH = 6, for one hour, the rubble is washed with a biodegradation reagent solution by means of a drum washing at 25 ÷ 50 ° С, after which the washing solution together with small fractions of ballast, the size of which is smaller than the cells of the washing part of the washing, is removed through the washing nozzles to the sump and separated by settling into phase, then the washing solution is again fed into the drum washer for washing the next portion of ballast. 2. The method of cleaning rubble according to claim 1, in which the washing of the ballast is carried out under the influence of direct ultraviolet radiation. 3. The method of cleaning crushed stone according to claim 1, in which the aqueous phase of the waste after washing is used to clean oil sumps.