Problems of utilization of municipal solid waste. Disposal of garbage at landfills, solid domestic and industrial waste Danger of burial of solid domestic waste

Any city in our time creates a huge amount of waste, especially megacities. So, for example, more than 9,000 tons of garbage are removed from Moscow alone. Specifically, municipal solid waste (MSW) includes non-ferrous and ferrous metal, paper, cardboard, plastic, glass and biological waste, such as leather goods, food residues, vegetable waste.

Removal, processing, burial and other manipulations with garbage have long been “put on the conveyor”. This niche is shared between businessmen, special organizations and utilities. And for the most part, all garbage is sent to a municipal solid waste landfill (MSW landfill) or plain language- to the landfill.

How does a solid waste landfill work?

These polygons have certain rules in the device and organization. First, the life of the landfill is 15 to 20 years, and it should be located at least 1 km from the nearest residential building. Groundwater should lie deeper than two meters, and a protective forest belt 20 meters wide will be created around the landfill.

The landfill cannot be located on the territory with a reservoir. It is interesting that under the reservoir in this rule not only rivers and lakes are meant, but also springs. Moreover, there are small wells in the landfills to check the degree of groundwater pollution.

A good asphalt road is also being laid to the landfill. The landfill area varies, but in any case it is divided into several sectors, which are used in turn, each such area is designed for a duration of three to five years of use, depending on the amount of incoming garbage. The first of the sectors has been used for only a couple of years.

Another interesting topic of the construction of a solid waste landfill is the features of waste disposal and isolation methods. In addition to the protective forest belt, there are special nets and screens that prevent the spread of biogas. Biogas is the result of methane and hydrogen fermentation, which significantly pollutes the atmosphere.

This is how garbage is disposed of. First, a pit is dug out, which is covered from the inside with materials that prevent the penetration of toxic substances into the ground. In winter, for example, they sometimes use construction waste: concrete, brick and the like. After that, compressed blocks or just waste from garbage trucks are dumped into the pit, reaching a layer of about two meters, and sprinkled with earth every day. In addition, the waste is processed by compactors in order to achieve the highest possible efficiency from the volume of the pit. There is also a layout option, in which not pits are pulled out, but trenches, this ensures the convenience of garbage trucks moving around the landfill, although it is possible only on a fairly flat surface.

You can make money on the maintenance of a landfill for municipal solid waste. And also good ones. The garbage disposal itself, not to mention the processing or resale of non-ferrous metal, costs money. This money is paid by everyone who uses the services of garbage collection, services and entrepreneurs who own one or another landfill. Wherever money is circulating, there will definitely be someone who gets this money around the law. And landfills are no exception.

Most often, monitoring or environmental protection systems suffer. They may simply not be deployed, for example, they may not use countermeasures against biogas, they may not install devices for measuring pollution. Or place a landfill in the wrong place, if it is cheaper, closer to a residential area.

A huge hole in the legislation for fraud is the fact that in our country there is no system for measuring the amount of garbage. Because of this, the situation “we write three, five in the mind” often arises, and both entrepreneurs take advantage of this moment, twisting accounts, and housing services, which underestimate order data, and excess money from taxpayers goes into their pockets. In such a business that is not yet controlled by law, there are still many ways to cheat, and people, unfortunately, can only hope for someone else's conscience and responsibility.

Waste disposal is the isolation of household or industrial waste (most often radioactive or toxic) by placing it in the Earth's mountainous bowels or sea depths.

According to rough estimates, the said world stock of recycled material reaches 1,200 billion tons, while more than a third of the total is solid waste.

An industry such as mining rocks, gives huge spaces in which it is possible to carry out waste disposal. Mining companies, annually process more than 30 billion tons hard rock, of which only 60% goes to tailings, after primary processing ores. About 45-65% of MSW is used to fill voids in developed quarries, dips or cracks. 1% goes to bookmark the dug space. And more than 5% of the annual salvage is buried in the sea abyss.

The area of ​​land allocated for waste disposal has long approached 1 million hectares.

Therefore, the use of worked out mountainous space for such purposes is a promising technology.

Landfills for storage of MSW and other hazard classes

In addition to the sea subsoil and mountain spaces, the most common method in Russia is burial at special landfills, they are protected structures, the purpose of which is:

• disposal of collected waste;
• site for the neutralization of hazardous (infectious and toxic) types of waste;
• temporary storage of non-utilized materials;

each region of the country has its own landfill, the size and area of ​​which depends on the number of industrial enterprises in the city and the population, as well as other economic indicators. It should be designed for the amount of garbage that the city produces annually. excessive big sizes, this is not rationally used territory.

EEC countries have similar landfills on their territory and divide them into three types, depending on the class of waste, such landfills can separately place the following types of waste:

• relating to 1 - 4 hazard classes;
• inert;

although it is not always easy to draw a line between, for example, inert and dangerous, since the former, as a result of any changes in the composition or decay process, can produce just the same dangerous elements, such as methane gas.

In the Russian Federation, there are certain standards according to which waste disposal should be carried out at landfills that have the following facilities on their territory:

• A workshop for the initial processing or neutralization of waste materials in order to reduce their level of danger, as well as to reduce the volume of the object to be buried.
• A specially designated area, determined by the standards, for deep burial.
• Garage, with all the necessary vehicle units, for loading, transporting and delivering the collected garbage to the storage site.

Creating polygons

When organizing sites for waste disposal, the main role is played by:

• the right choice of territory for the organization of the site;
• suitable area for the construction of buildings;
• availability of all necessary engineering structures and facilities;
• a certain order, filling the site with waste;
• depth, pre-treated scrap;
• monitoring environment, the absence of large or rare populations of animals or birds nearby;
• control over the formation of gas, as well as the possibility of its collection and transportation if necessary;
• timely collection or removal of leachate,

Also, do not forget that before burial it is required to track all activities in relation to them, starting with education.

Modern requirements for the preparation of such places require compliance with all sanitary and epidemiological requirements, according to which the site must be equipped with the following facilities:

• a base made of compacted material, in which the walls are combined from mineral and artificial materials;
• sufficiently wide passages;
• to collect seeped water from sewage treatment channels;
• for the collection and transportation of methane gas released during waste disposal;
• structures for landscape cleaning of lands, with the help of reclamation.

There are also underground types of places for burial, these are:

• abandoned mines;
• wells;
• formed voids;
• old and no longer usable oil fields;

and other worked-out voids, which are intended for the disposal of radioactive, toxic and other types of such a hazard class.

Do you know that in the suburbs there is a landfill built according to European standards

MINISTRY OF EDUCATION AND SCIENCE

DONETSK PEOPLE'S REPUBLIC

DONBAS NATIONAL ACADEMY OF CONSTRUCTION AND ARCHITECTURE

Institute of Urban Economy and Environmental Protection

Department of Applied Ecology and Chemistry

Test

discipline: "Technoecology »

Student Nizhinskaya Anastasia Yurievna

Profile: "Engineering environmental protection"

Course - 4 Semester - 8

Head: Ph.D., Doroshenko T.F.

Number of points ____ECTS score____

Plan

1. Burial of solid household waste.

2. The main methods of disposal of medical waste.

Burial of solid household waste.

The cheapest way to get rid of waste is to bury it. This method goes back to the simplest way - to throw something from the house into a landfill. History has shown that simply throwing unusable items out of the house cannot solve the problem. In the 20th century, it was necessary to move from the spontaneous creation of landfills to the design and implementation of special engineering facilities, landfills for the disposal of household waste. The project provides for minimization of environmental damage, strict observance of sanitary and hygienic requirements.

Construction of a landfill and disposal of solid waste

Waste from residential buildings, public buildings and institutions, trade enterprises, public catering, street, garden and park estimates, construction waste and some types of solid industrial waste of III-IV hazard class are placed at solid waste storage sites.

Typically, a landfill is built where clay and heavy loam can serve as a base. If this is not possible, a waterproof base is provided, which results in significant additional costs. The area of ​​the land plot is selected with the condition of its service life (15-20 years) and, depending on the volume of disposed waste, can reach 40-200 hectares. The height of waste storage is 12-60 m.

Landfills can be low-load (2-6 t/m²) and high-load (10-20 t/m²). The annual volume of accepted waste can range from 10 thousand to 3 million m³. The technological process of waste disposal is carried out, as a rule, by the cart method, which allows for the gradual introduction of environmental measures without waiting for the completion of the operation of the landfill as a whole. The technology of MSW storage at landfills provides for the installation of water-resistant screens to protect groundwater and daily external insulation to protect the atmosphere, soil, and adjacent territories. All work on storage, compaction and isolation of MSW at landfills is carried out mechanized.

The organization and construction of the landfill is carried out in accordance with the legislation in the field of environmental protection and waste management, sanitary-epidemiological and urban planning legislation, as well as in the presence of a positive conclusion of the state urban planning expertise for this construction project.

A modern solid waste landfill is a complex of environmental structures designed for centralized collection, neutralization and disposal of solid waste, preventing the ingress of harmful substances into the environment, pollution of the atmosphere, soil, surface and ground water, the spread of rodents, insects and pathogens.

The polygon should include:

a waste disposal site;

a site for the placement of a workshop for sorting and processing waste;

composting area

administrative and economic zone;

· engineering structures and communications for the life support of the landfill and environmental safety;

express laboratory;

area for radiation monitoring of waste.

The landfill for waste disposal along the perimeter must have a fence with a height of at least 180 cm. On the landfill along its perimeter, starting from the fence, the following should be placed in sequence:

An annular channel

ring road with high-quality hard surface;

· storm drains along the road or ditches.

The building density of the administrative and economic zone of the landfill should be at least 30%. In the administrative and economic zone are located:

administrative and amenity premises, laboratory;

· warm parking for special vehicles and mechanisms (canopy);

a workshop for current repair special vehicles and mechanisms;

storage of fuel materials;

· automobile scales (on polygons over 100 thousand tons/year);

· checkpoint;

boiler room (if necessary);

control and disinfectant bath;

The main structure of the landfill is the solid waste storage area. It occupies the main area of ​​the landfill, depending on the volume of received solid waste. The storage area is divided into stages of operation, taking into account the provision of waste reception for 3-5 years, as part of the first stage, a start-up complex is allocated for the first 1-2 years. The operation of the next stage is to increase the mound of solid waste to the projected mark. The breakdown of the storage area into queues is carried out taking into account the terrain.

Storage areas must be protected from runoff surface water overlying land masses.

To intercept rain and flood waters, a drainage ditch is being designed along the border of the site. Along the perimeter of the landfill on a strip 5 - 8 m wide, trees are planted, engineering communications (water supply, sewerage) are laid, electric lighting masts are installed; in the absence of engineering structures on this strip, cavaliers (warehouses) of soil are dumped to use it for solid waste insulation, in any case, no more than 5% of the entire landfill area.

Symbols: A - ground water, B - dense clay layer, C - plastic layer, D - drainpipe system, E - geotextile layer, F - gravel, G - drainage layer, H - soil layer, I, J - layers soil where garbage is stored K- gutter (pond).

Processes taking place with MSW at landfills

During the operation of the landfill, as well as for a long time after its reclamation, landfill gases are released into the atmospheric air, seepage water (filtrate) is formed, and the geo-indicators of soils under the landfill body change, which leads to an increase in the filtration capacity of soils and, as a result to groundwater pollution.

The reactions taking place in the solid waste disposal body under aerobic conditions can be schematically represented as follows:

With further oxidation, the transformation of the cellular substance begins:

In a typical landfill, the aerobic oxidation process most often results in the formation and accumulation of high concentrations of fatty acids, which limits the process of aerobic decomposition.

Anaerobic biodegradation requires the presence of microorganisms different types included in the mixed population. A group of hydrolytic or acidogenic bacteria provides the initial hydrolysis of the substrate to low molecular weight organic acids and other compounds, including methane.

The first step in the development of environmental measures at MSW landfills should be the assessment of data on the following characteristics:

location of the solid waste landfill or landfill;

type of landfill (landfill);

The period of operation

types, characteristics and amount of disposed waste;

storage method;

· thickness of storage layers;

Availability of screens, drainage and gas collection systems;

· chemical and biological characteristics of the landfill mass;

· hydrogeological conditions of adjacent territories.

AT real conditions obtaining most of the above data is difficult due to the complete or partial lack of information. Information on illegal landfills today can only include data on their size and location.

At present, in the world practice, the most advanced method of storing solid waste, which allows to reduce the negative impact on the environment, is the arrangement of "managed" landfills. When choosing a site for waste storage, the features of the area where the landfill is located are taken into account: climate, topography, geology, hydrological processes, water balance, etc. Preparation of the landfill includes compaction and waterproofing of the bed, the installation of a drainage system for the removal of seepage water, laying pipes for collecting biogas . To manage such a landfill, a number of technological measures are recommended.

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New Russia fully inherited from the USSR the resource and environmental problems in the handling of industrial and domestic waste, the accumulation of which has become an avalanche and irreversible.

Ryabov Yury Vasilievich
well-known enrichment technologist, senior Researcher, candidate of technical sciences. Graduate of the Freiberg Mining Academy (Germany).
At the Institute of Mining and Chemical Raw Materials (GIGHS of the USSR Ministry of Chemical Industry), he developed enrichment schemes various kinds mining and chemical raw materials (phosphate, sulfuric, boric, etc.). Repeatedly provided scientific and technical assistance in organizing its processing abroad (Syria, Egypt, Tunisia, Vietnam,
Finland)

All wastes, as we have shown earlier in information and analytical reviews, represent the material base of industrial production, innovation and technological potential and, at the same time, a source of medical and environmental hazard to the environment. However, if the complex polycomponent composition of various types of industrial waste from the mining and industrial complex, the chemical complex and the fuel and energy complex requires their special study and evaluation in order to select the directions and technologies for their processing, then municipal solid waste (MSW) is a secondary raw material that is ready for use under the conditions of initial collection and sorting . Obviously, non-compliance with these conditions leads to the need for burial or disposal of both accumulated (current) MSW and stale ones. With the current waste management, the consumer value of various types of secondary raw materials is largely lost, but the environmental risks of its storage and disposal processes, among which incineration predominates, are not eliminated. In our country, stable ideas have developed that the involvement of technogenic resources, including secondary raw materials, in industrial use is hindered by the lack of necessary technologies. Unfortunately, the latest domestic technologies of applied academic science remain unclaimed by business and government at all levels.

In the Joint Institute for High Temperatures of the Russian Academy of Sciences, only in the last 10–15 years, innovative technologies have been developed for 100% processing of ash waste from coal combustion at thermal power plants, deep purification of industrial waste from various specialized enterprises using a new effective reagent - ACP flococoagulant, sealing and canning with its use of stale finely dispersed waste, including highly toxic waste, etc. The JIHT RAS focuses on scientific and methodological experience and the possibilities of organizing integrated resource and environmental mapping, studying and evaluating various types of technogenic resources, including those contained in them especially valuable (rare and noble) and environmentally limited toxic components (Be, Hg, As, Cd, Tl, etc.).

The portfolio of Russian technological developments is quite sufficient for an accelerated program-targeted solution of urgent problems of their implementation in order to clean up land use territories from stored production and consumption wastes and thereby eliminate one of the main causes of endemic environmentally caused morbidity and premature mortality of the population.
At the same time, the authors do not exclude the need to involve foreign technologies and experience in solving the problems under consideration as a successful elimination of negative environmental impact industrial and domestic activities and their prevention using the best available techniques (BAT). In this regard, the information basis of our publication was the recently appeared materials of specialists in the field of recycling, that is industrial processing and use of secondary raw materials. Like comparative analysis domestic and foreign developments seems necessary for a radical solution to the problem of MSW processing in our country.
In the meantime, of real actions, it is worth noting only the personal initiative of the President of the Russian Federation to eliminate scrap metal dumps accumulated and abandoned by the military on the Arctic coast, including barrels with unused fuel and lubricants.

Russian panacea: everything in earth
The vast expanses of our country, the traditional specifics of the mentality of the population, the lack of the necessary and intelligible public policy in the improvement of production and consumption waste management systems, including the radical improvement of the regulatory and legislative framework, led to the preferential disposal of solid waste in landfills both in the USSR and in new Russia. By the mid-90s, their number exceeded 35 thousand. At the same time, the annual volumes of solid waste taken into account when exporting from cities amounted to 35 million tons, that is, 260 kg / person. in year. In total, more than 65 billion m3 of MSW have been accumulated at registered landfills and landfills in Russia, with annual receipts since the mid-2000s of about 200 million m3 and a growth rate of 2% per year, which requires an increase in landfill areas by 2.5–4%.
According to experts of the Ministry of Natural Resources and Ecology of the Russian Federation, there are 110 thousand unauthorized dumps in Russia, the accounting, evaluation and elimination of which is an independent problem. In the period 2011-2014, the Ministry of Natural Resources of the Russian Federation eliminated 54,000 such illegal landfills, which is clearly not enough, given the continuous growth in their number. According to the estimates of the Accounts Chamber, the number of MSZ and MPZ operating in the country should be tripled, that is, we are talking about creating an industry for processing both household and industrial waste. Therefore, the tasks of greening existing industries and public utilities require their simultaneous commercialization through the use of the best available technologies for the elimination of both current and stale waste.
In Soviet times, there was an organized collection and consumption system for waste paper, textiles, food waste and scrap metal. Currently, such initiatives belong to a few private small environmental technology enterprises (METI) in some major cities(Moscow, Cheboksary, Vologda, Murmansk, etc.), whose activities are local in nature and not integrated into any system. Moreover, an unfounded opinion has formed in the media about the inapplicability of the systems of separate collection of waste and processing of domestic waste in Russian reality, which is not properly refuted by environmental authorities, including examples from foreign industrialized countries (Germany, Japan, the USA, etc.).

Many solid waste landfills and landfills have been created and operated without proper control of municipal and environmental authorities, with serious technological violations and beyond the operating life provided for by the projects, including in Murmansk, Vladimir (until 2000) and other cities. Large metropolitan areas are expanding the areas of export and disposal of their solid waste at the expense of neighboring administrative territories, thereby reducing their recreational potential. In particular, today there are more than 100 official landfills and landfills around Moscow alone (more than 10 in the Moscow suburbs alone), and the existing waste incineration plants cannot cope with the accumulated volumes of solid waste. The volume of annual removal of solid waste in the Pushkinsky district alone is ≥360 thousand tons. In addition, in the Moscow region, the amount of own industrial and domestic waste, as well as unauthorized landfills, including those enriched with elements-toxicants of the 1st hazard class - mercury, lead, cadmium and others, as well as radioactive elements and highly toxic organochlorines (PVC, etc.). All these landfills, which are not equipped in accordance with the best foreign experience with geomembrane systems for waterproofing, drainage and accumulation of wastewater and biogas (methane) formed due to the decomposition of biomass, are dangerous centers for the spread of environmental ill-being - from chemical and bacterial pollution of the environment and before. total groundwater to accumulations of stray dogs, rats. In addition, buried garbage is prone to spontaneous combustion, the elimination of which is no less difficult than fires in peatlands. The creation, arrangement and maintenance of landfills, as well as the allocation of land for them, are a heavy burden both on the budgets of municipalities and megacities: the disposal of 1 ton of garbage in developing countries costs 20–60 dollars, and in industrialized countries it is even more expensive.
The JIHT RAS has developed a radical method for volumetric sealing of solid waste landfills (landfills). For these purposes, it is proposed to use the ability of a new effective aluminosilicate reagent (ASR) - a flococoagulant - to turn from a sol solution into a gel and a solid colloid with a polymer matrix structure within 1–50 hours. Technologies have been developed for the continuous preparation of ASR and its injection into the body of a solid waste landfill through a network of boreholes. At the same time, the reagent displaces water from the entire volume of the MSW storage facility processed by it due to its greater density. Further hardening of the ASR turns MSW into a monolith, that is, it provides reliable sealing of the landfill and its isolation from any external influences. At the same time, the exclusion of internal fires of MSW and any water discharges or leachates to the relief is achieved. The JIHT has created an installation for the preparation of ACP and a model aquarium for a visual demonstration of the process of volumetric sealing of the MSW standard. The development in the mid-2000s was proposed for implementation when discussing options for the disposal of urban landfills in Sochi and Kuznetsk, where traditional engineering and construction solutions were preferred to an innovative technical solution to the problem of reliable disposal of solid waste. At present, the authors recommend using these developments for reliable isolation from the habitat of landfills in the Moscow region.
In the foreign world, unlike in Russia, as an alternative to MSW disposal, industrial waste incineration, separate collection, sorting and processing of urban waste, that is, their recycling, are widely used. Total In 1996, there were 2,400 such complex thermal enterprises in the world, and 2,800 by 2005. The leading role in their creation and technical improvement belongs to Germany as a leader in environmental technologies (21%) and the birthplace of recycling, which in the 1990s was carried out there more than than 160 factories. In Japan, the number of such enterprises in the same years was 49. As a result of a skillful combination of purposeful state policy and the interests of private entrepreneurs, up to 75% of solid waste is processed and destroyed in the MPZ and only 25% is buried. In Germany and Holland, up to 50% of MSW is processed and destroyed at thermal enterprises, in France - 40%, in Spain and the USA - 30-35%, in Italy, Canada, Poland - from 10 to 30%. At the same time, the cost of waste heat treatment at industrial enterprises in developing countries is $150–200/t, while in industrialized countries it is much higher. However, the overall economic efficiency, as well as compliance with national and international requirements environmental safety led to the predominant development of industrial waste processing and incineration compared to the outdated disposal of solid waste in landfills and landfills. Preventive “suppression” of production and consumption waste, including MSW and emissions, has been proclaimed as the main principle of the UN global program through the use of new technological processes that conserve natural resources, allow the use of secondary raw materials and materials, and thereby ensure resource and energy saving and environmental safety. In accordance with this program, France and the Netherlands reduced the volume of MSW disposal from 50 to 7% in the period from 1998 to 2000, while the share of incineration in France increased from 40 to 65%, and in the Netherlands - from 10 to 20% with increase in the volume of secondary use and processing (recycling) of useful components of MSW from 50 to 70%.

From the agricola picking table to the conveyor belt
One of the main operations in the technologies for the disposal of municipal solid waste in Russia and many countries is manual sorting. The idea of ​​this technology appeared at one time during manual ore sorting. The drawing of the first recognized European geologist, miner, metallurgist George Agricola shows the idea of ​​this technology: from a fixed table on which the ore mass is located, medieval workers dressed in leather aprons select useful minerals. In trays, useful and useless components are transferred to wooden barrels (containers).

This technology is designed for color vision and the agility of sorters (Klauber, German - "Krokhobor"), is currently carried out on moving belt conveyors of many waste processing complexes in Russia (there are over 250 of them today). The difference between the modern sorting belt and Agricola's engraving is only in its mobility and in the use of plastic containers instead of wooden buckets. The visual evaluation of the components, their classification, separation and selection have been and remain the constituent elements of manual sorting on a fixed Agricola table or on a modern conveyor moving at a speed of no more than 0.5 m / s.
Despite the creation comfortable conditions for MSW sorters, which allow them to select and send to containers up to half a ton of paper, up to 800 kg of glass containers, 280 kg of plastic, 55 kg aluminum cans per hour, manual sorting seems to a certain extent an anachronism for large inventories, but is indispensable for small and medium-sized METPs. It allows you to solve two interrelated tasks - economic and environmental: selective processing of MSW components with the production of secondary materials and the removal of highly toxic components from the unsorted mass subject to heat treatment at the MSZ and MPZ, which include mercury (fluorescent lamps), lead (batteries) , cadmium (accumulators, batteries and plastics) and other elements of three hazard classes, as well as organochlorine compounds, mainly associated with polymeric materials of the 1st hazard class. Separate collection of solid waste by type from the urban population, institutions and enterprises has long been widely practiced in Germany, the USA, France and other industries. developed countries, including the former USSR, ensuring the high quality of the materials obtained from them. However, at the same time, no more than 15–20% of the total MSW mass is involved in processing. Mechanized enrichment and sorting of solid waste entering thermal enterprises for processing and incineration in volumes from 100–250 thousand tons to 0.5–1.0 million tons per year is much more productive, but does not provide the necessary purity of the allocated recyclable materials and, therefore, the quality of the secondary materials obtained from it. At the same time, it is possible best options combinations of manual sorting of MSW (after pre-drying) on ​​a conveyor belt “before the furnace” with their mechanized sorting, and “after the furnace” for crushing and separating slag and ash with the separation of fractions of ferrous and non-ferrous metals.
Preliminary sorting of MSW with removal and removal of non-combustible materials to landfills reduces emissions of mercury during their heat treatment by 76%, arsenic - by 72%, lead - by 41%, and the combustion efficiency, on the contrary, increases by 22%.

Aeroseparation is one of the cheapest ways to sort MSW
For almost 500 years, has humanity managed to come up with something that allows you to get away from this labor-intensive, still living primitive? The answer can be considered positive. Aeroseparation is the separation of household waste in an ascending air stream. There are many designs of air separators that take into account the morphology, material and particle size distribution of MSW.
In the light fraction of aeroseparation, a mixture of polyethylene (PET) and polyvinyl chloride (PVC) plastics is of great practical interest. This is also important from an environmental point of view. If the organic part is sent for incineration, then the release of chlorine during the combustion of a mixture of plastics will lead to an excess of its content in the exhaust gases. A flotation method for the separation of PET and PVC is proposed. The crushed mixture of plastics is processed with a quebraccho or arabic gun depressor and, with the addition of a foaming agent, pain oil is fed into the flotation cell. When air is introduced into the chamber, particles containing PVC float into the foam, thereby separating from PET. However, more interesting is the dry method of separating these plastics by electroseparation, which is technologically and economically well combined with air separation. The purpose of this operation is to reduce the PVC content from 0.1 to 0.004%. The crushed mixture of plastics enters the tribochamber, where, due to mutual friction, PET and PVC particles receive different electric charges. In the EKS electric separator from Hamos GmbH (Germany), which has two flat plate electrodes, in a high-intensity field, positively charged PET particles are attracted to the negative electrode, give it their charge and are released from the apparatus in the form of a finished product.

If burned, how?
One of the most ancient methods of waste recycling, which is still used today both at the household level and in industrial scale, is their combustion. But when burning household waste containing a significant amount of polyethylene packaging, especially environmentally harmful PVC, a large amount of dioxins and furans, which are carcinogens, is released. This danger can be combated by organizing an efficient combustion mode in the furnace and by installing a sufficient number of exhaust gas purification stages. In Europe, this problem, in principle, has been solved. There are more than 400 plants in the European community that burn about 59 million tons of MSW per year, which generate 22 billion kWh of energy per year to supply the plants and cities themselves. At the same time, the problem of processing toxic ash and slag from MSW incineration is solved. In 1996, 11 million tons of MSW were incinerated at 51 waste incineration plants (ITW) in Germany. At the same time, up to 3 million tons of slag-ash waste (SHZO) were formed, of which 70% were subjected to enrichment. These SHZOs contained 50 to 90% mineral fractions, 1 to 5% carbon, and 9–10% metals.
The number of incinerators in Germany increased from 70 in 2007 to 85 in 2013, i.e. by more than 20%. Technologies alternative to incineration are also used there: sorting, mechanobiological processing followed by fermentation or composting of the biological part of MSW, etc. Nevertheless, it is widely believed that there is no alternative to incineration of MSW. Partial replacement of natural fuels (gas, oil, coal), in which the content of harmful impurities is higher than in MSW, with household waste is, according to the authors, environmentally preferable.
In recent years, a large amount of scientific and technical research has been carried out in different countries of the world and practical work on the creation of thermal power plants using household waste as fuel. There are designs of combustion chambers, exhaust gas purification systems, which allow achieving the energy and environmental efficiency of the MSW incineration process and the production of electricity from them, which are not inferior to the world level. The Fisia Babkok Environment GmbH concern has developed and put into operation an MSZ with a capacity of 360,000 tons of MSW per year. At the same time, the enterprise provides levels of emissions of harmful gases into the atmosphere, including dioxins and furans, an order of magnitude lower than the MPC, and metals extracted from slag can be sold in the amount of 4 million euros per year. It is indicated that the specific capital and operating costs with a guarantee of high environmental performance are significantly lower than at existing installations for the processing of solid waste. The concern is ready to supply dozens of installations in the Russian Federation and organize the disposal of solid waste.
In Russia, out of 35–40 million tons of MSW generated annually, only 4–5% are recycled. The rest are sent for deposition, in other words, for burial, as in ancient times. The total capacity of the seven largest Russian incinerators is about 1 million tons per year. There are three incinerators in Moscow, four more or less powerful incinerators operate in Vladivostok, Cherepovets, Pyatigorsk and Murmansk.
At a number of incinerators, solid waste is manually sorted on a conveyor belt, which allows, for example, at Incinerator No. 4 in Moscow, when processing 275 thousand tons of solid waste, to receive 10 thousand tons of paper and cardboard, 4 thousand tons of plastic, 3 thousand tons of glass, 7 thousand tons of ferrous and 1 thousand tons of non-ferrous metals. Waste after sorting is sent for incineration. The slag formed after incineration is used in road construction, and the ash is treated with hardeners, after which it is deposited. However, not all incinerators use sorting of waste before incineration. The separation of plastics from the stream before combustion is considered unprofitable, since the material supplied for combustion must have a certain calorific value in order for the production of steam and electricity to be economical.
In this case, it turns out that incinerators designed to solve environmental issues while burning plastics, including PVC, which are a major source of highly toxic dioxins and furans. Many incinerators are in long-term operation and use outdated technologies, which are especially detrimental in terms of off-gas cleaning. As good example solutions to the problem of reducing the concentration of harmful substances in the waste gases after combustion can be found in MSZ No. 3 in Moscow. The plant was commissioned in 1984. In 2012, it was reconstructed with the participation of an investor - the Austrian concern ENV AG - to achieve a capacity of 360 thousand tons of MSW per year. Thanks to the use of a combustion chamber of a new design, it was possible to ensure almost complete combustion of waste with an underburning of no more than 1%. Three-stage flue gas cleaning ensures the concentration of pollutants below 60% of the MPC, and the content of especially harmful dioxins and furans does not exceed 45% of the MPC. Magnetic separation of ash and slag waste provides up to 5 thousand tons of ferrous metal, the sale of which replenishes the plant's income.
Despite the assurances of the supporters of the technology of incineration of household waste in its environmental friendliness, there is a broad public movement in the country against the construction of an incineration plant in Moscow, St. Petersburg and other settlements. It comes to the fact that the protesters are chaining themselves to the fence of the places where it is planned to build such, from the point of view of the residents, industries that are detrimental to humans.
Waste incineration was initially considered as an alternative to MSW disposal. AT former USSR 10 incinerators operated, including 3 in Moscow and one each in Murmansk, Nizhny Novgorod, Vladivostok, Cherepovets and other cities. All of them turned out to be energy-intensive and do not produce any products, except for steam due to thermal energy, that is, unprofitable and subsidized. The cost of recycling 1 ton of MSW at the incinerator is now 220-240 rubles/ton, which is more expensive than all other methods of processing, and even more so - waste disposal. Currently, these incinerators are either stopped and reconstructed into waste processing plants - MPZ (Moscow), or continue to work according to the previous scheme (Murmansk), representing, unlike landfills, active and environmentally hazardous sources of environmental pollution. Waste incinerators were built in the early 1980s. Their equipment, mainly Czech (Dukla), is morally and technologically obsolete and does not provide both the high temperature of waste incineration (more than 1300 ˚С), necessary for the decomposition of highly toxic organic matter (dioxins, furans, etc.), and the multi-stage purification of waste gases (6 thousand m3 per 1 ton of MSW), currently accepted abroad. In our country, waste incineration occurs in one stage, abroad - in 5-6. Rationing of emissions at Russian incinerators is based on a limited number of pollution ingredients.

The results of special studies by the SZ STC "Ecology and Resources" of the activities of the Murmansk solid waste plant in 1997-98 indicate a complex and extremely dangerous impact of the enterprise on the environment in the Northern region of Murmansk, which occupies about 30% of the city area. In fly ash, slag and old slag-ash waste, high concentrations of a number of heavy metals of all three hazard classes were found, and the most significant excesses over the MPC normalized for soils were established for lead and zinc (up to 100–150 times), cadmium (100–1300 times), antimony, copper, chromium (from 3 to 30 times) and vanadium (1.3–7 times). Relative to the general sanitary hazard indicator, these concentrations exceed the standards for copper by 200–300 times, for zinc and lead by 80–100 times, and for vanadium by 1.3–6.7 times. In MSZ wastewater after washing the slag, concentrations of Cr, Ni, Cu, oil products, phenols, nitrogen dioxide, chlorine and sulfate ions exceed the MPC for domestic sewage. As is known, the presence of phenols and chlorine in wastewater causes the formation of dioxins in them, primarily characteristic of gas and dust emissions from incinerators, where their concentrator is fly ash. In the wash waters of the Murmansk MSW plant, concentrations of mercury were found to exceed the MPC by 8 times, cadmium and lead by 2–4 times, zinc and copper by 148–165 times, iron, nickel and cobalt by 5–10 times.
For decades, the Murmansk MSW MSW plant, which annually burned 100 thousand tons of MSW, in addition to polluting the atmospheric air in the city, practiced dumping slag-ash mixtures of various construction sites and, above all, garages, the official export of these mixtures to city ​​dump and, finally, unauthorized export to the green zone with dumping in the upper reaches of small rivers draining urban areas and flowing into the Kola Bay. Repeated attempts by the administration of the city of Murmansk, which sold its share of shares to private owners of the plant, to suspend its environmentally hazardous activities, met with resistance from the owners of the enterprise and an avalanche-like increase in the number of unauthorized dumps.

MSW recycling abroad and in Russia
According to foreign experience, at least 25-30% of the garbage, if it is pre-sorted, is subject to recycling, that is recycling with obtaining various valuable materials and products. For example, recycling of 1 ton of waste paper saves 3.5 m3 of wood, 6.3–14.6 GJ of heat, 300–800 kWh of electricity and reduces environmental pollution. In Germany, the motto "Here thanks for the garbage" has become one of the incentives to replace natural wood imported from Scandinavia with recycled packaging materials. In the same place, for the annual production of 10 billion packaging bags, more than 0.2 million tons of cardboard material is spent, that is, 2.5 kg per inhabitant. In the two years since the government decree on recyclable packaging, garbage disposal in landfills has decreased by 15%. Up to 95% of cardboard packaging is selected on the sorting belt. Recycling enterprises are equipped with computers, infrared metal detectors, vibration separators and other mechanical, optical and electronic devices.
In Russia, ShZO volumes waste incinerators make up about 30% of the initial mass of MSW. According to calculations based on the results of experimental fractionation of ShZO at Moscow MSZ, due to the processing of the entire volume of solid waste (2.5 million tons / year), it can be obtained: glass-ceramic mass - 123.7 thousand tons, iron scrap - 33 thousand tons, aluminum - 3.95 thousand tons, copper -
1.7 thousand tons, magnetic and slag sand - 371.2 thousand tons. Heavy metal concentrate contains 37% copper, 12.6% zinc, 4.3% lead and corresponds in quality to recycled copper class G grade 1 (GOST 1639-78). The aluminum content in the light fraction (after regrinding) is 50–60%, which meets the requirements of the same GOST for raw materials for the production of secondary aluminum. All operations for the processing of SHZO are carried out using simple equipment (ferrous scrap press, crusher, vibrating screen, magnetic separator, jigging machine). As a result, the need for removal, storage or disposal of bulk slag-ash waste is eliminated, another direction of small environmental business is created, and the requirements of environmental and sanitary safety in waste management of MSZ and MPZ are observed.
It should be noted that all domestic developments of industrial waste processing technology proposed in the last 25 years have remained unrealized. To a certain extent, this was due to the developers borrowing waste incineration technologies from their own field of activity - metallurgical (blast furnace), energy (power plant boiler), defense and others that do not take into account the specifics of MSW heat treatment and have not yet been experimentally confirmed. On the other hand, when using foreign technologies, the specifics of the composition and condition of Russian solid waste were not taken into account, which differ significantly from Western standards in unsorted, high humidity, low thermal conductivity, high ash content (up to 30%), etc. Often, the consent of Western partners to provide loans for the creation of a refinery in Russia was accompanied by conditions for the import and incineration of foreign waste on them. Domestic projects for the construction of waste processing enterprises provide for a payback period of 3.5–5 years with a specific investment rate per 1 ton of solid waste of about $190.3. Abroad, this figure is much higher: in the Netherlands - $417, in the USA - $450 dollars, in Germany - 715 dollars. The cost of Western MPZ projects, as a rule, exceeds the financial capabilities of the regions of Russia, with the exception of Moscow, where a city network of waste transfer stations has been created; Using foreign technologies and equipment, waste is pressed into briquettes, which makes it possible to reduce the volume of SDW taken to suburban landfills (in Iksha, Khmetyevo, etc.) up to four times, to ensure maximum loading of garbage chutes and thereby save money on vehicles and volumes of waste disposal.
In order to implement such a policy, GUP Ecoprom and MGUP Promotkhody were created in Moscow, and the latter united 16 commercial organizations employed selective collection and recycling of secondary raw materials, mainly industrial enterprises and the non-residential sector, using domestic technologies and equipment. Particular attention is paid to the restoration of the market for the collection and recycling of waste paper, which was lost in the 1990s. Its blanks in Moscow for recycling then amounted to 350 thousand tons, in the Moscow region - 75 thousand tons. This waste paper was exported for processing to the cities of Stupino and Serpukhov to paper mills (2–4%), and the rest to Leningrad, Ryazan, Murom and other cities due to the lack of such industries in Moscow. At 52 enterprises, using waste paper (from 20 to 100% of the load), 50 types of paper and cardboard were produced. As you know, the targeted collection of waste paper was organized centrally throughout the country.
In the 2000s, a number of private firms were established in Moscow for the processing of secondary raw materials: waste paper, mercury lamps, lead batteries, galvanic sludge and electroplating waste, car tires, etc. In addition, numerous areas of radioactive contamination are found at urban construction sites and unauthorized dumps: NPO Radon annually identifies 10-15 such sites when digging foundation pits throughout the city.
Despite substantial investments (hundreds of millions of dollars) in the construction and reconstruction of waste disposal and recycling facilities in Moscow, up to now, up to 90% of urban waste has to be removed and buried in landfills and landfills in the Moscow Region. The problem is exacerbated by the annual formation in Moscow of another 6 million tons of industrial waste and more than 1 million tons of sludge from sewage treatment plants contaminated with heavy metals and toxic organics, the accumulation of which amounts to tens of millions of cubic meters.
In limited volumes (up to 10%), MSW processing is carried out in Nizhny Novgorod, Ufa and St. Petersburg. It is noteworthy that in the latter case, biothermal technology is used, which is based on the principle of converting the organic part of MSW, which is about 40–50% (food waste, wood, waste paper, etc.), into compost with the removal, pyrolysis treatment and disposal of non-compostable components. However, the high content of non-removable heavy metals and other toxicants in the compost sharply limited the possibilities for agricultural use of such compost, as well as the sludge from urban sewage treatment plants.
According to the rich foreign experience and domestic developments of enthusiasts, any biomass under certain conditions can be processed into biogas (methane), which is released in abundance during the decomposition of solid waste in landfills and landfills, during the storage of compost and manure, etc. Biogas can be obtained as at small-sized installations for autonomous heat and energy saving in urban and rural conditions, and at large plants located at landfills and solid waste dumps. The world leader in the creation and wide use of bioenergy plants is China, where about 5 million home biogas plants operate, producing more than 1 billion m3 of gas per year for 20 million people. Up to 0.5 million bioenergy installations (BEU) are used in India, hundreds of them are estimated in Japan, Europe and America.
In the US, more than 30 large plants extract methane from the decomposition products of urban landfills.

In our country, up to 500 million tons are produced annually organic waste(by dry matter), which is equivalent in terms of energy content to 100 million tons of standard fuel. For the first time, back in 1940–1950, the ideas of biotechnological processing of organic waste were put forward in the USSR, but until recently, only one such installation was operating at the Oktyabrskaya poultry farm in the Moscow region, and the second was tested at a poultry farm in the Vladimir region. Then the EcoRos center designed two serial biogas plants: IBGU-1 for a peasant estate and BIOEN-1 for a farm. Their testing and operation have proven a triple effect: environmental (destruction of biomass waste), energy (methane production) and economic (production of non-traditional, environmentally friendly and highly effective fertilizers from the remnants of processed biomass). In terms of efficiency, 1 ton of new fertilizers is equivalent to 60 tons of manure. The annual productivity of BEU as a fertilizer factory reaches 70 tons at a consumption of 1 ton per hectare of land. The first 65 BEU of the estate type were produced by factories in Tula and Kemerovo region. The need for farmstead BEU is determined for the next 5 years at 50 thousand units. at a cost of 20 thousand rubles. Orders for Russian plants came from Kazakhstan and Belarus, South Africa, the United Arab Emirates, Denmark, Finland and even China, the world's leading biogas producer.

Experimental pyrolysis plants for the processing of various types of biomass, including wood, have been created in Canada, Italy, Spain, Finland, the Netherlands, the USA and Greece, and researchers and their creators are united in the Pyroysis NetWork (PyNe) Pyrolysis Network, whose work is funded by European Commission. The most "advanced" are the Canadian installations of the Ensyn company, which are also used in the USA and Great Britain. Pyrolysis of biomass, including specially grown wood, is considered as one of the priority areas of energy in European countries.

Is there any prospect of using "wet" methods of MSW processing?
A message appeared on the Internet about a radical change in the direction of waste disposal towards the use of hydroseparation. It is also known that in Pyatigorsk, options for the reconstruction of the existing WIP were discussed. Niagara Trading Co. Ltd has proposed a hydrothermal method for processing Waste Away MSW. The garbage turns into a homogeneous, biologically stable material, the so-called fluff. It is pressed and can be used as an alternative fuel, fertilizer or in construction. This method is practically waste-free. However, the city leadership, avoiding the risk, since the Waste Away method is not yet widely used, decided in favor of the incineration technology proposed by CNIM. There are reports on the Internet that the authorities are refusing to build plants for burning household waste. There is no certainty that the construction of new WIPs in Moscow and other regions of the Russian Federation will take place. As an alternative, hydraulic methods for processing MSW are called, although the details of these methods are not specified.
In our opinion, one of such alternative methods to incineration can be the technology of mechanobiological processing of MSW (MBP MSW), developed by Hese GmbH (Germany). The technology is implemented in several interconnected modules. At the head of the process is the “Enrichment” module, the task of which is to separate metals, inert materials (stones, ceramics, etc.) from MSW, as well as a biological part for the production of alternative fuel and raw substrate for pelleting or sending to a composting or fermentation module.
The basis of the “Enrichment” module present in all combinations is the cascade mill. In the mill, MSW is crushed with metal balls. The maximum size of objects and pieces of solid waste entering the mill is determined by the diameter of the mouth (1 m). Items larger than 1 m are removed before entering the mill. Foil, organics, paper, cardboard, food waste falling between the balls are crushed to a particle size of 10–40 mm. Biological components are crushed, while metal objects, batteries, plastic bottles are only deformed. Organic components (food waste), the content of which is slightly more than 5%, are crushed to 25–40 mm. In this case, the yield of fractions from 0 to 10 mm is 80–85%. These fractions, crushed and disintegrated, are saturated with oxygen, which contributes to their subsequent fermentation or composting. At the outlet of the cascade mill there is a butara (drum sieve), in which the separation of the finely divided biological phase is carried out. The fraction larger than 40 mm after butara is subjected to magnetic separation to separate ferrous metals and then to extract non-ferrous metals in an electrodynamic separator. A fraction smaller than 3–8 mm has high humidity, which is very favorable for subsequent fermentation or composting processes. With a plant capacity of 120 thousand tons of MSW, with three-shift operation, in 250 working days the plant provides: 6 thousand tons of iron-containing products, 0.4 thousand tons of non-ferrous metals, 14 thousand tons of EBS 1 fuel substitute (contains viscous plastics); 65 kt of EBS fuel substitute, 2.29 kt of fines (<5 мм) для биологической переработки, 5 тыс. т инертных материалов. Это означает, что технология механобиологической переработки обеспечивает более чем 90%-ное использование бытовых отходов!
The above materials testify to the need for a program-targeted solution to the problem of involving industrial and domestic waste in the processing throughout Russia with the creation of a new industrial sector. Not only the Arctic and near space need to be "cleansed" in accordance with the initiatives of the country's president and academicians. First of all, single-industry towns and densely populated areas should be involved in this process, where waste processing can activate the innovative and technological potential, provide employment for the population, improve its socio-economic status and reduce the levels of environmentally caused morbidity.
What does that require? First of all, the political will to improve the existing regulatory and legislative framework and the manifestation of initiatives in the organizational and financial support of scientific and techno-ecological developments and programs at the federal, regional and municipal levels. For these purposes, it seems appropriate to hold parliamentary hearings in the State Duma of the Russian Federation in 2016 and then special territorial conferences. As a result, a technological platform for a future action program can be created and an Interregional Coordinating Council (ICC) can be formed. The recommended organization of corporate interaction between environmental specialists, technologists and economists of the Russian Academy of Sciences, universities and enterprises that are directly related to the problem under consideration and thus already participating in its solution, is capable, for its part, of ensuring the implementation of government initiatives, up to the creation of network structures of scientific and industrial public-private partnership.
For its part, the editors of the Rare Lands magazine express their readiness to provide information support, including the exchange of organizational and technological experience between existing large and small enterprises engaged in waste disposal and recycling, primarily in Moscow and the Moscow Region with the assistance of the Ministry of Natural Resources and Ecology and the Ministry of Industry and Trade RF.

Scheme of X-ray separator by Mogensen (Germany)

An example of the use of X-ray sorting of municipal solid waste is the scheme proposed by the German firms Mogensen and CommoDas. The operating principle of the Mogensen separator is based on the use of X-ray irradiation of the material moving on the conveyor belt, separated after MSW air separation. When X-rays pass through pieces of material, the effect of their weakening is observed, which depends on the atomic structure and density of the material.
In samples of the heavy fraction of air separation with a particle size of 30–60 mm, organic and inorganic components are distinguishable. The advantage of this method, for example, over a separator operating in the near infrared region of the spectrum, is that the separation criterion is the density of the material. This criterion does not depend on the size of the particles, nor on their shape, weight, and surface color. Such subtlety of perception is inaccessible to the human eye.
According to the scheme, the separated material from the feed hopper 1 enters the transport tray 2, which doses the material and feeds it to the table 3, on which the particles are separated and a monolayer is formed. From source 4, the moving material is irradiated in the angle range of 80˚. The intensity of rays passing through the material is measured by two fast-line sensors with different spectral ranges. Specially designed for Mogensen, single-line sensors that, at 0.8mm resolution and 10-bit processing depth, match the speed and resolution of a single-line CCD camera when sorting by color. Classification of particles is carried out by the data processing device using the computer 6 within a few milliseconds. Based on the results of ultra-high-speed analysis of whether particles belong to one or another type, the computer transmits a command to device 7 equipped with high-speed pneumatic valves, which are analogous to the hand of the ore picker from Agricola's engraving.
Jets of compressed air blow off particles of organic and inorganic composition into compartment 8 with two containers. Mogensen manufactures two types of separators: AR 1200
and AQ 1100, with a solid waste capacity of 5 to 20 m³/h. Electricity consumption is 7.5 kW/h. When enriching municipal solid waste
get an organic fraction that can be used as an alternative fuel, and an inorganic fraction containing less than 5% organics, which can be
directed to the deposit. The separator is equipped with radiation protection, and the radiation level is well below the permissible dose of radiation.

Literature
1. Delitsyn L.M., Vlasov A.S. Immobilization of condensed hazardous industrial substances. On Sat. Technogenic resources and innovations in technoecology. Ed. EAT. Shelkov and G.B. Melentiev. - M: OIVT RAN, 2008. - S. 352.
2. Malyshevsky A.F. Substantiation of the choice of the optimal method for the neutralization of municipal solid waste from the housing stock in Russian cities. Ministry of Natural Resources of the Russian Federation, 2012. 3. Melentiev G.B. Creation of an industry for processing renewable technogenic resources and innovative technoecology as an alternative to extensive subsoil use. On Sat. North and Market. - Apatity: KSC RAS, 2007. S. 178-184.
4. Melentiev G.B. Technogenic potential: in anticipation of industrial development. Well. Rare Earths, vol. 3, 2014, pp. 132–141.
5. Melentiev G.B., Shulenina Z.M., Delitsyn L.M., Popova M.N., Krasheninnikov O.N. Industrial and domestic waste: innovation policy and scientific and industrial entrepreneurship as a means of solving the problem. Well. Ecology of industrial production, vol. 4, 2003 (part 1). pp. 43–54; issue 1, 2004 (part 2). pp. 41–51.
6. Shubov L.Ya., Stavrovsky M.E., Shekhirev D.V. Megacity waste technology. Technological processes in service, 2002, Moscow.
7.W.L. Kaltentindt, W.L. Dalmijin. Improved Separation of Plastics by Flotation Using a Combined Treatment. Freiberger Forschungshefte, A 850, 1999, Sortierung der Abfaelle und mineralischen Rohstoffe, Technische Uni Bergakademie Freiberg, s. 132–141.
8. P. Koch Die Rolle der Zerkleinerung in Anlagen zur mechanischbiologischen Abfallbehandlung von Hausmuell (MBA). Aufbereitungs Technik, 4, 2002/43. Jahrgang, s. 25-32.
9. P. Koch, W. Weining, B. Pickert Haus- und Restmuellbehandlung mit dem modularen Hese - MBA - Verfahren, Aufbereitungs Terchnik, 6, 2001/42. Jahrgang, s. 284–296.
10. R. Meier – Staude, R. Koehlechner "Elektrostatische Trennung von Leiter-/Nichtleitergemischen in der betrieblichen Praxis". Aufbereitungs Technik, 3, 2000/41. Jahrgang, s. 118–124. 11. G. Nimmel Aerostrommsortierung bei der Restabfallaufbereitung. Aufbereitungs Technik, 4, 2006/47. Jahrgang, s. 16–28.
12. T. Nisters. Ersatzstoffherstellung mit NIR - Technologie. Aufbereitungs Technik, 12, 2006/47. Jahrgang, s. 28 - 34.
13. T. Petz, Ja. Meier-Kortwig Aufbereitung von Muellverbrennungsaschen unter besonderer Beruecksichtigung der Metallrueckgewinnung. Aufbereitungs Technik, 3< 2000/41. Jahrgang, s. 124–132
14. A. Trogl. Was waere die Entsorgungswirtschaft ohne die Abfallverbrennung?. Aufbereitungs Technik, 5, 2007/48. Jahrgang, s. 4–13.
15. E. Zeiger Sortierung verschiedener Abfallstroeme mit Mogensen - Roentgen - Sortiertechnik. Aufbereitungs Technik, Nr.3, 2006, 47. Jahrgang, s. 16–23.

TEXT: Yu.V. Ryabov, G.B. Melentiev, L.M. Delitsyn
Joint Institute for High Temperatures RAS

1. The composition of the landfill

The MSW landfill is a complex of environmental structures designed for storage, isolation and neutralization of municipal solid waste, providing protection against pollution of the atmosphere, soil, surface and ground water, preventing the spread of rodents, insects and pathogens.

The landfill for municipal solid waste generally consists of the following parts:

Access road for delivery of solid waste and reverse movement of empty garbage trucks;

Economic zone intended for organizing the operation of the landfill;

Solid waste storage area, where waste is placed and buried; the storage area is connected to the economic zone by a temporary on-site road;

Power supply line from external electrical networks.

The waste mass of the landfill is limited by engineering structures: the top final cover and impervious screen to control landfill emissions - reducing adverse environmental impacts.

2. Requirements for the location of the landfill

The choice of a site for a solid waste landfill is carried out on the basis of the functional zoning of the territory and urban planning decisions; the latter are carried out in accordance with SNiP. Landfills are located outside the residential area and in isolated areas with the provision of the size of the sanitary protection zone.

Polygons are not allowed:

On the territory of I, II and III belts of zones of sanitary protection of water sources and mineral springs;

In all belts of the zone of sanitary protection of resorts;

In areas of mass out-of-town recreation of the population and on the territory of health-improving institutions;

In recreational areas;

In places where aquifers wedged out;

Within the boundaries of the established water protection zones of open reservoirs.

It is not allowed to place landfills in swampy and flooded areas. Areas where clays or heavy loams are found in the base are promising for the placement of landfills, and groundwater occurs at a depth of at least 2 m. At the same time, the base soils should have a filtration coefficient of no more than 10 cm / s (0.0086 m / day.) .

The selected site for the landfill should have a sanitary and epidemiological conclusion on compliance with its sanitary rules.

3. Protection of the base of the solid waste storage area

For base soils with a filtration coefficient of more than 10 cm/s, the following impervious screens must be provided:

1) a single-layer clay screen with a thickness of at least 0.5 m. The initial clay of an undisturbed structure must have a filtration coefficient of not more than 0.001 m / day. A protective layer of local soil with a thickness of 0.2 ... 0.3 m is laid on top of the screen;

2) a ground-bitumen screen treated with organic binders or waste from the oil refining industry with a thickness of 0.2 to 0.4 m on one side or double impregnation with a bitumen emulsion, depending on the composition of the waste and climatic conditions;

3) two-layer latex screen. The screen consists of a 0.3 m thick planning underlay, a latex layer, an intermediate layer of sandy soil 0.4 m high, a second layer of latex and a protective layer of fine-grained soil 0.5 m thick;

4) screen made of polyethylene film, stabilized with soot, two-layer. A two-layer screen consists of an underlying layer - clay soil with a thickness of at least 0.2 m, two layers of polyethylene film stabilized with soot, 0.2 mm thick. Between the layers of the film, a drainage layer of coarse-grained sand 0.4 m thick is arranged. A protective layer (0.5 m thick) of sandy soil with particles of maximum size up to 5 mm is laid on the top layer of the film. It is allowed to use single-layer artificial screens without filtrate drainage under favorable hydrogeological conditions of the storage area: the groundwater level is not less than 6 m from the base surface of working charts; the presence at the base of the maps of loams with a filtration coefficient of no more than 10 cm/s and a thickness of at least 6 m.

The drainage layer is provided for emergency situations and control of the leachate outlet.

5) SS100 bentomat screen. The soil on which the material is laid must be compacted with a compaction coefficient of at least 0.9. The base should not contain plant roots, stones and other objects that can mechanically damage the material. All irregularities in the base larger than 12 mm must be leveled. The amount of material laid on the site daily should be such that it can be covered on the day of laying with a protective layer of soil. As an exception, the movement of the wheeled vehicle on the laid mats is allowed, avoiding mechanical impacts on the material during sudden stops. The bentomat is protected by a layer of fine-grained soil with a layer thickness of 300 mm. The bentomat panels 5 m wide and 40 m long are overlapped by at least 150 mm. To provide additional reliability between the overlapped edges, bentonite granules are poured in an amount of 0.4 kg / linear meter.

4. Drainage system

The drainage system is designed to collect and remove the leachate. One of the designs of the drainage system is as follows. A material with a low content of lime, particle size 16 ... 32 mm and a filtration coefficient of more than 10 m / s, is applied to the layer of non-woven textiles above the polymer fabric, acting as a return filter. The layer thickness is at least 50 cm.

In the area where the filtrate discharge pipes are located, the layer thickness increases to 105 cm (three diameters of the filtrate discharge pipe). This ensures that the pipe is adequately protected.

The return filter is poured at the beginning and distributed over the protective sheet with the help of light equipment. Pipes are laid in a straight line with a stop angle of 120°.

To ensure that the filtrate is removed from the entire area, the return filter has a slope of more than 3% in the direction of the pipes for collecting the filtrate. The maximum runoff length of the filtrate from the surface filter is 15 m. It follows that the maximum distance between the filtrate collectors is 30 m.

The leachate is collected at the lowest point of the landfill using PEHD pipes (according to the Russian classification - from polyethylene pipes PE 80 SDR technical according to GOST 18599-2001).

Drainage pipes are made with perforation (slots) across the pipe axis for 2/3 of the pipe perimeter. The area of ​​the slots must be at least 5% of the outer surface of the drain pipes. The slot width is 12 mm, the slot length is 60 mm, which protects them from clogging when using a return filter with a particle size of 16 ... 32 mm. Pipe ends are not perforated when pipes pass through the enclosing embankment.

In the direction of leachate flow, the drainage pipes pass through the landfill embankment and slope cover and enter sewer wells located outside the landfill field.

On the opposite slope, drainage pipes are led upwards along the polymer layer from the storage area for control and washing. At the edge of the slope, the drainage pipes end. They are closed with an airtight cap, dismantled for technical revision. With this design, access to the filtrate collectors from two sides is possible, as well as the possibility of washing and using a mobile chamber.

Controlled pipes (pipe-in-pipe system) should be used in the area where drainage pipes are laid through the embankment. The support of the pipe at the point of passage through the embankment must be made in such a way that no water leakage occurs in this place.

After the drainage pipes are removed from the storage area in the sewer wells, they are combined into a common (sewer) pipe with a discharge to the filtrate collector.

If necessary (according to the altitude conditions of the area), a pumping station can be installed into which the filtrate is collected. From the pumping station, the filtrate is pumped into the collection.

The filtrate collected by the sewerage system can be removed by means of a pumping station to the district treatment plant. Part of the filtrate can be supplied to the storage area for moistening of solid waste during a fire hazard period using a pumping station.

5. Economic zone

5.1. Composition of structures

On the territory of the economic zone are located:

Administrative building (ABK);

Checkpoint (checkpoint) together with the point of stationary radiometric control;

weight;

Garage and platforms with sheds and workshops for parking and repair of machines and mechanisms;

Warehouse of fuels and lubricants;

Warehouses for the storage of energy resources, building materials, overalls, household equipment, etc.;

Power supply facilities;

Garbage truck washing;

fire fighting containers;

Disinfectant baths;

Wastewater treatment facilities for washing garbage trucks;

Sewer pumping station.

In the building of the administrative building there are social premises for employees (locker rooms, toilets, showers), a rest room, a dining room, a security room.

The territory of the economic zone must have a hard surface, lighting and entry from the side of the landfill.

At large landfills that accept over 360 thousand cubic meters. m / year of solid waste and designed for a service life of more than 15 years, technical water supply is provided from artesian wells located on the territory of the economic zone. Drinking water must be imported.

At smaller landfills designed for a service life of less than 15 years, in agreement with the authorities of Rospotrebnadzor and local municipal authorities, technical water supply is provided with imported water.

Waste removal is carried out using:

City sewerage system (if there is a sewer collector at an economically justified distance);

Control and regulation pond;

Evaporator pond.

The area of ​​the evaporation pond is determined from the estimated runoff of storm water from the area of ​​the landfill.

Near the economic zone, a parking area for cars of the landfill workers is arranged.

The number of parking spaces per 100 workers in 2 adjacent shifts is 7...10. This number should be adjusted in accordance with the level of motorization.

The territory of the economic zone is supplied with storm sewerage with discharge of effluents into the general sewer network.

The sewerage of the administrative and residential complex is designed with the collection of wastewater in septic tanks, from which the export to the city (district) treatment facilities is organized.

5.2. The main parameters of structures.

At the exit from the landfill, there should be a control and disinfection zone with a reinforced concrete bath 8 m long, 0.3 m deep and 3 m wide for disinfecting garbage truck wheels. The bath is filled with a three percent Lysol solution and sawdust.

Water consumption for external fire extinguishing is 10 l/s. A prefabricated reinforced concrete tank or fire extinguishing pond is designed with a capacity of at least 50 cubic meters. m and is determined by local conditions.

A fence is being designed along the perimeter of the entire territory of the solid waste landfill. The fence can be replaced by: a drainage trench with a depth of more than 2 m, a shaft with a height of more than 3 m. A gate or a barrier is designed in the fence of the landfill near the administrative building.

Drainage (upland) ditches are calculated to divert runoff from areas located above the landfill.

Outdoor lighting according to a permanent scheme is provided only for the economic zone, daily maps are illuminated according to a temporary scheme.

The minimum illumination of working (daily) cards is 5 lux.

6. Operation of the landfill

6.1. Basic technological operations.

The following main types of work are performed at the landfill: reception, storage and isolation of solid waste.

Accounting for accepted solid waste is carried out by volume in an uncompacted state. A note on the accepted amount of MSW is made in the MSW registration log.

It is strictly forbidden to dispose of waste suitable for use in the national economy as secondary resources, as well as toxic, radioactive and biologically hazardous waste to landfills.

The organization of work at the landfill is determined by the technological scheme for the operation of the landfill, developed as part of the project. The main work planning document is the operation schedule drawn up for a year. It is planned monthly: the number of accepted solid waste, indicating N cards on which waste is stored, the development of soil for solid waste isolation.

The organization of work at the landfill should ensure environmental protection, maximum productivity of mechanization equipment and safety precautions.

6.2. Control of delivered MSW.

The operation of the landfill, waste disposal, as well as the refusal to accept waste should be regulated by the regulations for the acceptance of permitted types of waste. In order to ensure that only permitted waste is deposited, control measures are required by the landfill staff.

The control of delivered waste includes the following:

Checking the carrier's accompanying documents;

Determining the volume and weight of waste;

Carrying out visual control;

Performing radiometric control.

Verification of accompanying documents and weight measurement are carried out at the entrance. Visual control, in which the brought waste is controlled by type, consistency, color and smell, is carried out during weighing and when unloading trucks. When in doubt, it is necessary to take samples of the brought material. Waste brought to the landfill that is not permitted for storage is not accepted.

6.3. Transport unloading.

Uninterrupted unloading of garbage trucks is organized at the landfill. Garbage trucks arriving at the landfill are unloaded at the work map.

The site for unloading garbage trucks in front of the working map is divided into two sections: garbage trucks are unloaded in one section, bulldozers or compactors work in the other.

The placement of garbage trucks at the unloading site should ensure the unhindered exit of each unloaded truck.

The duration of acceptance of garbage trucks for unloading at one section of the site is assumed to be 1 ...

The path from the scales to the place of unloading is equipped with signs. All cars move according to the signs in the shortest way from the scales to the storage area. Drivers are given the place of unloading. Machines must maintain a safe distance from the unreinforced edge of the slope - at least 10 m. After unloading and re-checking the lot, the machine immediately leaves the unloading site.

6.4. Waste disposal.

MSW unloaded from trucks are stored on the work map.

Random storage of solid waste is not allowed throughout the landfill area, outside the site allotted for a given day (work maps). The following dimensions of the work card are set: width 5 m, length 30 - 150 m.

Bulldozers move MSW onto the working map, creating layers up to 0.5 m high. Due to 5 ... 10 compacted layers, a shaft with a gentle slope 2 m high above the level of the garbage truck unloading area is created. The shaft of the next working card is "pushed" to the previous one (storage according to the "thrust" method). In this method, the waste is placed from the bottom up.

A compacted layer of MSW 2 m high is insulated with a soil layer of 0.25 m (if compaction is ensured by 3.5 times or more, an insulating layer 0.15 m thick is allowed). Unloading of garbage trucks before the working map should be carried out on a layer of solid waste, since the laying and isolation of which more than 3 months have passed. (as the maps are filled, the front of work recedes from the solid waste laid in the previous day).

Storage of MSW by the "pushing" method is carried out from top to bottom. The height of the slope should be no more than 2.5 m. With the "push" method, unlike the "thrust" method, the garbage transport is unloaded on the upper isolated surface of the working map formed on the previous day. As the maps are filled, the front of work moves forward along the solid waste laid down in the previous day.

The shifting of MSW unloaded by garbage trucks onto the working map is carried out by bulldozers of all types. To increase the productivity of bulldozers (by 30 - 40%), it is necessary to use dumps with a large width and height.

Compaction of solid waste laid on the working map in layers of 0.5 m is carried out by heavy bulldozers weighing 14 tons and based on tractors with a power of 75 ... 100 kW (100 ... 130 hp). Compaction in layers of more than 0.5 m is not allowed. Consolidation is carried out by 2... 4-fold passage of the bulldozer in one place. Bulldozers compacting MSW must move along the long side of the map. With a 2-fold passage of the bulldozer, the compaction of solid waste is 570 ... 670 kg / cu. m, with a 4-fold pass - 670 ... 800 kg / cu. m.

To ensure uniform subsidence of the landfill body, it is necessary (twice a year) to make a control determination of the degree of solid waste compaction.

Humidification of MSW in summer must be carried out during fire periods. Water consumption for irrigation is taken 10 liters per 1 cubic meter. m MSW.

Intermediate and final insulation of the compacted layer of MSW is carried out with soil. When storing MSW on open, non-buried pits, intermediate insulation in the warm season is carried out daily, in the cold season - with an interval of no more than three days. The intermediate insulation layer is 0.25 m, when compacting solid waste with KM-305 rollers - 0.75 m.

The development of soil and its delivery to the working map is carried out by scrapers.

In winter, it is allowed to use construction waste, production waste (waste of lime, chalk, soda, gypsum, graphite, etc.) as an insulating material. As an exception, in winter it is allowed to use snow supplied by bulldozers from nearby areas for insulation. In the spring, when the temperature rises above 5 °C, the areas where snow insulation was applied are covered with a layer of soil. Laying the next layer of solid waste on an insulating layer of snow is unacceptable.

6.5. Sanitary protection zone.

The sanitary protection zone (SPZ) separates the territory of the landfill site from residential development, landscape and recreational zone, recreation area, resort with mandatory delineation of boundaries with special information signs.

The sanitary protection zone is an obligatory element of the solid waste landfill. The use of SPZ areas is carried out subject to the restrictions established by the current legislation, norms and rules. The sanitary protection zone is approved in accordance with the established procedure in accordance with the legislation of the Russian Federation in the presence of a sanitary and epidemiological conclusion on compliance with sanitary norms and rules.

The width of the sanitary protection zone is set in accordance with SanPiN 2.2.1/2.1.1.1200-03. The width of the CVD of the solid waste landfill is assumed to be 500 m for a class 2 enterprise.

The territory of the sanitary protection zone is intended for:

Ensuring a reduction in the level of exposure to the required hygienic standards for all factors of exposure outside it;

Creation of a sanitary and protective barrier between the territory of the landfill and the territory of residential development;

Organization of additional green spaces providing screening, assimilation and filtration of atmospheric air pollutants and increasing the comfort of the microclimate.

The sanitary protection zone should have a consistent study of its territorial organization, landscaping and landscaping at all stages of the development of projects for the construction, reconstruction and operation of the landfill.

For an operating landfill, a project for organizing a sanitary protection zone should be a mandatory document.

As part of the project for the organization, landscaping and improvement of sanitary protection zones, documentation is submitted in an amount that allows assessing design decisions on compliance with their sanitary standards and rules.

The pre-project, project documentation for the construction of new, reconstruction or technical re-equipment of existing landfills should provide for measures and funds for the organization and improvement of sanitary protection zones, including the resettlement of residents if necessary. The project of organization, improvement and gardening is submitted simultaneously with the project for construction (reconstruction, technical re-equipment).

6.6. Monitoring system.

The monitoring system should contain:

organizational structure;

General model of the system;

Complex of technical means;

situation models;

Methods of observation, data processing, situation analysis and forecasting;

Information system.

A special monitoring project is being developed for the MSW landfill, which includes sections: monitoring the state of underground and surface water bodies, atmospheric air, soils and plants, noise pollution in the zone of possible adverse impact of the landfill; a system for managing technological processes at the landfill, which ensures the prevention of pollution of underground and surface water bodies, atmospheric air, soils and plants, noise pollution above the permissible limits in cases where the polluting effect of landfills is detected.

The MSW landfill monitoring project is developed according to the terms of reference of the landfill owner and coordinated with the authorized bodies.

The monitoring system should include devices and structures for monitoring the state of ground and surface waters, atmospheric air, soil and plants, as well as noise pollution in the zone of possible influence of the landfill.

In agreement with the hydrogeological service, local bodies of Rospotrebnadzor and environmental protection, control pits, wells or wells are designed in the green zone of the landfill to control the state of groundwater, depending on their depth.

One control facility is laid upstream of the landfill along the groundwater flow to collect water samples that are not affected by leachate from the landfill. Water samples from control pits, wells and boreholes laid upstream of the groundwater test site characterize their initial state.

Below the landfill downstream of groundwater (at a distance of 50 ... 100 m, if there is no danger of groundwater pollution from other sources), 1 - 2 wells (pits, wells) are laid for water sampling in order to identify the impact of landfill effluents on it.

Wells with a depth of 2 ... 6 m are made of reinforced concrete pipes with a diameter of 700 ... 900 mm to a mark of 0.2 m below the groundwater level (GWL). The filtering bottom consists of a layer of crushed stone 200 mm thick. They descend into the well by a fixed ladder.

With a deeper occurrence of groundwater, their control is carried out using wells. The design of the facilities should ensure the protection of groundwater from accidental contamination, the possibility of drainage and pumping, as well as the convenience of taking water samples. The volume of indicators to be determined and the frequency of sampling are substantiated in the landfill monitoring project.

In selected samples, the content of ammonia, nitrites, nitrates, bicarbonates, calcium, chlorides, iron, sulfates, lithium, COD, BOD, organic carbon, pH, magnesium, cadmium, chromium, cyanides, lead, mercury, arsenic, copper, barium is usually determined. , dry residue, etc.

If in the samples taken downstream a significant increase in the concentrations of analytes compared to the control is established, it is necessary, in agreement with the regulatory authorities, to expand the scope of the determined indicators, and in cases where the content of the analytes exceeds the MPC, it is necessary to take measures to limit the intake of pollutants into groundwater up to MPC level.

Above the polygon at surface water sources and below the polygon at drainage ditches, surface water sampling sites are also designed. The selected samples are examined for helminthological, bacteriological and sanitary-chemical parameters.

If in water samples taken downstream of surface water a significant increase in the concentrations of the determined indicators is established in comparison with the control, it is necessary, in agreement with the regulatory authorities, to expand the scope of the determined indicators, and in cases where the content of the determined substances exceeds the MPC, it is necessary to take measures to prevent releases of pollutants into surface water bodies up to the MPC level. Roads for vehicles are designed to control facilities for ground and surface waters and the possibility of drainage or pumping out of water before sampling is provided.

The estimate for the construction of the landfill provides for the cost of installing samplers for taking water samples used in the water supply and sewerage system.

The monitoring system should include constant monitoring of the state of the air environment. To this end, it is necessary to quarterly analyze atmospheric air samples above the exhausted areas of the landfill and at the border of the sanitary protection zone for the content of compounds that characterize the process of biochemical decomposition of MSW and pose a great danger.

The volume of indicators to be determined and the frequency of sampling are substantiated in the landfill monitoring project and agreed with the authorized bodies. Usually, when analyzing samples of atmospheric air, the content of methane, hydrogen sulfide, ammonia, carbon monoxide, benzene, trichloromethane, carbon tetrachloride, chlorobenzene is determined.

In the case of establishing air pollution above the MPC at the border of the sanitary protection zone and above the MPCr.z. appropriate measures must be taken at the workplace of the landfill, taking into account the nature and level of contamination.

The monitoring system should include constant monitoring of the state of the soil in the zone of possible influence of the landfill. For this purpose, the quality of soil and plants is controlled for the content of exogenous chemicals (ECS), which should not exceed the MPC in the soil and, accordingly, not exceed the residual amounts of harmful ECS in the vegetable marketable mass above the permissible limits. The volume of ECM to be determined and the frequency of control are determined in the landfill monitoring project and agreed with specially authorized environmental protection authorities.

7. Landfill gas collection and treatment

7.1. General information on landfill gas, gas condensate, quantity and quality.

Landfill gas is formed due to the fermentation of organic components in the waste in the body of the landfill during biochemical decomposition processes. In addition to the gaseous decomposition products, the gaseous components of the sediments (eg greenhouse gases) and water vapor (in the saturated state) are also formed.

The resulting gases and vapors form a wet gas mixture of variable composition. The main components of this mixture are methane CH, carbon dioxide CO.

Due to its main components, as well as the presence of other hazardous components, landfill gas emissions can have a harmful effect on the environment in the form of:

Dangers of explosion, burning, smoke;

Interference with landfill reclamation;

Distribution of the appropriate smell;

Emissions of toxic or hazardous to health constituents;

Harmful impact on the climate.

Based on this, the gases must be collected and disposed of (processed).

The occurrence of landfill gas occurs in five phases, the reduction of formation - in four (Table 1).

Table 1

Phases of landfill gas formation

Phase	Name	Process
I	Oxidation (aerobic phase)	Education landfill gas
II	acid fermentation
III	Unstable fermentation methane
IV	stable methane phase
V	methanogenic long term
VI	Entry phase air	Decrease education
VII	Phase of oxidation methane
VIII	Carbon dioxide phase
IX	Air phase

Due to the duration of the waste disposal process, there is a local overlap of various phases. The presence and condition of the surface coating system also influences the formation of gas, since biochemical decomposition of organic substances and the formation of gas occurs with the cost of water; the body of MSW with a reduced flow of water slowly dries out.

Prior to the construction of a landfill gas collection and treatment system, thorough and comprehensive studies should be carried out, including a complete analysis of the composition of landfill gas.

7.2. Studies to determine the composition of landfill gas.

To assess the probable environmental pollution and danger in the course of landfill gas emission, as well as its possible energy potential, as a rule, comprehensive gas engineering studies are carried out. The results obtained are the basis for the development or selection of systems for the collection and processing of landfill gas.

Gas technical measurements consisting of FID (flame ionization) and measurements at the soil surface can be used as primary studies. Taking into account the indicators obtained during measurements, a multi-month gas extraction experiment is being planned, during which gas is actively pumped out at the demonstration site of the landfill.

Since gas engineering studies show the instantaneous state of gas origin, they are supplemented by a developed quantitative forecast for gas production (to determine the time dependence of the gas generation schedule). If the tests carried out on pumping gas suggest the origin of the gas in the pile of the landfill and a significant emission potential, it is necessary to plan and build an active system for collecting landfill gas and processing it.

7.3. Expected gas output.

With a sufficient number (i.e. over the entire surface) of gas wells, the actual volumes of gas pumped out per unit of time depend largely on the structure and degree of coverage of the landfill, associated with these conditions of humidity in the body and on the system of wells used.

7.4. Component composition of landfill gas.

The component composition of the gas is established on the basis of the results of the study of samples (extracts) of landfill gas. The number of main components for landfills with typical landfill gas generation is within the following limits (Table 2).

table 2

Components of landfill gas

Landfill gas may also contain other components.

7.5. The amount of water condensate and its composition.

The resulting landfill gas enters the system in a state saturated with water vapor, and at a high load of pumping gas from a well (well), it may contain drops of water (aerosol). Due to the cooling of the gas in the pipeline system, water condensate is released from it.

The released condensate flows freely along the foot of the gas pipe to the next low point where condensate is removed from the gas system.

Since the extraction side of the gas system is always under vacuum, the separator must be leak-tight (vacuum-tight).

On the pressure side of the gas system, where the pressure is higher than atmospheric pressure, condensation is unlikely to occur. A small amount of water condensate may form during the temperature cooling of the pipeline during maintenance shutdowns of the connected gas consumers (high temperature flare).

Water condensate released from landfill gas consists (according to the formation mechanisms) of water (the main constituent), steam-distilled components (ammonium), condensable other substances and leachate from the landfill (in the event of breaks during pumping). The calculation of the expected amount of condensate is based on the results of pilot sampling of landfill gas from boreholes.

7.6. Technological scheme for the collection and utilization of landfill gas.

The plant for active removal of landfill gas primarily performs the task of reducing emissions, and after construction - protecting the top cover of the pile of solid waste against damage by rising landfill gas. The installation consists of the indicated side collectors (boreholes, gas wells, gas pipelines, control system), as well as a flare unit and a condensate pipeline system. If the quantity and quality of landfill gas allows its economical use for electricity generation, it is necessary to build a block thermal power plant with the possible use of thermal RES. Landfill gas collection points in connection with the ongoing waste disposal process should be designed in such a way that the process can continue further, and the landfill surface is only later partially subjected to final sealing. This means that the construction of devices for collecting landfill gas should be carried out in stages, corresponding with waste disposal and partial sealing of the solid waste pile. It is possible to choose a device for collecting landfill gas at low or high points, as well as in a mixed way. The advantage of collection at low points is the return flow of condensate into the gas well. This creates a barrier to ongoing drying and thus influence on the formation of landfill gas.

The removal of gas from the landfill should primarily be carried out by pumping from vertical wells (wells), which makes it possible to remove gas from large areas of various sections of the landfill. Due to the subsidence and settling of the landfill body due to compaction and massive reduction in volume during biological decomposition processes, the functional operation of horizontal drainage is at great risk, and such drainage should be used in exceptional cases. Each vertical well is regulated separately by means of a valve and is connected by a pumping pipe to the collecting traverse of the regulating gas station. Gas from the wells enters the collecting gas pipeline, and from it in the form of mixed gas is supplied to the flare unit or to the block TPP.

Prefabricated manifolds are located in closed gas control stations in accordance with industrial safety requirements (primarily frost protection in winter). Pumping and utilization of landfill gas occurs through the pumping station using an integrated high-temperature torch.

Access to the landfill gas collection facility should be provided through the main entrance to the landfill or through internal production routes. The control station, as well as the gas pumping unit and the flare unit, must be located in an area that is not subject to shrinkage in order to ensure reliable operation. They are entered through a locked door. The pumping station consists of machine and switching rooms. It is preferable to provide access to the switching room through a single door, to the machine room through a double door. The torch can be integrated in the pumping building or installed freely. The arrangement of the individual parts of the installation must take into account the necessary fire safety rules and distances.

7.7. General safety provisions in the landfill gas collection and disposal system.

In a simplified form, landfill gas (biogas) can be considered as a binary gas mixture with methane and carbon dioxide components. At a certain concentration of a mixture of methane and oxygen, an explosive mixture occurs. The explosive range of a gas-air mixture of pure methane with atmospheric air is in the range from 5 to 15% by volume.

Due to inert gases, which are carbon dioxide and nitrogen, this range is significantly limited. With an increase in the amount of CO2 or N 2, the explosive range narrows from the lower limit until the moment when the amount of air reaches 58% and the upper and lower explosive limits coincide.

In the course of measures for pumping gas in gas pipelines, there is a danger of drawing in atmospheric air from the pumping side. The drawing in of air in the area of ​​low pressure can occur in the course of, for example, depressurization of the gas pipeline (the formation of a leak in the gas pipeline).

On the pressure side of the fan, landfill gas may leak into the atmosphere due to depressurization of pipelines. In the event of ignition of an explosive mixture of methane and air in a closed system, depending on the composition of the mixture, significant explosive pressure may occur, therefore, technical systems for measuring, removing and harmlessly disposing of landfill gas must be equipped, operated and supervised to comply with the technical requirements security. In addition to the emergency stop function, activated by the set critical values ​​of CO2 and CH4, as well as the temperature rise in the flame damper in front of the unit, not only the emergency shutdown of parts of the system is carried out, but also the corresponding notification. This function is also activated when the gas concentration in the room increases.

8 . Landfill closure

The closure of the landfill for receiving solid waste is carried out after filling it to the design level. The last layer of waste before closing the landfill is covered with a layer of soil, taking into account further reclamation. When planning the insulating layer, it is necessary to provide a slope to the edges of the landfill.

The design of the insulating layer of the landfill is determined by the task for its reclamation. The strengthening of the external slopes of the landfill should be carried out from the beginning of the operation of the landfill as the height of the storage increases. The material for covering the external slopes of the landfill is the vegetable soil previously removed during its construction.

To protect against weathering or washout of soil from the slopes of the landfill, it is necessary to green them immediately after laying the insulating layer. Protective plantings are planted along the slopes and terraces are arranged. The choice of species of trees and shrubs is determined by local conditions.

In areas subsequently used for open storage of non-food containers, the thickness of the upper insulating layer should be at least 1.5 m. depending on the type of crops grown. The top layer of waste before covering it with insulation must be carefully compacted to a density of at least 750 kg/cu. m.

According to EU rules, after filling individual sections or the entire landfill and stabilization of the settlement of MSW, it is necessary to apply a surface sealing system.

The surface sealing system according to the existing EU regulations must contain the following components (from top to bottom):

Artificial impermeable layer (polymer sheet);

Impenetrable mineral layer;

Drainage layer more than 0.5 m thick;

Top surface coating with a thickness of more than 1 m.

To avoid loss of function of the drainage layer, it is necessary to lay an inert material (sand) or filter-resistant geotextile between the drainage layer and the upper surface coating.