Abstract: Methods for the disposal of industrial and domestic waste. Sharing?! Technologies for processing industrial and domestic waste Methods for processing industrial and domestic waste briefly

AT recent times in many countries there is a growing interest in waste as a valuable raw material, and this applies not only to places where raw materials are limited. Reuse of materials in the process industrial production, as a rule, requires less energy, hence the tangible economic benefits of recycling, so an increasing share of the garbage collected in the world is recycled. Will we also join the advanced countries in terms of waste management?

Somewhere in Sweden, for example, it was possible to bring this share to a record 95%. Of course, one should not think that all waste there is recycled, after all, many materials can be used in commercial production only once, and this figure includes all possible types of waste processing, including incineration and pyrolysis decomposition. But some materials that are very common in everyday life can circulate in production almost forever. Take, for example, newspapers. News becomes obsolete faster than the font of the column is typed, there is no need to hem it, tea, not Pravda, and the use of old newspapers for packaging, kindling and ersatz toilet paper is not developed abroad. So the scheme: “bought-read-handed over” works flawlessly there. The development of electronic media is steadily reducing the circulation of their paper versions, which makes it possible to print new newspapers on recycled materials alone. The circulation of newsprint, like packaging board, is important not only because of the preservation of living trees, but also because the production of paper from wood is a labor-intensive and relatively environmentally dirty process.

Another "eternal" material is plastics belonging to the group of thermoplastics. Their fundamental property is that they can be repeatedly melted to give the desired shape, while they do not lose their properties. Such, for example, is polyethylene terephthalate, known to everyone from PET bottles. Producing a new polymer from raw materials is much more expensive than blowing new ones out of old bottles. Moreover, this material is the most inert among household plastics, not exposed to UV rays, like polyethylene, and blowing equipment is widely distributed and, as they say, is on site.

Another widely used material for the production of bottles and other utensils is glass. This is really an eternal product without any quotes, although it sinks in water, it does not burn in fire. To obtain it, in addition to energy, selective river sand is required, a resource in a certain sense is limited, since road and housing construction is constantly growing and the use of cullet as a recyclable material is becoming more profitable. existed in Soviet time of course, the glassware circulation system was not recycling, but it allowed enterprises pouring food liquids big country reduce costs by using universal packaging.

And finally, metals. The tinplate and aluminum used to make cans can be remelted countless times, and their reuse brings tangible benefits to the economy due to the fact that it takes an enormous amount of energy to first extract iron and aluminum from ore. But the use of recyclable materials not only reduces production costs, it also reduces the volume of garbage removed from households to landfills and, accordingly, reduces the size of the areas allocated for these landfills.

These four types of materials, according to various estimates, account for up to 40% of the contents of an average bag of solid waste. Note, however, that most of them are nothing more than packaging of food or industrial goods purchased in supermarkets, easy to sort, not requiring pre-treatment, such as washing, disassembling, etc. And, to For example, it will not be so easy to return a valuable steel pan with plastic handles to industrial circulation. But statistics are created by volumes, so they are the main focus.

Any recycling begins with collection, and it will be better and more complete, the more a trash can looks like a shopping cart. That's right, before we all got used to packing solid waste in special bags, it's time to return to forgotten buckets. Go out with such a bucket into the yard, and newspapers out of it in one container, plastic bottles in another, glass in the third, cans in the fourth. Only non-recyclable waste is all in one bag and, accordingly, in the fifth container, and then return the bucket home. Nothing to say, an occupation worthy of pensioners and schoolchildren, hastily throwing a bag on the way to work will no longer work, and whatever one may say, additional space in the apartment for “recyclable” waste will be required.

The conscience of the townspeople alone may not be enough for this, and there is nothing to motivate them financially. With an average price of waste paper 2 rubles. for 1 kg, the collection points that were available in the recent past "have died for a long time", and 50 kopecks. for 1 kg of cullet or 25 kopecks. for an aluminum can, all the more, they will not inspire anyone. But reducing the cost of MSW removal through municipal support for residents participating in the separate collection program can be a good incentive. It is also important to simplify the collection of sorted waste as much as possible, for example, to collect all recyclable waste in one container, then there will be no need for a “palisade” of multi-colored tanks in the yards, but only two types; hurried working people will be able to recycle everything in one package, as before. Abroad, when serving the private sector, they do just that: they put two 120-liter containers at each house: one for recyclables, the other for non-recyclable solid waste. In houses with garbage chutes, they can be taken away for secondary resources, and “smelling” bags can be taken outside by hand, it will be even more hygienic.

Well, the important point is the responsibility for your garbage. There will be no order, even if all the vandals suddenly turn into respectable citizens, where residents of various HOAs and management companies bring garbage to a common municipal solid waste collection site, and even nearby shops throw their waste. General - it is actually a draw, we have already gone through this. The collected secondary raw materials "mixed" can then be sorted on special lines with partial use of manual labor. Such work will not be fundamentally different from any industrial conveyor. It is quite another to pull out metals from MSW mixed with organic waste. You won't even need a special garbage truck to take out garbage from the yards, one truck will pick up recyclables in the first half of the day, and the rest of the non-recyclable garbage in the second. Today, many contractors already make two trips a day to keep the sites clean.

Another option is the use of garbage trucks with a separate body and two press chambers, which will allow picking up both types of waste in one trip. The disadvantage of these garbage trucks is that the body is not divided in half and the smaller compartment works only with small containers, and if euro containers with a volume of 1.1 m 3 are used for collection, such machines will not be suitable for them. In this case, the so-called "overloaded" garbage trucks will help out the public utilities workers. They are built on medium-tonnage chassis and offer bodies from 5 to 8 m 3 . Their receiving chamber is designed in such a way that they can lift Euro-containers of all standard sizes and can be unloaded into a rear-loading garbage truck on a heavy road chassis. A large garbage truck does not participate in the collection of solid waste, it remains at the base and does not burn fuel in vain, maneuvering in cramped yards or standing idle in traffic jams. Instead, all the “dirty” work is done by “little” medium-duty trucks, and after filling up its body, it is sent to the landfill or to the sorting and processing line, depending on the cargo.

ISKUB LLC is the official representative in the Russian Federation and the CIS of one of the world industry leaders - the Italian DULEVO International and supplies special Dulevo 5000 Compatto urban garbage trucks on a self-propelled chassis of its own design. They are also categorized as "overloadable". The body with a volume of 10 m 3 is equipped with pressing equipment with a compaction ratio of 5:1. These machines differ from analogues on automobile chassis primarily due to their compact size and high maneuverability due to the continuously variable hydrostatic transmission and fully steerable wheels with a turning radius of less than 9 m. A significant plus is the low-floor cab - this reduces operator fatigue and makes it easier to maneuver in an urban environment, for example, in yards and on the streets where there are a lot of parked cars. Hydraulic adjustment of the height of the suspension allows you to reload the garbage in any large-capacity garbage truck without the use of auxiliary devices.

As for public places, streets, squares, recreation areas, it is possible to sort waste to the fullest, they are directly formed there, you don’t need to pre-store them like at home, it’s only important to choose the right bin separately for glass bottles and separately for cans from aluminum. Particularly conscious citizens can even be taught to sort separately printed editions by type of paper, and a glass bottle by color. Litter bins and small "Euro-buckets" with sorted waste are unloaded manually into special garbage trucks "Kerbsiders". Their body is divided into several sections without pressing equipment, compartments are loaded using buckets placed on the side of the machine for models on large road chassis. For medium-tonnage vehicles, the compartments are filled through the side doors. The most outlandish models of "kerbsiders" look like cabinets with wheels, removable compartments-drawers on both sides of the machine are filled manually and unloaded using a forklift or simply removed and sent to another mode of transport for recycling.

Alas, in order to increase the degree of recycling, the means of collection must be like the means of delivery of goods, and the handling of recyclables must be appropriate. Mechanize the selective collection of MSW in in public places allow large containers, modernized to collect one type of waste, and "secret" or double-bottom bins, in which, like icebergs, a small part rises above the surface of the sidewalk, and the main bin is hidden underground. Garbage trucks equipped with a special crane-manipulator, and ground and underground containers adapted to work with them can completely free workers from manual labor during selective collection. Unlike in-depth polypropylene "stockings", there are no slinging works here. On the upper part of the container or underground bin there are two loops: one for lifting the bunker, the second for opening the bottom flaps for unloading. On the boom of the manipulator there is a corresponding hitch with two clamps for loops. He brought the arrow to the container, hooked it, lifted it, put it over the receiving chamber, unloaded it, put it in place. All operations are carried out, as the “cinema” chief said, without noise and dust, however, glass bottles, of course, with noise.

However, there are underground urns, inside of which are hidden ordinary Euro-containers with a volume of 1.1 m 3. When unloading, the "false sidewalk" with the urn is raised, and the container is rolled out manually and unloaded into a conventional garbage truck. Not only garbage trucks can be used for separate collection of waste, but also trucks equipped with a “multi-lift” system due to special interchangeable bodies. First of all, it is a press compactor. With a little modification, it will be possible to unload any European-type garbage containers from 0.12 to 1.1 m 3 into the chamber. Where is it in demand? Lots of places: exhibitions, markets, shopping malls, territories of various organizations. Waste there can be selectively collected in Euro-containers, then their workers, as they are filled, will unload them into a press compactor standing aside. Tin cans in the fresh air, as you know, do not deteriorate, when the hopper presses recyclable materials to failure, you can order the export. Thus, organizations will not only minimize their waste management costs, but will also be able to receive additional income from the sale of recyclables.

An important difference between the conditional package of a European city dweller and our home-grown one is the absence of organic waste in it. And it's not about the development of fast food there. It’s just that abroad, all “organic matter” safely goes into the sewer network through a chopper installed in the drain of the sink. With us, this is still exotic, and more items are sent to the sewer for which it is not intended at all. Meanwhile, the release of garbage containers from organic residues is not only a reduction in the volume of exported solid waste, but also a way to deal with a specific garbage "flavor". In addition, organic waste, then collected in the sludge, can be composted to produce methane, for example, which is also, in fact, waste processing. And it is easier and cheaper to organize it than to collect organics selectively through the system of solid waste removal.

ZAO Kominvest-AKMT this year, setting a trend for the market, it presented one of the most discussed novelties of its own production - a heavy-duty rear-loading garbage truck T1S-10 on an Iveco chassis with FARID attachments, which has no analogues on the Russian market. Garbage truck is designed for mechanized and manual collection of municipal solid waste.

The advantages of the model are a frame body made of square pipes, inside the tubular frame a spherical body is built-in, made of solid sheets of high-quality steel resistant to deformation, and a loading hopper floor made of wear-resistant Hardox steel 8 mm thick. A body with a rounded shape with a capacity of 10 m 3 allows you to evenly distribute the pressing force around the entire perimeter, excluding deformation processes. The floor material of the body is made of steel with a hardness of 140 HB and a thickness of 4 mm.

The design of the receiving hopper with a capacity of 1.3 m 3 with a floor made of 450 Hardox steel 8 mm thick is supplemented with a folding side to facilitate manual loading of solid waste. Packing plate cylinders are located outside the feed hopper and are protected by hinged panels to keep small debris out of the rods and increase structural integrity. Debris compaction ratio 6:1. Two drain cocks exclude spillage of the filtrate on the container platforms. Unloading of waste is carried out by a pushing plate. In the process of unloading, the plate in its extreme extended position in the lower part extends 100–150 mm beyond the body for easy cleaning of the body.

The garbage truck is equipped with a universal tilter that allows you to work with all types of euro containers with a volume of 120 to 1100 liters. Thanks to electronic and manual control of compaction cycles, the operation of the garbage truck is as comfortable and efficient as possible. At the request of the customer, the model can be equipped with GPS navigation, a rear-view camera and a weighing system for loaded waste, for example, a mobile device with the function of printing checks based on the weight of loaded waste. A high performance hydraulic system with a working pressure of 210 bar ensures fast operation of the units and fast unloading / unloading. The T1S-10 rear-loading garbage truck on an Iveco chassis with FARID attachments has embodied all the innovative ideas that combine modern and functional design, reliability and excellent performance.

Of great importance for the environment are hazardous waste, which is abundant in our everyday life. Household chemicals, varnishes, paints, gasolines, oils, acids and alkalis, batteries, mercury-containing lamps and thermometers - today, when all this without a twinge of conscience is sent straight to garbage cans by the vast majority of our citizens, the selective collection of hazardous waste is becoming real way preserve the health of nature, and therefore of man.

However, even with the exception of hazardous organic and recyclable waste, the weighted average package with MSW will decrease by half at best. How to deal with the remaining, let's call it "unclaimed" garbage? There are three main methods for its disposal. Storage (deposit) at the landfill, incineration and pyrolysis decomposition. The latter option is becoming more and more popular in the West. Its essence is that the waste is destroyed under the action of high temperature in an oxygen-free environment. The method makes it possible to obtain energy, collect volatile hydrocarbons, and remove metals from the resulting “porridge” from the waste. Most of the hazardous substances remain in the "melt", the volume of waste to be disposed of is reduced. It's time for us to be more actively interested in pyrolysis, especially in large cities, where a lot of solid waste is formed, and the ecological situation is tense. The efficiency of pyrolysis is clearly demonstrated by the transformation of car tires into mineral oil and carbon black (soot). You can’t make new tires out of this, but you can find application in production.

Incineration is the oldest way of getting rid of waste, which arose immediately after the development of fire by man. This method allows you to minimize the volume of solid waste, depending on the material, up to 10 times. A large amount of heat is released, from which electricity can be obtained; in terms of heat production, MSW is comparable to peat or brown coal. It is convenient to extract valuable raw materials from ash, and especially enterprising citizens strive to attach the ash itself with profit, so to speak, to establish waste-free production. It should be noted that it is difficult to frighten our people with anything, they themselves are ready to live in houses built of bricks with ash from incinerators. At the very least, bonfires were banned in the cities, but look at any gardening cooperative, what kind of training grounds are arranged right at the main gate. Not only do they burn trimmings and tops - they do not hesitate to throw batteries, and the remains of pesticides, and even mercury thermometers into the fire. What can you do, the clothes on these people are different, but their mentality is still Soviet. Abroad, not a single cut branch is lost: either it goes to the production of fuel pellets, or to generate electricity at thermal power plants.

In terms of environmental impact, wood is a clean fuel, only natural gas is cleaner. In our country, cut-down city poplars are thrown into ravines as whole trees, to say nothing about branches! In the process of constant housing repairs, so many wooden structures are released: window frames, doors, partitions, and all this is dumped to rot at the landfill. Under socialism, we lived as if we had discovered the secret of absolute energy, because the state provided energy resources at a gratuitous price, and now we are reaping the benefits in the form of a complete lack of motivation among people, both to protect nature and save energy. And it would be nice to attach modules for burning all kinds of wood waste in every city at the CHP.

But division by division, and at least a third of our population lives in settlements where there is no demand even for an aluminum can. And in big cities, garbage will always accumulate, and it will be unrealistic to find a use for it. The same technological progress contributes to this. How, for example, to recycle old TVs or monitors? Meanwhile, many household waste materials are inert, practically do not interact with the environment, and when they are deposited at landfills, they are only mechanical pollutants. But they, in fact, are both roads and residential buildings - all this is the land taken away from green plants. But in the case of a properly organized landfill, after its reclamation, grass and trees return to their place.

But the way to modernize the deposition of garbage at the landfill, allowing to reduce its volume and the need for land allocation, will be the preliminary crushing of solid waste. The garbage passed through crushing plants will be easier to compact into the ground, and crushed hard grade polymers can even be used in the household for backfilling pits, preparing the roadway, etc.

The main thing is that more and more people share the idea of ​​separate collection and processing of solid waste.

For improvement environmental situation modern technologies waste disposal in places of waste storage, it is proposed to use shredders and compactors for solid waste. The use of a specialized SDW shredder will allow you to get rid of bulky waste (furniture, trees, tires, construction waste, plastic, etc.). Shredded waste can be used for filling the landfill, preparing access roads.

The seal will reduce the amount of airborne debris and achieve high density waste, reduce voids, reduce the risk of fires; save the soil used to cover the landfill due to the leveled surface; reduce the risk of damage to the chassis Vehicle who bring garbage; increase the life of the landfill by 25–40 years: a larger amount of waste is placed on a smaller area due to an increase in their density.

ISP Group (CJSC Infrastructural Project) offers TANA compactors for compacting waste at landfills (landfills) of MSW. The model range includes models: Е260-26 t, Е320-32 t, Е380-38 t, Е450-45 t, Е520-52 t. Machines provide compaction of waste 950–1200 kg/m 3 , compaction capacity – 80 t/h or 400 m 3 /h The crushing force of the rollers is from 127 kN to 255 kN, the pressure on the ground in motion during the first pass is from 49–68 kg/cm, during the third pass – from 108–152 kg/cm. For comparison: crawler tractors can generate pressure from 470 to 590 kg/m 3 and the TANA four-wheel packer from 700 to 900 kg/m 3 . A roller with solid drums compacts with a force of 950 to 1200 kg/m 3 .

This technique is already successfully used in Russia. It is able to solve the problems of old landfills (example: Arkhangelsk - a landfill of the 1970s. After the purchase of a compactor in 2008, the operation was extended, the landfill is practically within the city, fires have stopped, the issue of urgent construction of a new landfill has been removed). This equipment is purchased to equip new landfills under construction in many large cities of Russia and to extend the life of old landfills and solid waste landfills.

Waste types

The amount of household waste in the world per person is increasing by about 1-4%, and by weight - by 0.2-0.4% per year and currently is (kg / year): in comfortable buildings - 160- 190, in disadvantaged buildings -600-700. The problem of these wastes is currently very acute in many countries of the world. In particular, about 150 million tons of waste is generated annually in US cities.

About 80 billion tons of waste have been accumulated in our country, and their mass is increasing every year. By the beginning of 1997, more than 1.4 billion tons of toxic waste alone had accumulated at enterprises in various industries. In 1995-1997 the annual generation of toxic waste has reached approximately 90 million tons, including hazard class I - about 0.16 million tons, class II - 2.2 million tons, class III - 78.7 million tons. In general, in Russia, the amount of hazardous: waste is about 10% of the total mass of municipal solid waste (MSW).

The largest part of the hundreds of millions of tons industrial waste is formed in the coal industry, enterprises of ferrous and non-ferrous metallurgy, thermal power plants, building materials industry.

Production and consumption waste- these are the remains of raw materials, materials, semi-finished products, other products or products formed in the process of production and consumption, as well as products that have lost their consumer properties. Wherein hazardous waste must be neutralized, and those not in use are considered garbage. Waste can be very different (Scheme 1).

Scheme 1. Main types of waste(according to V.A. Vronsky)

The main methods of disposal of household and industrial waste There are many ways to dispose of waste,

Let's take a look at the most commonly used ones.

Warehousing

Disposal of waste to a landfill is the cheapest, but at the same time short-sighted way of its disposal. It is short-sighted in the first place because garbage remains garbage. Landfills around cities occupy huge areas. Poisonous substances that end up in landfills penetrate into groundwater, which is often used as a source of drinking water, is blown around by winds, and thus damages the environment. In addition, as a result of decay processes without air access, various gases are formed, which also do not refresh the atmosphere around the landfill. Some decay products can spontaneously ignite, so fires regularly occur in landfills, in which soot, phenol, benzapyrene and other toxic substances are released into the atmosphere.

The volume of landfills in our cities is doubling approximately every 10 years.

Another way of recycling is not just removal to a landfill, but waste disposal with subsequent reclamation.

Approximately 2/3 of all household and industrial waste is stored in landfills. Such storage facilities occupy large areas, are sources of noise, dust and gases,

formed as a result of chemical and anaerobic biological reactions in the thickness.

Before burial, a number of activities are carried out:

Dig a pit

The bottom is lined with silt

An insulating material is placed on a layer of silt

Then alternately follow - a layer of waste and a layer of soil

Carry out compaction of waste

Drainage treatment plant is installed to remove liquid waste Wastewater

Then they fall asleep with a thick layer of soil and plant green spaces.

Many countries with access to the sea carry out sea burial of various materials and substances - dumping, in particular soil excavated during dredging, drill slag, industrial waste, construction debris, solid waste, explosives and chemicals, radioactive waste . The volume of burials amounted to about 10% of the total mass of pollutants entering the World Ocean.

It is not known which of these two methods is better, since, on the one hand, the buried garbage does not produce dust flying around the landfill and does not spoil the landscape so much, and on the other hand, the waste is closer to groundwater. In addition, waste disposal is an expensive process.

2. Incineration

In order to free up the vast areas occupied by landfills, the idea of ​​incinerating waste arose.

The first systematic use of waste stoves was tested in Nottingham, England, in 1874 Incineration has reduced the volume of garbage by 70-90 %, depending on the composition, so it has found its use on both sides of the Atlantic.

The densely populated and most significant cities soon introduced experimental ovens. The heat released from the burning of garbage began to be used to generate electricity, but these projects were not able to justify the costs everywhere. Large expenses for them would be appropriate when there would be no cheap way of burial. Many cities that used these stoves soon abandoned them due to the deterioration of the air composition. But even now, up to 50% of all waste is incinerated in developed countries.

Incineration is not the most profitable option - both in monetary terms and in terms of resource saving.

Non-combustible materials, such as metals and glass, retain their value when recycled, but when incinerated, they only take up space in warehouses and furnaces. Organic waste is better used for composting than ignoring it high humidity trying to burn them. Paper

and plastic, on the other hand, is a valuable fuel. Unsorted waste has a calorific value of about 8400 J/kg, which is half the calorific value of coal. The heat of combustion of paper and plastic is 2 and 4 times higher, respectively. Therefore, it is not practical to burn all the materials together.

The German Greens believe that incinerators only convert one form of pollution into another, but do not eliminate it.

Recently, emphasis has been placed on plasma combustion waste (temperature about 30,000 C). The high energy intensity and complexity of the process predetermine its use for the processing of waste only, the fire disposal of which does not meet environmental requirements.

3. Solid waste composting

Composts- These are organic fertilizers obtained as a result of the decomposition of plant and animal residues by microorganisms. When composting in the organic mass, the content of nutrients(phosphorus, nitrogen) in a form digestible by plants, pathogenic microflora is neutralized, the amount of cellulose and pectin substances decreases; fertilizers become free-flowing, which facilitates their introduction into the soil. Composts are often used instead of scarce organic fertilizers (peat, manure).

When composting in special (compost) installations, a temperature of up to 70 ° C is created, at which microbes and weed seeds die. Composting is considered quite a rational way to eliminate certain waste almost no harmful effect on the environment. However, when processing waste containing metals, the latter can accumulate in the compost in large quantities.

4. Burial of toxic industrial waste

recyclable industrial waste should be carried out within special landfills that ensure their isolation and environmental safety for such a period until they become harmless to humans or economically viable technologies for their processing and subsequent use are developed.

Underground industrial waste storage facilities include those located in geological formations remote from the earth's surface, providing long-term isolation of waste from the biosphere.

Underground storage facilities are environmental structures and are designed for centralized collection and disposal of waste (including toxic waste) from industrial enterprises, research organizations and institutions. The placement of industrial waste in storage facilities can serve two purposes - their subsequent use (storage) and eternal burial.

In the conditions of modern growth of industry and the population of cities, the problem of waste disposal is becoming more and more urgent. Garbage dumps are limited and in short supply. In addition, they provide Negative influence on the environment, which is already suffering from gas pollution and emissions from large enterprises. Therefore, it is required to build waste processing plants away from settlements, as well as the use of modern methods of obtaining recyclable materials and recycling.

Natural waste recycling

In the last century, recycling of household waste by composting it was popular. To do this, they dug out pits and dumped waste of organic origin there and sprinkled it with earth. During the processes of decay and decomposition, organic fertilizers were formed over time. Not so long ago, this method was improved: they began to produce special heated hermetic installations. When heated, organic waste decomposes faster, resulting in the formation of biogas (methane), which began to be used for the production of biofuels.

Large firms began to manufacture mobile stations that are able to provide processing to private farms and small villages. For large cities, large plants similar in principle of operation could be used, but they are unprofitable, since it takes a lot of time to decompose, and the resulting fertilizers need to be put somewhere. In addition, such installations are not able to process other types of waste that will accumulate. These include construction waste, plastic and polyethylene products, etc. The solution would be the construction of specialized factories, but this is not economically viable.

Waste recycling by thermal action

Thermal processing is the burning of municipal solid waste in order to reduce the volume of organic matter, neutralization and subsequent disposal or disposal. At the same time, as a result of combustion, the initial volumes are reduced several times, all bacteria are destroyed, and the released energy can be used to heat water in heating systems or generate electricity. Typically, such plants are located near large landfills, where organized garbage removal from all over the city and there is an opportunity to bury waste from processing at landfills.

Combustion can be direct or pyrolysis. With direct combustion, only thermal energy is obtained, and during pyrolysis, two types of fuel are formed: gas and liquid. Both methods have a significant drawback - harmful substances are released into the atmosphere during combustion, which causes significant harm to the environment. Even the installation of filters to retain solid volatile substances does not fundamentally change the situation for the better.

Plasma recycling of waste

Plasma processing is currently the most modern way garbage destruction. The essence of the process is as follows:

• The garbage is crushed, pressed and, if necessary, dried to obtain a granular structure;
• The granules are placed in a special reactor, where, with the help of a plasma jet, required amount energy, and they pass into a gaseous state.

To prevent combustion, an oxidizer is launched into the chamber. The result is a gas similar to natural gas, but with a lower energy content. It is collected in large sealed containers for further processing and use as fuel for diesel generators, boilers, and gas turbines.

This method of waste disposal has long been used in the United States and Canada. They have learned not only to recycle waste, but also to effectively use the by-product - gas as fuel. All conditions have already been created for this in the West, but in the post-Soviet space new technology not widely used due to expensive equipment and high requirements for the qualifications of service personnel.

Conclusion

New waste recycling technologies require financial investments and interest at the state level. But while there are factories with outdated equipment, and they cope with volumes, build modern factory no one will, or until an ecological catastrophe comes.

The modern world does not stand still. Every year, production volumes increase, population growth and urban expansion continue. At the same time, the problem of waste disposal has ripened. On the ground, special landfills for waste products are present in limited quantities. At the same time, the volumes entering them exceed their capacity, so the garbage mountains increase every day. Untreated heaps of waste negatively affect the ecological state of the planet. That is why there was a need to create high-quality waste processing plants. At these facilities, it is necessary to apply only modern methods of waste processing and disposal. It is worth noting that the garbage generated by mankind belongs to various hazard groups. In order for waste recycling to be effective, for each individual type it is necessary to choose its own disposal method. But first they need to be sorted.

Waste household

This number includes the remains of products associated with the life of people. It can be plastic, paper, food and other similar waste that was thrown out of institutions and homes of the population. The rubbish that we used to get rid of is found at every step. Many garbage is assigned the fifth and fourth degree of danger.

Recycling of household waste from plastic should not be done without mechanical action, i.e. grinding. Further, they are necessarily treated with chemical solutions. Often, after such a procedure, new polymeric substances are made, which are used again to create new products. Household waste such as paper or food waste can be composted and then putrefied. Subsequently, the resulting composition is suitable for use in agricultural business.

Biological decay

Biological species in nature are humans and animals. These two groups also generate a large amount of waste. A lot of this rubbish comes from veterinary clinics, sanitation organizations, catering establishments and similar businesses. Processing of biological waste is reduced to their incineration. Substances of liquid consistency are transported on special vehicles. Incineration is also used for organic waste.

Industrial waste

This type of waste is generated as a result of the functioning of production and technological activities. This includes all construction garbage. It appears in the process of installation, facing, finishing and other works. For example, this category of waste includes paint and varnish residues, heat-insulating substances, wood and other industrial “trash”. Processing of industrial waste is often incinerated. Wooden remains are suitable for obtaining a certain amount of energy.

radioactive waste

Such wastes include solutions and gases that are not suitable for use. First of all, these are biological materials and objects containing radioactive components in large quantities (above the permissible norm). The degree of danger depends on the level of radiation in such waste. Such garbage is disposed of by burial, some is simply burned. A similar method of processing applies to the next group of residues of activity.

medical waste

This list contains all substances that are produced by medical institutions. Approximately 80% of waste is ordinary household waste. He is harmless. But the remaining 20% ​​are capable of causing damage to health in one way or another. In Russia, the disposal and processing of radioactive and medical waste has many prohibitions and conventions. Also, the country carefully spelled out the necessary conditions for handling this group of garbage, methods for their burial or incineration. Special repositories for liquid and solid radioactive components were created. If it is necessary to get rid of medical waste, it is put in special bags and set on fire. But this method, unfortunately, is also unsafe, especially if the drugs belong to the first or second hazard group.

Division into classes

All waste is divided depending on its state of aggregation. So, they are solid, liquid or gaseous. In addition, all garbage is classified according to the degree of danger. There are four classes in total. Garbage belonging to the first degree of danger poses the strongest threat to the planet and living organisms, including humans. These wastes can ruin ecological system which will lead to disaster. These include the following substances: mercury, polonium, lead salts, plutonium, etc.

The second class includes residues that can cause an ecological failure that will not be able to recover for a long period (about 30 years). These are chlorine, various phosphates, arsenic, selenium and other substances. The third hazard group includes those wastes, after the impact of which the system will be able to recover in ten years. But only if the garbage no longer affects the infected object. Among them, chromium, zinc, ethyl alcohol and so on are distinguished.

Low-hazard waste - sulfates, chlorides and simazine - is assigned the fourth class. But this does not mean that they practically do not affect humans and the ecosystem. If the source is removed, the organism or nature will be able to recover only after three years. There is fifth grade trash. This means that the waste is completely safe for the environment.

The Importance of Recycling

There are several reasons why competent recycling is necessary:

1. Getting into the environment, most substances and materials turn into pollutants (it is worth considering that our planet is already suffocating every day from the emissions of cars and factories).
2. Many of the resources from which certain materials are created are exhausted. Their stocks are too limited, so recycling is the way out.
3. In some cases, objects that have fulfilled their purpose turn out to be a source of substances. Moreover, they are cheaper than natural materials.

More about recycling

Recycling is a change in waste materials until they completely disappear or change the structure so that it is not possible to reuse them. But this word can have another meaning. For example, it is often used in a figurative sense.

Today, a large amount of waste is reused for different purposes. All garbage that is disposed of today is divided into two main groups:

1. Solid household waste (glass, paper, plastic, food waste).
2. Industrial waste (biological, medical, radioactive, construction waste, as well as waste from the transport complex).

Disposal can be carried out in one of several ways, which are also divided into groups. For example, the main methods include heat treatment, composting, which is natural method decomposition, and waste disposal at special landfills. Some of these recycling methods allow you to get secondary raw materials.

Recycled materials

Usually, all the waste that remains after human production and activities is called "recyclable". But this view is not entirely correct. The fact is that not all waste should be recycled or sent to other needs. There is also a group of waste that is reused only as an energy source (after special treatment), therefore it is also not classified as a secondary raw material. Those substances that, after processing, give out energy, are called "secondary energy raw materials."

This group includes only those materials that, after a certain impact, can become suitable in national economy. A good example is a canned food can. It can no longer be used to store food, but after being melted down, it is used to make a new food container or other metal objects. It becomes obvious: secondary raw materials are items that, after being used for their intended purpose, are resources that will be useful for further use. To get a new product or raw material, waste processing is necessary. Today, several methods are used for this, which are described below.

Natural processing

Back in the 20th century, in most cases, the processing of household waste was carried out by composting. Garbage, in particular organic, was dumped into specially dug pits and sprinkled with earth. Over time, the waste decomposed, rotted and was used as fertilizer in agriculture. But relatively recently, this method has been slightly modified. Scientists have developed hermetic installations for heating composted waste. Organic residues in this case begin to decompose faster, which results in the formation of methane, which is biogas. It was he who began to be used to create biofuels.

Specialized companies have appeared that build mobile stations for waste processing. They are used in small villages or on a farm. It has been estimated that such stations large size, intended for cities, it is unprofitable to maintain. It takes a lot of time to get a decomposing product, and the resulting fertilizers still remain unused, and they also need to be disposed of somehow. In addition, there are other wastes that have nowhere to go, so they will accumulate. For example, it is plastic, construction residues, polyethylene and so on. And it is economically unprofitable for the authorities to create a specialized plant where the processing of municipal solid waste would be carried out.

Thermal disposal

Thermal processing refers to the burning of solid household waste. The process is used to reduce the amount of organic matter and render it harmless. Further, the resulting residues are disposed of or disposed of. After burning, the garbage is significantly reduced in volume, all bacteria are exterminated, and the resulting energy is able to generate electricity or heat water for the heating system. Such plants are usually arranged near large city dumps so that the processing of solid waste takes place on a conveyor. There are also nearby landfills intended for the disposal of processed residues.

It can be noted that waste incineration is divided into direct and pyrolysis. With the first method, only thermal energy can be obtained. At the same time, pyrolysis combustion makes it possible to produce liquid and gaseous fuels. But regardless of the method of thermal disposal, harmful substances are released into the atmosphere during combustion. It harms our ecology. Some people install filters. Their purpose is to retain solid volatile substances. But as practice shows, even they are not able to stop pollution.

If we talk about the technology for processing medical waste, several special furnaces have already been installed in Russia. They are equipped with gas cleaning devices. In addition, microwave, steam-thermal treatment and autoclaving have appeared in the country. These are all alternative methods of incinerating medical and other suitable waste. Residues containing mercury are processed by special thermochemical or hydrometallurgical methods.

Plasma Utilization

This method for this moment is the most modern way of recycling. Its action takes place in two stages:

1. Waste is crushed and compressed under pressure. If necessary, the garbage is dried to achieve a granular structure.
2. The resulting substances are sent to the reactor. There, the plasma flow transfers so much energy to them that they acquire a gaseous state.

To avoid ignition is obtained with the help of a special oxidizing agent. The resulting gas is similar in composition to ordinary natural gas, but it contains less energy. The finished product is sealed in containers and sent for later use. Such gas is suitable for turbines, boilers, diesel generators.

Similar processing of production waste and household waste has been used for some time in Canada and the United States. In these countries, the remains of human life are effectively disposed of, and the final product is used for good as fuel. In the West, they are already preparing to introduce this technology on an even larger scale. But since such equipment is quite expensive, it cannot be purchased by the CIS countries.

Is it possible to solve the problem of waste disposal?

Of course, for the processing of solid waste and hazardous waste to be carried out at the highest level, a lot of financial investments are required. Political circles should also be interested in this. But for now, we have to make do with obsolete equipment for recycling. According to the authorities, the existing factories cope with the problem, so there is no need to reconstruct and re-equip them. Only an ecological catastrophe can serve as an impetus for this.

Although the problem is vast, it is still possible to solve or reduce its size. The situation requires an integrated approach on the part of society and the authorities. It is good if everyone thinks about what he personally can do. The simplest thing a person can do is start sorting the garbage that he generates. After all, the one who throws away waste knows where he has plastic, paper, glass or food. If it becomes a habit to sort the remains of life, then such garbage will become easier and faster to process.

A person needs to be regularly reminded of the importance proper disposal waste, sorting and caring attitude to natural resources that he owns. If the authorities do not take measures, conduct motivational campaigns, simple enthusiasm will not be enough. Therefore, the problem of waste disposal will remain in our country at a “primitive” level.

The complex of technical and technological solutions that accompany the processes of waste management from the moment of their formation to the disposal of non-disposable components is the basis for management in the waste management system.

The main methods of waste processing are:

 composting,

 biodegradation,

 incineration.

These methods are especially effective in the processing of MSW.

1. Composting.

Composting is considered a form of processing that targets raw organic waste matter. Composting is a biological method for the disposal of solid waste. Sometimes it is called biothermal method.

The essence of the process is as follows: various, mainly heat-loving microorganisms actively grow and develop in the thickness of the garbage, as a result of which it self-heats up to 60 0 C. At this temperature, pathogenic and pathogenic microorganisms die. The decomposition of solid organic pollutants in household waste continues until a relatively stable material, similar to humus, is obtained.

The mechanism of the main composting reactions is the same as in the decomposition of any organic matter. When composting, more complex compounds decompose and turn into simpler ones.

The cost of composting methods increases with the use of specialized equipment and can reach significant values.

The scheme of work of the waste processing plant is as follows . The completed cycle of MSW neutralization consists of three technological stages:

 reception and preliminary preparation garbage;

 actually biothermal process of neutralization and composting;

 compost processing.

Waste processing must necessarily be combined with the issuance of products that are safe and epidemiologically.

Waste disposal is provided primarily by the high temperature of aerobic fermentation. During the biothermal process, the majority of pathogenic microorganisms die.

However, the compost obtained as a result of biothermal disposal of MSW at waste processing plants should not be used in agriculture and forestry, because contains impurities of heavy metals, which through herbs, berries, vegetables or milk can harm human health.

2. Biodegradation organic waste

It is generally accepted that biological methods for the decomposition of organic pollutants are considered the most environmentally acceptable and cost-effective.

The technology of waste biodegradation process is different. For example: in bioponds - liquid waste, in bioreactors - liquid, pasty, solid, in biofilters - gaseous. There are other modifications of biotechnology.

Significant disadvantages of aerobic technologies, especially in the treatment of concentrated wastewater, are energy costs for aeration and problems associated with the processing and disposal of a large amount of excess sludge generated (up to 1–1.5 kg of microbial biomass for each kilogram of organic matter removed).

It helps to eliminate these shortcomings anaerobic wastewater treatment by methane digestion. At the same time, energy costs for aeration are not required, which plays an important role in the conditions of an energy crisis, the volume of sediment decreases and, in addition, valuable organic fuel, methane, is formed.

The list of substances biodegradable anaerobically includes organic compounds of various classes: alcohols; aldehydes; aliphatic and aromatic acids.

Sequential multistage destruction of molecules of organic substances is possible due to the unique abilities of certain groups of microorganisms to carry out catabolic process – breaking down complex molecules into simple ones and exist due to the energy of destruction of complex molecules, having no access to either oxygen or other energetically preferable electron acceptors (nitrate, sulfate, sulfur, etc.). Microorganisms use carbon from organic substances for this purpose. Consequently, in the process of reductive fission, complex organic molecules are broken down into methane and carbon dioxide.

3. waste incineration

Municipal solid waste is a heterogeneous mixture in which almost all chemical elements are present in the form of various compounds. The most common elements are carbon, which accounts for about 30% (by mass) and hydrogen 4% (by mass), which are part of organic compounds. The calorific value of waste is largely determined by these elements. In industrialized European regions, the calorific value of MSW is 1900–2400 kcal/kg, and in some cases it reaches 3300 kcal/kg, and a further increase in the calorific value of waste is predicted, which will affect the design features of the elements of thermal equipment.

MSW incineration is generally an oxidative process. Therefore, oxidative reactions also prevail in the combustion chamber. The main combustion products of carbon and hydrogen are CO 2 and H 2 O, respectively.

When incinerated, it must be taken into account that MSW contains potentially hazardous elements characterized by high toxicity, high volatility and content, such as various compounds of halogens (fluorine, chlorine, bromine), nitrogen, sulfur, heavy metals (copper, zinc, lead, cadmium , tin, mercury).

There are two main ways of formation of dioxins and furans during the thermal processing of MSW:

 primary formation in the process of MSW incineration at a temperature of 300–600 ºС;

 secondary formation at the stage of cooling of flue gases containing HCl, copper (and iron) compounds and carbon-containing particles at a temperature of 250–450 ºС (reaction of heterogeneous oxychlorination of carbon particles).

The temperature at which dioxins begin to decompose is –700 ºС, the lower temperature limit for the formation of dioxins is –250–350 ºС.

In order to reduce the content of dioxins and furans to the required standards (0.1 ng / m 3) during combustion at the gas cleaning stage, the so-called primary measures must be implemented, in particular, "two second rule" – the geometry of the furnace must ensure the residence time of the gases is not less than 2 seconds. in the furnace zone with a temperature of at least 850 ºС (at an oxygen concentration of at least 6%).

The desire to achieve the highest possible temperatures during combustion and the creation of any additional afterburning zones does not completely solve the problem of reducing the concentration of dioxins in exhaust gases, since it does not take into account the ability of dioxins in new synthesis with a decrease in temperature.

High temperatures lead to an increase in the yield of volatile components and an increase in emissions of hazardous metals.

Theoretically, there are two ways to suppress the formation of dioxins:

 binding of MSW formed during incineration HCl using soda, lime or potassium hydroxide;

 conversion of copper and iron ions into an inactive form, for example, the binding of copper into complexes with the help of amines.

Depending on the process temperature, all methods thermal processing MSW that have found industrial application or have undergone experimental testing can be divided into two large groups:

 processes at temperatures below the melting point of slag;

 Processes at temperatures above the melting point of the slag.

Layered MSW combustion is carried out on moving grates (grate and roller) and in rotating drum kilns.

3.1. Layer burning.

Burning on grates.

All grates are installed in a furnace, which is a combustion chamber, where waste and blast air are supplied as an oxidizer of organic substances.

Pusher screens with both direct and reverse material supply are a system consisting of movable and fixed grates for moving and mixing waste. Direct feed grates (translational-push grates) have a small angle of inclination (6–12.5 º) and push the material towards the slag discharge (in the direction of material movement). Reverse feed grates (reverse push grates) have a large angle of inclination (typically 21-25º) and push the material (lower waste layer) in the opposite direction to the slag discharge and waste transfer. In this case, part of the burning waste layer returns to the beginning of the grate, which intensifies the combustion process.

Burning on roll grates.

Layered combustion of MSW on roll grates is widely used in industrial practice. When using furnaces with roller grates, Borrowed from the practice of burning coal, the material is moved using rotating rolls (drums).

The operating experience of plants that implemented layered combustion of MSW in furnaces with roll grates made it possible to identify a number of shortcomings:

 unsatisfactory operation and negative environmental impact due to poor stabilization of the combustion process;

 often not achieved optimum temperature;

 large yield of underburnt;

 poor quality of slag;

 significant loss of ferrous metals;

 Operational complications when curb stone and large amounts of metal get into the furnace;

 the complexity of organizing effective gas cleaning in case of unstable combustion of waste, etc.

The mechanical introduction of European equipment designed for the direct combustion of unprepared municipal waste in Russia is unacceptable, since in the cities of the Russian Federation there is practically no waste collection.

Burning in drum kilns.

Rotary drum kilns for burning raw (unprepared) MSW are rarely used. Most often, these furnaces are used for burning special waste, including hospital waste, as well as liquid and pasty industrial waste that has an abrasive effect.

Drum ovens are installed with a slight inclination in the direction of waste movement. Furnace rotation speed from 0.05 to 2 rpm. Waste, air and fuel are supplied from the loading side. Slag and ash are discharged from the opposite end of the kiln. In the first part of the furnace, the waste is dried to a temperature of 400 ºС and then gasified and burned, usually at a temperature of 900–1000 ºС.

In the practice of waste incineration, drum kilns were previously often used as afterburner drums after grates.

The practice of using drum kilns as afterburner drums in waste incineration plants is considered obsolete and this technology is not included in the designs of new plants.

3.2. Burning in a fluidized bed.

Fluidized bed combustion is carried out by creating a two-phase pseudo-homogeneous "solid-gas" system due to the transformation of the waste layer into a "pseudo-liquid" under the action of an ascending gas flow sufficient to maintain solid particles in suspension.

The layer resembles a boiling liquid, and its behavior obeys the laws of hydrostatics.

It is believed that combustion in a fluidized bed in terms of environmental and economic parameters in some cases exceeds traditional layer combustion.

Furnaces for solid waste incineration in a fluidized bed provide the best mode of heat transfer and mixing of the material being processed, and these characteristics are superior to boilers with push grates. In addition, fluidized bed apparatuses do not have moving parts or mechanisms. However, the need to ensure the fluidization mode of the processed material imposes restrictions on its granulometric and morphological composition, as well as on the calorific value. In some cases, the process of combustion in a fluidized bed, especially in a circulating fluidized bed, is more expensive than layered combustion.

The productivity of furnaces for burning solid waste in a fluidized bed ranges from 3 to 25 t/h. The prevailing combustion temperature is 850–920 ºС.

Due to the fact that the temperature of solid waste combustion in a fluidized bed is 50–100 ºС lower than in layer combustion, the possibility of nitrogen oxide formation due to air nitrogen oxidation is significantly reduced, resulting in reduced NO emissions with exhaust gases.

The role of the coolant in fluidized bed systems usually performs fine-grained sand , the particle surface of which creates a large heating surface compared to traditional grate combustion.

After heating the sand with an ignition burner to a temperature of 750–800 ºС, the waste is fed into the fluidized bed, where it mixes with the sand and wears out during movement.

As a result of the good thermal conductivity of the sand, the waste begins to burn quickly and evenly. The heat released at the same time maintains the sand in a hot state, which allows you to work in autogenous mode without supplying additional fuel to maintain the combustion mode.

3.3. Burning at temperatures above the melting point of the slag.

Main disadvantages traditional methods of thermal processing of MSW are a large volume of exhaust gases (5000–6000 m 3 per 1 ton of waste) and the formation of significant amounts of slag (about 25% by weight or less than 10% by volume). In addition, slags have a high content of heavy metals and for this reason are only of limited use, mainly as bulk material in landfills.

To obtain a slag melt directly in the process of thermal processing of MSW, it is necessary to ensure that the temperature in the apparatus is higher than the slag melting temperature (about 1300 º C). This usually requires either the use of oxygen or the supply of additional energy. Replacing part of the blast air with oxygen at the same time reduces the amount of exhaust gases.

The most obvious way to increase the temperature of waste combustion is to reduce the content of the inert component (nitrogen) in the used oxidizer (air), the heating of which consumes a significant part of the released energy.

The second significant advantage of combustion in oxygen is the drastic reduction in the volume of flue gases and, consequently, the reduction in gas cleaning costs. In addition, the reduced concentration of nitrogen in the blast air makes it possible to reduce the amount of nitrogen oxides formed at high temperatures, the purification of which is a serious problem.

In the early 90s, Vanyukov metallurgical furnaces were proposed for the thermal processing of MSW at a temperature of 1350–1400 ºС. Combustion is carried out in a fluidized bed of bubbling slag melt, which is formed from CHPP ash and slag waste loaded into the furnace.

The mechanical transfer of this process for large-scale thermal processing of MSW cannot be carried out due to:

 the fact that the efficiency of the Vanyukov furnace is very low due to the high temperature of the exhaust gases (1400–1600 ºС);

 the fact that predominantly organic raw materials are processed for processing; MSW consists of 70–80% organic components. When heated, mineral substances pass into a liquid phase, and organic substances into a gaseous one,

 lack of large-scale testing of the process in relation to MSW, which does not allow working out: loading and unloading units; automation of the process, taking into account fluctuations in the composition of raw materials, the composition and volume of exhaust gases, etc.; autogeneity of the process in relation to the heat treatment of waste as a heterogeneous mixture of many components that differ in composition, size and calorific value. It should be noted that fluctuations in the composition of MSW are not comparable with fluctuations in the composition of powdered concentrates sent for smelting in the Vanyukov furnace. Careful averaging of fluctuations in the composition of concentrates makes it possible to achieve fluctuations within 0.5%, while the initial MSW is practically not amenable to averaging;

 high cost of the process and equipment.

Thus, it is most expedient to use combustion at temperatures above the slag melting temperature for processing not initial MSW, but for neutralizing slags or their enriched fractions formed in the thermal processes of MSW processing at temperatures below the slag melting temperature. The output of slag in these processes is 10–25% of the original MSW, which sharply reduces the required productivity of furnaces and allows periodically involving slag in processing.