Processing of solid household waste: thermal and biothermal. Methods of processing and disposal of solid household waste Methods of processing and disposal of solid waste

Wherever a person is and whatever he does, he always leaves behind trash. Everyone is familiar with household waste, because each of us uses a lot of different substances for our normal life, after which waste remains. Before listing and characterizing the methods of disposal of solid domestic waste, let us answer the question: "What kind of solid waste can there be?"

Types of solid and household waste

1. Organic: food, wood, leather and bone;
2. Non-organic: paper, plastic, metal, textile, glass and rubber.

Let's think about the harm each of these types of waste can cause separately:

Waste paper. Who doesn't use paper today? Paper itself is harmless, but no one throws away plain, blank paper. Basically, it is either covered with paints or impregnated with wax, but this already significantly delays the decomposition of paper up to 2-3 years. Decomposition may produce toxic gases.

Textile trash. The harm of synthetic material is obvious, so let's talk about natural ones. The decomposition process can take up to 2-3 years. But on the other hand, he does not harm either nature or man.

Metal and glass debris. Iron cans and various glass shards decompose from several tens to several hundred years. When the metal decomposes, iron oxides and dioxides enter the soil and water, polluting them. When glass breaks down, it forms a glass crumb similar to sand. In addition, jars and fragments are dangerous with their sharp edges, both for the bare feet of a person and for an animal. They can also serve as a reservoir for water, where mosquitoes will eventually breed.

Plastic. It decomposes for several decades and longer. During decomposition, they release toxic substances that disrupt normal processes in soil and water, which will certainly affect not only humans, but also nature as a whole. Swallowing plastic pieces by animals can lead to their death.

As you read these lists, you probably wondered how much variety your bin contains. But that's not the worst part! The amount of waste allocated by us every year increases by 3% from the previous annual volume. Some scientists state that on average 1 person throws about 250kg of garbage per year! Now the question arises - "How is it going?"

Methods of disposal of solid household waste

There are actually several disposal methods. Each of them has advantages and disadvantages, so each of these methods has a right to exist.

This method is considered one of the most productive and safe and is based on the fact that garbage is literally given a “second life”. To begin with, it is necessary to sort waste from a heterogeneous mixture of waste, according to their belonging. Such sorting allows you to select from waste such valuable substances as non-ferrous and ferrous metals, glass and plastic, i.e. something that undergoes decomposition for the longest possible time and at the same time releases a mass of toxic substances.

In some European countries, the separate collection of waste is promoted, which greatly facilitates its disposal. After sorting the remaining:

• organic waste goes to recycling and turns into thermal energy and organic fertilizer;
• inorganic waste is used for the synthesis of building materials;
• the separated metal is pressed, packaged and sent to the foundry;
• glass waste goes to the production of technical glass, which is widely used in construction;
• plastic is also recycled and converted to plastic again.

But this process turns out to be unprofitable, since a lot of money is spent on cleaning it, and subsequently the secondary material is more expensive than the original, which makes it uncompetitive.

Thus, about 70% can be used. solid waste and even more. In addition, the production of secondary raw materials can bring a good profit, which again speaks of the advantage towards recycling waste into secondary raw materials.

2. Waste incineration

Disposing of solid waste through heat treatment is a common and one of the cheapest methods of waste management. There are several types of incineration:

• Layer;
• Chamber;
• In a fluidized bed.

The most dangerous incineration is heat treatment at low temperaturesoh. Combustion should take place at temperatures above +850 ° С, because it is at these rates that the residues of waste are “burned out” and the toxic substances in the emitted smoke are partially neutralized.

At the initial stage, pre-sorting of waste is again required. This is due to the fact that some materials, when burned, emit a lot of toxic substances into the atmosphere, poisoning not only nature, but also our health. Therefore, the waste is pre-sorted out, metal debris is eliminated, sending it for remelting, various batteries, plastic, accumulators, etc., dramatically reducing the formation of dioxins and furans in the process of waste combustion.

Incineration reduces the total amount of waste by 10 times, thereby reducing waste water and soil pollution. Also, the incineration process makes it possible to simultaneously utilize a large volume of waste, which is very convenient in large enterprises and cities, because allows you to resort to it as waste arrives.

The disadvantage of incineration is that during combustion, smoke is formed, saturated with toxic substances, which envelops the surface of the earth in a dense curtain, provokes a thinning of the ozone layer and the appearance of ozone holes and, as a result, various diseases in people. In addition to gas, two more components are formed during combustion - ash and slag, which make up about 30% of the original substance. The disposal of these substances is very problematic because they are also highly toxic.

3. Burial

Disposal of municipal solid waste through landfill is the oldest and cheapest method. The essence of the method is the usual burial of heterogeneous debris in the upper layer of the earth. For such burials, special areas of land are selected - landfills, which must meet certain requirements:

• Location from agricultural and residential areas from 200m and more, from forest areas - from 500m;
• The site should be located in an open and well-ventilated area that is free from construction and where there is the possibility of carrying out any engineering work;
• The possibility of creating a sanitary protection zone around a potential site - a landfill, occupying about 300m;
• A potential burial site should have one high-quality transport highway not far from itself, which is connected with other roads for smooth and quick exit and entry.

The advantages of this method of disposal are relative cheapness; also, disposal does not require the capture of large areas of land and large and constant financial costs.

The disadvantages are that the wastes that were buried in the soil, decomposing, poison it, thus it is impossible to carry out either agricultural or cattle-breeding work on such a plot of land, and new construction cannot be carried out. In addition, during decomposition, waste releases a mass of toxic substances onto the surface of the earth, which again adversely affects human and animal health. I would also like to note that interesting factthat the fight against the consequences of decomposition products, the costs of improving this piece of land requires much more financial costs than the costs that will be required for the construction of an organization that will subsequently be able to process solid household waste into secondary raw materials and fuel.

4. Briquetting

Disposal of solid waste by briquetting is a relatively new approach to solving the problem of waste disposal. It consists in packing homogeneous waste into separate briquettes, which reduces the volume of waste by about half, and pre-sorting allows you to put aside the components that will go for recycling. After packaging the waste, the materials are pressed, which subsequently reduces their total volume even more and facilitates transportation.

Briquettes with garbage are taken out for disposal by heat treatment or they are simply stored in specially designated landfills. In principle, the work is simple and by its nature vaguely resembles the previous method of disposal - burial. But the whole difficulty of briquetting lies in the heterogeneity of the waste released. In addition, during the stay of waste in containers, they become even more contaminated, change under the influence of an aggressive environment, adhesion of some waste components and high abrasiveness due to components such as stone, sand, glass, which prevents the pressing process.

5. Composting

As is already clear from all of the above, solid waste disposal methods have a lot of advantages and disadvantages. Composting is rightfully ideal method disposal of solid waste. More precisely, a decrease in the volume of solid waste, since substances such as metal, glass, plastic and processed paper are not composted. Thus, composting is the reuse of organic waste after its pretreatment with microorganisms to organic fertilizers. The end product is used to improve the quality and fertility of the land, and is widely used for gardening and horticulture.

You can make compost yourself, with your own hands at home. To do this, you need: organic waste, land from your garden, water and air. And if you add a little more heat, the process will go a little faster. Microorganisms that live in the earth convert waste into humus and bioactive substances. If you regularly turn over and water the compost heap, the decomposition product of your litter will be completely finished in 2–3 weeks. And in order for the compost to be as efficient and balanced as possible, you need:

• Make sure the heap is 1.5m high and wide. This will create a certain favorable balance of temperature and moisture;
• Regular access to moisture and air. This promotes the development and active reproduction of bacteria;
• The optimum carbon and nitrogen content is 30: 1. Lignified materials are rich in carbon, and fresh droppings or manure, grass cuttings and bone meal are rich in nitrogen;
• For complete decomposition of all garbage, it is necessary to grind it. This will help to make the compost as homogeneous as possible when processing microorganisms;
• Don't forget to add some soil, which is rich in microorganisms. You can take it from your garden.

Disposal methods for household waste differ in a variety of methods. But if you look at all these methods separately, then together they are able to dispose of waste with minimal harm to environment and for our health. Only for this, it is necessary to independently sort the garbage so that there are no problems with material contamination and there are no problems with their subsequent processing.

Isn't it so difficult to put paper in a pile, broken glass in a bucket, and tie food waste in bags? Think about it! Let's make sure that our children get a planet free of disease and a poisoned atmosphere!

The most widespread method of disposal of solid waste is incineration followed by burial of the resulting ash in a special landfill. There are quite a few technologies for waste incineration - chamber, layer, fluidized bed. Garbage can be burned in a mixture with natural fuel.

Thermal processing: process, advantages and disadvantages

Burning method (or in general view thermal methods for neutralizing solid waste) has both undoubted advantages (you can use the heat of combustion of solid waste to generate electricity and heat buildings, reliable disposal of waste), and significant disadvantages. A good system for cleaning flue gases is required, since when MSW is burned, hydrogen chloride and fluoride, sulfur dioxide, nitrogen oxides, as well as metals and their compounds (Zn, Cd, Pb, Hg, etc., are emitted into the atmosphere, mainly in the form of aerosols) ) and, which is especially important, in the process of waste combustion, dioxins, biphenyls are formed, the presence of which in the exhaust gases significantly complicates their purification due to the low concentration of these highly toxic compounds.

A variation of the incineration process is pyrolysis - thermal decomposition of solid waste without air access. The use of pyrolysis makes it possible to reduce the impact of solid waste on the environment and obtain such healthy foodsas combustible gas, oil, resins and solid residues (pyrocarbon).

The process of high-temperature processing of household and industrial waste in a bubbling slag melt is widely advertised (Fig. 1). The main unit of the technological scheme is a bubbling furnace, the design of which was developed in collaboration with specialists from the Stalproekt Institute (Moscow).

The furnace is simple and has small dimensions, high productivity and high operational reliability.

The process is carried out as follows. Household waste is fed to the loading device periodically. The pusher throws them into a slag bath, which is blown with oxygen-enriched air. In the bath, the waste is quickly immersed in the intensively mixed foam melt. The slag temperature is 1400 - 1500 ° C. Due to intensive heat transfer, the waste is subjected to high-speed pyrolysis and gasification. Their mineral part dissolves in the slag, and metal objects melt, and the liquid metal sinks to the bottom. With a low calorific value of waste, to stabilize the thermal regime, small amounts of thermal coal are fed into the furnace as an additional fuel. Natural gas can be used instead of coal. To obtain a slag of a given composition, a flux is loaded.

Slag is discharged from the furnace through a siphon continuously or intermittently and fed for processing. Chemical composition slag can be adjusted within wide limits, obtaining compositions suitable for the production of various building materials - stone casting, crushed stone, concrete fillers, mineral fibers, cement.

The metal through the overflow enters the siphon and is continuously or in portions drained into the ladle and then transferred for processing or directly at the furnace is poured into ingots, or granulated. Combustible gases - products of pyrolysis and gasification of waste and coal, emitted from the bath, are afterburned over the bath by supplying oxygen-enriched air or pure oxygen.

High-temperature furnace gases (1400 - 1600 ° C) are sucked off by a smoke exhauster into a steam boiler for cooling and efficient use of their energy. Complete combustion of gases is carried out in the boiler. The cooled gases are then directed to the purification system. Before discharging them into the atmosphere, they are cleaned from dust and harmful impurities. High temperatures process, a rational combustion scheme, consisting in a combination of the redox potential of the gas phase and temperature conditions, cause a low content of nitrogen oxides (NOx) and other impurities in the flue gases.

Flue gases due to high-temperature combustion contain significantly less organic compounds, in particular dioxins.

The conversion of alkali and alkaline earth metals into the vapor-gas phase under the conditions of the process promotes the binding of chlorine, fluorine and sulfur oxides into safe compounds that are captured during gas cleaning in the form of solid dust particles. Replacing air with oxygen makes it possible to reduce the volume of flue gases by 2 - 4 times, facilitate their cleaning and reduce the discharge of toxic substances into the atmosphere. Instead of a large amount of ash residue (up to 25% with conventional combustion), containing heavy non-ferrous metals and dioxins, inert slag is formed, which is a raw material for the production of building materials. Dust removed from the furnace with flue gases is selectively captured at different cleaning stages. The amount of dust is 2 - 4 times less than when using traditional ovens. Coarse dust (up to 60%) returns to the furnace, fine dust, which is a concentrate of heavy non-ferrous metals (Zn, Pb Cd, Sn, etc.), is suitable for further use.

Modern methods of thermal processing of solid household waste

Institute "Gintsvetmet" together with others russian organizations a technology for thermal processing of solid waste in a bubbling slag melt has been developed. Its main advantage is the solution to the current worldwide dioxin problem: already at the outlet of the bubbling unit, there are practically no highly toxic compounds (dioxins, furans, polyaromatic hydrocarbons). At the same time, there are now a number of domestic and foreign methods of thermal processing of solid waste, which are at different stages of development. The table shows the main indicators of thermal methods for processing solid waste, which are best known to ecologists and specialists in the disposal of such waste. These methods have either already received industrial distribution or have undergone large-scale approbation. The essence of the processes used:

• cD process - incineration of solid waste in a grate furnace (KR) or a boiler unit on grate grates of various designs;
• cOP process - incineration of waste in a fluidized bed (CC) of inert material (usually sand of a certain size);
• piroxel process - electrometallurgical, including drying, pyrolysis (incineration) of waste, processing of the mineral residue of combustion in the slag melt, as well as dust and gas cleaning of flue gases;
• process in a unit such as a Vanyukov furnace (PV) - melting in a bubbling melt;
• a process developed at the Institute of Chemical Physics of the Russian Academy of Sciences - combustion - gasification of waste in a dense layer of lumpy material without its forced mixing and movement;
• thermoselect process - combined, including the stages of compaction of waste, pyrolysis and high-temperature gasification (with the production of synthesis gas, inert and some mineral products and metals);
• siemens process - pyrolysis - combustion of pyrogas and separated carbonaceous residue using a blast not enriched with oxygen.

Combustion of solid waste in furnaces-boilers (KR process), due to relatively low temperatures (600 - 900 ° C), practically does not solve the dioxin problem. In addition, this results in the formation of secondary (solid unburned) slags and dust, which require separate processing or sent to disposal with subsequent negative consequences for the environment. These shortcomings are to some extent inherent in the process of KS. This adds the need to prepare raw materials for processing in order to comply with the particle size distribution.

The disadvantages of the process developed by the Institute of Chemical Physics of the Russian Academy of Sciences include:

• the need for sorting and crushing waste to a certain size; addition and subsequent separation of the heat carrier of a given particle size distribution;
• the need to develop an expensive flue gas cleaning system - synthesis gas, which is a mixture of carbon monoxide and hydrogen.

The process of smelting solid waste in a bubbling melt (in a PV furnace) should be noted (in addition to dioxin safety) two more advantages: a relatively high specific productivity and low dust emission. These indicators are due to the bubbling effect (intense gas blowing of the molten bath and the saturation of the spray in the working space of the furnace above the bath). An important positive factor is the availability of industrial experience in their operation at non-ferrous metallurgy enterprises in Russia and Kazakhstan. In general, it can be stated that the latest domestic development surpasses other domestic and foreign technologies for processing solid waste in terms of basic indicators and is a certain scientific and technical breakthrough in solving the global environmental problem.

Currently, one of the authors, under the leadership of the head of the diploma project, is developing a project for a solid waste landfill for st. Arkhonskaya North Ossetia-Alania, where there is an acute issue of unsatisfactory handling of solid household waste. When developing this project, the outlined ways of solving the MSW management will be taken into account and, first of all, the preliminary sorting of this waste and the extraction of polymer and other waste for further processing.

Biothermal MSW processing: Aerobic fermentation

Of the biothermal methods in practice, the most widespread is aerobic fermentation, which is often called composting (after the name of the end product of fermentation - compost used in agriculture).

Fermentation is a biochemical process of decomposition of the organic part of waste by microorganisms. In biochemical reactions, organic material, oxygen and bacteria interact (saprophytic aerobic microorganisms present in sufficient quantities in MSW), and carbon dioxide, water and heat are released (the material self-warms up to 60-70 ° C). The process is accompanied by the synthesis of humus. Reproduction of microorganisms-destructors of waste is possible at a certain ratio of carbon and nitrogen.

The best contact between organic matter and microorganisms is ensured by stirring the material, as a result of self-heating of which, during the fermentation process, most pathogens, helminth eggs, and fly larvae are destroyed.

According to the research results of British specialists, at the initial stage of fermentation, the mixture is mineralized, as evidenced by a decrease in the total carbon content of organic matter and humic acids. The resulting biomass has a high degree of polymerization and is characterized by a significant (compared to soil) concentration of nitrogen. During fermentation, the content of phenol groups in the biomass decreases and the content of HOOC and C \u003d 0 groups increases.

As a result of the completed fermentation process, the mass of biodegradable material is halved and a solid stabilized product is obtained.

Composting after the disposal of solid waste in world practice has developed as an alternative to incineration. The ecological task of composting can be considered the return of part of the waste to nature's circulation.

The most intensive composting of solid waste developed from the late 60s to the early 80s, mainly in countries Western Europe (Italy, France, Netherlands). In Germany, the peak of plant construction fell on the second half of the 1980s (in 1985, 3% of solid waste was processed into compost, in 1988 - about 5%). Interest in composting again increased in the mid-90s on the basis of the involvement in processing not of solid waste, but of selectively collected food and plant waste, as well as waste from the garden and park complex (thermal processing of this waste is difficult due to high humidity, and burial is associated with uncontrolled formation of filtrate and biogas). In European practice, by 2000, with the use of aerobic fermentation, about 4.5 million tons of waste were processed annually at more than 100 plants (of which 60 plants were built in 1992-1995).

In the CIS countries, direct composting of raw MSW is used at nine factories: in St. Petersburg (the first plant in the former USSR, built in 1971; at the end of 1994 in St. Petersburg, a second plant was commissioned), Nizhny Novgorod, Minsk and Mogilev, Tashkent, Alma-Ata, Tbilisi and Baku (all plants were designed by the Giprokommunstroy Institute, Mogilev - by the Belkommunproekt Institute). In 1998 a plant in Togliatti was put into operation, where preliminary but ineffective sorting of solid waste was implemented.

It should be noted that, due to the heterogeneous composition of waste, direct composting of MSW is impractical, since the resulting compost is contaminated with glass and heavy metals (the latter, as noted, are contained in hazardous household waste - spent galvanic cells, fluorescent lamps).

In the first mechanized industrial plants, MSW was most often composted in piles, periodically subjecting the material to tedding.

Currently, there are three aerobic fermentation methods most common in the industry:

• fermentation (composting) in bio drums;
• tunnel composting (fermentation);
• fermentation (composting) in the aging pool.

In the CIS, since 1971, only composting in bio drums has been practiced (in the mode of loading and unloading material, the rotational speed of the bio drum is 1.5 min1, the rest of the time is 0.2 min1). In Russia (a plant in Togliatti) on the basis of cement kilns, bio-drums of two standard sizes are produced - 36 and 60 m long; diameter of bio-drums - 4 m.

Due to the fact that the population is growing in the country, the demand for consumer resources is also increasing. As a result, an increase in resource consumption also increases the amount of household waste materials.

Garbage dumps are expanding every year and occupy an ever larger area, reservoirs are polluted due to wastewater, which carry many infections and elements dangerous to nature. Therefore, the utilization of household waste, in our time, should be developed no less than the industry, so that the generated solid waste (waste) could not accumulate and pollute the soil, atmosphere and water.

It is quite a logical fact that without the timely introduction of innovative technologies for recycling waste, the planet will soon turn into a huge dump and become unfit for the existence of not only people, but all living beings.

In order to avoid such a result, scientists in many countries have long been looking for optimal ways to deal with waste, thanks to which it would be possible to destroy or recycle solid waste without harm to the environment, as well as to rid the territorial space of huge volumes of garbage.

To date, the disposal of solid household waste is carried out by the following well-known methods that allow you to get rid of garbage:

• Burial or temporary storage of waste at special landfills. Sorting and unusable materials are carried out here, they are covered with earth.
• Composting. Natural decomposition of biological substances, their processing into mineral fertilizers for soil and planting crops.
• Heat treatment of solid waste. This method allows you to burn almost any type of waste, which minimizes their volume as much as possible, and also provides economic benefits in the form of thermal energy.
• Low temperature and high temperature pyrolysis.

Solid waste disposal methods

Burial of solid waste

Disposal of solid waste by landfill is one of the most common methods today to get rid of garbage. But this method is widespread only among non-combustible waste, as well as among those substances that can release toxic elements during combustion.

The solid waste landfill is an unusual landfill, it is equipped with all modern engineering structures that allow systems to combat and groundwater isolate all harmful substances. This also applies to the atmosphere, that is, there are practically no leaks of any chemical and toxic elements, which is the main goal to ensure the safety of the country's ecology.

But there are also disadvantages in such methods, for example, the formation of gas in the process of rotting debris. Some are equipped with special equipment for pumping gas, which, as it should be noted, is later used to generate electricity. And it allows the equipment that is located on landfills to operate almost independently. But unfortunately, so far in Russia, only a small part of all such landfills are equipped with such equipment, while all other waste sites do not have the ability to deal with gas emissions.

But even taking into account the presence of such installations, the ecology remains unprotected from the effect of debris decomposition in the soil, and all secretions in the process of decay and fermentation. Since the buried material will completely disappear only after tens, or even hundreds of years. Therefore, despite the relative cheapness of this method of dealing with waste, for the environment, the best option is to completely get rid of garbage by recycling it and using it in the manufacture of any product. In the event, the risk of environmental pollution will be minimized.

Composting solid waste

Utilization of household waste by means of composting is a technology that allows, therefore, solid waste by natural biological decomposition. The main source of composting is organic substances and materials; this method is very actively applied to them. Composting not only makes it possible to get rid of a bulky substance that pollutes the environment, but also provides agriculture with fertilizers that are useful for the soil, allowing them to normalize the balance of minerals in the earth and grow various vegetables and crops.

But since this method does not allow to recycle most types of waste, requires a careful sorting process and takes quite a long time, it has not gained popularity in the country and is underdeveloped at the proper level. In Russia, there is not a single industrial enterprise that carried out composting in such volumes and made it possible to clean up at least one city from organic waste.

This method is often used only for individual purposes:

• in small farms;
• in garden plots;
• in private homes;
• in agricultural organizations;
• on livestock farms, etc.

However, this method does not require large expenses, although it does not cover all types and classes of waste material, it allows you to fully get rid of a huge part of the waste produced by the country, which takes up a third of all waste in the country. Establish a centralized process and carry out composting on special sites equipped with all the necessary buildings and structures. Build a kind of factories, for starters in large cities of the country, for the processing of solid waste and other organic waste. The end product, compost, will be very useful in many agriculture, and, most importantly, its cost will reduce the cost of growing many crops and provide funds for the operation of such plants.

Thermal processing of solid waste

With the help of heat treatment, the disposal of household waste allows you to get rid of organic fractions; this method is quite often used in large-scale volumes of waste generation. Thermal, represents several processes, in combination, allowing you to get rid of any non-toxic type of waste material or minimize them as much as possible in volume and mass. Also, heat treatment is carried out to neutralize devices, equipment and other things infected with infectious or epidemiological bacteria, which may have the following origin:

• medical institutions;
• laboratories;
• veterinary clinics;
• chemical plants;
• oil refining industry;

which later, having received an inert state, can be buried in special landfills or placed in temporary storage for further processing and reuse as raw material.

Important advantages of heat treatment or processing are modern methods that allow obtaining:

• effective disinfection or disposal of any waste material;
• complete destruction of any microflora and even pathogenic;
• reduction of waste in volume up to 10 times;
• use the energy potential of organic waste.

Of all the various methods of utilization or destruction of solid waste, the method of incineration can be considered the most waste-free. Since it destroys materials and substances of any volume and turns them into ash, which occupies hundreds of times less space and does not have the ability to rot and emit gases harmful to the atmosphere. Also, ash cannot be toxic, it is not afraid of temperature changes, it does not require specially equipped landfills for burial.

Incineration has many advantages over other methods, it is worth highlighting the main ones, these are:

• high level of testing technologies;
• stably produced equipment and its long service life;
• the high-tech process is performed automatically;

but, most importantly, it is that recently, factories or organizations engaged in waste incineration receive heat energy or electricity that can be used for the autonomous operation of the enterprise. In some cases, surplus such energy is redirected to city stations, which ultimately allows entire areas to be supplied with electricity or heated.

Plasma processing of solid waste

Not as developed as the above listed methods and methods of disposal of scrap, but a very promising technological process that allows you to solve all ecological problems, utilize and ultimately provide useful and necessary energy for society.

The plasma processing technology uses a melting point much higher than any slag melting furnace. Thus, the output is a glazed product that is absolutely harmless and, most importantly, does not require further costs for neutralization or special disposal.

Plasma processing is a technology for gasification of waste, the scheme of this method, allows you to get gas from biological components of waste. The resulting gas is then used to generate electricity or steam. The main material for plasma processing is solid waste in the form of slag or neutralized residues.

The main advantage of high-temperature pyrolysis is the ability to dispose of waste in an environmentally friendly manner, without extra costs:

• for preliminary preparation;
• sorting;
• for drying, etc.

These qualities allow thermal processing to be rightfully considered the most environmentally and economically beneficial technology for the disposal of solid waste.

All these methods are designed to solve.

Also watch the video - how a solid waste recycling plant works

In our world, due to the fact that the population is constantly increasing, resource consumption is also growing steadily. And the consumption of renewable resources and non-renewable resources is accompanied by an increase in the amount of waste. Garbage dumps, pollution of water bodies - this is all that human life leads to.

And it is logical that without the use of innovative methods of waste recycling, there is a high probability that the planet will turn into one huge dump. And it is not surprising that scientists constantly come up with and implement in practice new ways of processing solid waste. What methods are used today?

1. Burial of waste at landfills. This includes

• Earthen backfill

2. Natural methods of solid waste decomposition. This includes

• Composting

3. Thermal processing of solid waste. This includes

• Burning
• Low temperature pyrolysis,
• High temperature pyrolysis (plasma processing)

Let's talk about everything in a nutshell.

Burial at landfills today is the most widespread method of waste disposal in the world. This method is applied to non-combustible waste and to such waste that, during combustion, emit toxic substances.

The landfill (MSW) is not an ordinary landfill. Modern landfills for disposal are complex engineering structures equipped with systems for combating groundwater pollution and atmospheric air... Some landfills are able to convert the gas formed during the decomposition of waste gas into electricity and heat. Unfortunately, today this applies to a greater extent to European countries, since in Russia a very small percentage of landfills meets these characteristics.

The main disadvantage of traditional waste disposal is that even with the use of numerous cleaning systems and filters, this type of disposal does not provide an opportunity to completely get rid of such negative effects of waste decomposition as rotting and fermentation, which pollute the air and water. Therefore, although in relation to other methods of disposal, the disposal of solid waste is quite cheap, environmentalists recommend to recycle the waste, thereby minimizing the risks of environmental pollution.

Composting is a waste recycling technology that relies on natural biodegradation. For this reason, composting is widely used for the processing of organic waste. Today there are technologies for composting both food waste and an undivided solid waste stream.

In our country, composting has not become widespread enough, and it is usually used by the population in individual houses or in garden plots. However, the composting process can also be centralized and carried out on special sites, which are a plant for the processing (MSW) of organic waste. The end product of this process is compost, which can be used in various agricultural applications.

Since household waste contains a fairly high percentage of organic fraction, thermal methods are often used to process MSW. Thermal processing of waste (MSW) is a set of processes of thermal impact on waste, necessary to reduce their volume and weight, neutralize, and obtain energy carriers and inert materials (with the possibility of recycling).

Important advantages of modern thermal processing methods are:

• effective disposal of waste (complete destruction of pathogenic microflora).
• reduction of waste volume up to 10 times.
• use of the energy potential of organic waste.

Incineration is the most widespread of all the variety that can boast of solid waste processing methods. The main benefits of incineration are:

• high level of technology approbation
• commercially available equipment.
• long warranty period
• high level of automation.

The main trend in the development of waste incineration is the transition from direct waste incineration to optimized incineration of the fuel fraction obtained from solid waste and a smooth transition from incineration as a waste disposal process to incineration as a process that provides additional generation of electrical and thermal energy. And the most promising today is the use of plasma technologies, due to which a temperature higher than the melting point of the slag is provided, which makes it possible to obtain a harmless vitrified product and useful energy at the output.

Plasma waste processing (MSW), in essence, is nothing more than a garbage gasification procedure. The technological scheme of this method involves the production of gas from the biological component of waste for the purpose of using it to generate steam and electricity. An integral part Plasma processing processes are solid products in the form of non-pyrolyzable residues or slag.

A clear advantage of high-temperature pyrolysis is that this technique makes it possible to cleanly and relatively simply from the technical point of view, to process and destroy a variety of household waste without the need for their preliminary preparation, i.e. drying, sorting, etc. And of course, the use of this technique today is more profitable from an economic point of view than the use of other, more outdated techniques.

In addition, when using this technology, the resulting slag is a completely safe product, and it can be used subsequently for a variety of purposes.

Due to the fact that the population is growing in the country, the demand for consumer resources is also increasing. As a result, an increase in resource consumption also increases the amount of household waste materials.

Garbage dumps are expanding every year and occupy an ever larger area, reservoirs are polluted due to wastewater, which carries many infections and elements hazardous to nature. Therefore, the utilization of household waste, in our time, should be developed no less than the industry, so that the generated solid waste (waste) could not accumulate and pollute the soil, atmosphere and water.

It is quite a logical fact that without the timely introduction of innovative technologies for recycling waste, the planet will soon turn into a huge dump and become unfit for the existence of not only people, but all living beings.

In order to avoid such a result, scientists in many countries have long been looking for optimal ways to deal with waste, thanks to which it would be possible to destroy or recycle solid waste without harm to the environment, as well as to rid the territorial space of huge volumes of garbage.

To date, the disposal of solid household waste is carried out by the following well-known methods that allow you to get rid of garbage:

• Burial or temporary storage of waste at special landfills. Sorting and unusable materials are carried out here, they are covered with earth.
• Composting. Natural decomposition of biological substances, their processing into mineral fertilizers for soil and planting crops.
• Heat treatment of solid waste. This method allows you to burn almost any type of waste, which minimizes their volume as much as possible, and also provides economic benefits in the form of thermal energy.
• Low temperature and high temperature pyrolysis.

Solid waste disposal methods

Burial of solid waste

Disposal of solid waste by landfill is one of the most common methods today to get rid of garbage. But this method is widespread only among non-combustible waste, as well as among those substances that can release toxic elements during combustion.

The landfill for the burial of solid waste is an unusual landfill, it is equipped with all modern engineering structures that allow the control systems and groundwater to isolate all harmful substances. This also applies to the atmosphere, that is, there are practically no leaks of any chemical and toxic elements, which is the main goal to ensure the safety of the country's ecology.

But there are also disadvantages in such methods, for example, the formation of gas in the process of rotting debris. Some are equipped with special equipment for pumping gas, which, as it should be noted, is later used to generate electricity. And it allows the equipment that is located on landfills to operate almost independently. But unfortunately, so far in Russia, only a small part of all such landfills are equipped with such equipment, while all other waste sites do not have the ability to deal with gas emissions.

But even taking into account the presence of such installations, the ecology remains unprotected from the effect of debris decomposition in the soil, and all secretions in the process of decay and fermentation. Since the buried material will completely disappear only after tens, or even hundreds of years. Therefore, despite the relative cheapness of this method of dealing with waste, for the environment, the best option is to completely get rid of garbage by recycling it and using it in the manufacture of any product. In the event, the risk of environmental pollution will be minimized.

Composting solid waste

Utilization of household waste by means of composting is a technology that allows, therefore, solid waste by natural biological decomposition. The main source of composting is organic substances and materials; this method is very actively applied to them. Composting not only makes it possible to get rid of a bulky substance that pollutes the environment, but also provides agriculture with fertilizers that are useful for the soil, allowing them to normalize the balance of minerals in the earth and grow various vegetables and crops.

But since this method does not allow to recycle most types of waste, requires a careful sorting process and takes quite a long time, it has not gained popularity in the country and is underdeveloped at the proper level. In Russia, there is not a single industrial enterprise that carried out composting in such volumes and made it possible to clean up at least one city from organic waste.

This method is often used only for individual purposes:

• in small farms;
• in garden plots;
• in private homes;
• in agricultural organizations;
• on livestock farms, etc.

However, this method does not require large costs, although it does not cover all types and classes of waste material, it allows you to fully get rid of a huge part of the waste produced by the country, which takes up a third of all waste in the country. Establish a centralized process and carry out composting on special sites equipped with all the necessary buildings and structures. Build a kind of factories, for starters in large cities of the country, for the processing of solid waste and other organic waste. The final product, compost, will be very useful in many farms, and, most importantly, its cost will reduce the costs of growing many crops and provide funds for the operation of such plants.

Thermal processing of solid waste

With the help of heat treatment, the disposal of household waste allows you to get rid of organic fractions; this method is quite often used in large-scale volumes of waste generation. Thermal, represents several processes, in combination, allowing you to get rid of any non-toxic type of waste material or minimize them as much as possible in volume and mass. Also, heat treatment is carried out to neutralize devices, equipment and other things infected with infectious or epidemiological bacteria, which may have the following origin:

• medical institutions;
• laboratories;
• veterinary clinics;
• chemical plants;
• oil refining industry;

which later, having received an inert state, can be buried in special landfills or placed in temporary storage for further processing and reuse as raw material.

Important advantages of heat treatment or processing are modern methods that allow obtaining:

• effective disinfection or disposal of any waste material;
• complete destruction of any microflora and even pathogenic;
• reduction of waste in volume up to 10 times;
• use the energy potential of organic waste.

Of all the various methods of utilization or destruction of solid waste, the method of incineration can be considered the most waste-free. Since it destroys materials and substances of any volume and turns them into ash, which occupies hundreds of times less space and does not have the ability to rot and emit gases harmful to the atmosphere. Also, ash cannot be toxic, it is not afraid of temperature changes, it does not require specially equipped landfills for burial.

Incineration has many advantages over other methods, it is worth highlighting the main ones, these are:

• high level of testing technologies;
• stably produced equipment and its long service life;
• the high-tech process is performed automatically;

but, most importantly, it is that recently, factories or organizations engaged in waste incineration receive heat energy or electricity that can be used for the autonomous operation of the enterprise. In some cases, surplus such energy is redirected to city stations, which ultimately allows entire areas to be supplied with electricity or heated.

Plasma processing of solid waste

Not as developed as the above listed methods and methods of disposal of waste, but a very promising technological process that allows you to solve all environmental problems, utilize and ultimately provide useful and necessary energy for society.

The plasma processing technology uses a melting point much higher than any slag melting furnace. Thus, the output is a glazed product that is absolutely harmless and, most importantly, does not require further costs for neutralization or special disposal.

Plasma processing is a technology for gasification of waste, the scheme of this method, allows you to get gas from biological components of waste. The resulting gas is then used to generate electricity or steam. The main material for plasma processing is solid waste in the form of slag or neutralized residues.

The main advantage of high-temperature pyrolysis is the ability to dispose of waste in an environmentally friendly manner, without extra costs:

• for preliminary preparation;
• sorting;
• for drying, etc.

These qualities allow thermal processing to be rightfully considered the most environmentally and economically beneficial technology for the disposal of solid waste.

All these methods are designed to solve.

Also watch the video - how a solid waste recycling plant works