Most household waste is packaging. Characteristics of municipal solid waste (MSW)
Characteristics of municipal solid waste (MSW)
In cities and other settlements, the most intensive accumulation of solid waste occurs, which, if not properly and untimely removed and neutralized, can pollute environment.
Seasonal changes in the composition of MSW are characterized by an increase in the content of food waste from 20 - 25% in spring to 40 - 55% in autumn, which is associated with a large consumption of vegetables and fruits in the diet (especially in the cities of the southern zone). ) from 20 to 1% in the cities of the southern zone and from 11 to 5% in middle zone.
MSW accumulation rates - this is the amount of waste generated per settlement unit of a person - for housing stock, one place in a hotel; 1 m 2 of retail space for shops and warehouses, per unit of time - day, year. Accumulation rates are determined in units of mass (kg) or volume (l, m 3)
The accumulation rates and composition of MSW are influenced by the following factors:
the degree of improvement of the housing stock (the presence of garbage chutes, gas, water supply, sewerage, heating systems),
number of floors, type of fuel for local heating,
development Catering, the culture of trade, the degree of well-being of the population, etc.,
climatic conditions (different duration heating period- from 150 days in the southern zone to 300 days in the northern one),
food specifics, etc.
The quality of the organic fertilizer or biofuel obtained in the process of MSW processing depends on the chemical composition of the original MSW.
An important indicator of the physical properties of MSW is density. The density of MSW in the well-maintained housing stock in the spring-summer season (in containers) is 0.18 - 0.22 t/m 3 , in the autumn-winter season - 0.20 - 0.25 t/m 3 . For various cities, the average annual value is O.19 - 0.23 t / m 3.
Solid waste has a mechanical (structural) cohesion due to fibrous fractions (textiles, wire, etc.) and adhesions due to the presence of wet sticky components. Due to the coherence, MSW have a tendency to free-form and do not wake up in a fixed grate with a distance between the rods of 20 - 30 cm. MSW can stick to a metal wall with an angle of inclination to the horizon up to 65 - 70 °.
Due to the presence of solid ballast fractions (ceramics, glass), MSW and compost are abrasive, i.e. the property of abrading mutually intersecting surfaces in contact with them. MSW have caking properties, i.e. during prolonged immobility, they lose their flowability and compact (with the possibility of leachate release) without any external influence. With prolonged contact, MSW has a correlating effect on the metal, which is associated with high humidity and the presence of solutions of various salts in the filtrate.
Depending on the load, the properties of MSW change as follows. When the pressure rises to 0.3 - 0.5 MPa, various kinds of boxes and containers break. The volume of MSW (depending on its composition and humidity) decreases by 5 - 8 times, the density increases to 0.8 - 1 t/m 3 . Within this stage, pressing devices used in the collection and removal of solid waste operate.
When the pressure rises to 10 - 20 MPa, intensive release of moisture occurs (up to 80 - 90% of all water contained in MSW is released). The volume of solid waste is reduced by another 2 - 2.5 times with an increase in density by 1.3 - 1.7 times. The material pressed to such a state stabilizes for some time, since the moisture contained in the material is not enough for the active activity of microorganisms. The access of oxygen to the mass is difficult.
With an increase in pressure to 60 MPa, the volume slightly decreases (mainly due to the extrusion of moisture) and the density of MSW practically does not increase.
Depending on the initial humidity and pressing conditions, moisture extrusion begins at a pressure of 0.4 - 1.0 MPa, which should be taken into account when developing devices for briquetting MSW.
MSW classification.
Municipal solid waste (MSW) in Russian Federation, are a coarse mechanical mixture of a wide variety of materials and decaying products, differing in physical, chemical and mechanical properties and sizes. Before processing, the collected MSW must be subjected to separation into groups, if it makes sense, and after separation, each group of MSW should be processed.
MSW can be divided into several compositions:
In terms of quality MSW are subdivided into: paper (cardboard); food waste; wood; black metal; non-ferrous metal; textile; bones; glass; leather and rubber; stones; polymeric materials; other components; screening (small fragments passing through a 1.5 cm grid);
Hazardous MSW include: waste batteries and accumulators, electrical appliances, varnishes, paints and cosmetics, fertilizers and pesticides, household chemicals, medical waste, mercury-containing thermometers, barometers, blood pressure monitors, lamps.
Some wastes (for example, medical, pesticides, residues of paints, varnishes, adhesives, cosmetics, anti-corrosion agents, household chemicals) pose a danger to the environment if they get through sewage into water bodies or as soon as they are washed from a landfill and get into ground or surface water. Batteries and mercury-containing devices will be safe until the case is damaged: the glass cases of devices break easily on the way to the landfill, and corrosion will corrode the battery case over time. Then mercury, alkali, lead, zinc will become elements of secondary pollution of atmospheric air, underground and surface waters.
Domestic waste is characterized by multicomponent and heterogeneous composition, low density and instability (the ability to rot).
According to the nature and degree of impact on the natural environment, they are divided into:
industrial waste, consisting of inert materials,
disposal of which is currently economically unjustified;
recyclable materials (secondary raw materials);
waste of the 3rd hazard class;
waste of the 2nd hazard class;
waste of the 1st hazard class.
Of the total amount of waste generated annually at the enterprises, the cities make up the majority of inert solid waste, and a small part - industrial toxic MSW.
MSW - Solid Household Waste.
Municipal solid waste (MSW) is goods that have lost their consumer properties, the largest part of consumer waste or just garbage. The amount of garbage is growing by 3% annually. Only in the CIS, the amount of MSW is about 100 million tons / year, and Russia accounts for more than a quarter of this volume. The problem of solid waste is especially acute in megacities. To study the methods of disposal of solid waste, there is a science - Garbology. Grabology considers each method of disposal in order to study the harm to the Environment. The study of the properties of MSW is associated with significant difficulties due to the large number of constituent components. This number changes depending on climatic conditions, season, terrain features, etc. At the same time, the morphological composition of solid waste varies significantly over the years. This is connected, of course, with the socio-economic situation of the population, and so on. In the autumn-winter period, the content of food waste exceeds the average value.
Composition of MSW
The composition of MSW is currently dominated by the following components:
- Paper - newspapers, magazines, cardboard, packaging materials
- plastics
- Food and plant waste
- Various metals (non-ferrous and ferrous)
- Glass
- Textile
- wood, sheet
- Rubber
Impact on wildlife
Landfills of household waste serve as a food source for synanthropic species - carriers of infection, primarily rats. Cans, bottles and other containers with organic residues can play the role of traps for wild animals and insects.
Waste burial, processing and disposal technologies
Separate collection of different categories of solid waste
Separate collection of different categories of waste determines the efficiency and cost of disposal of individual components. The most inconvenient for disposal are mixed waste containing a mixture of biodegradable wet food waste, plastics, metals, glass, and other components.
burial
The cheapest way to get rid of waste is to bury it. This method goes back to the simplest way - to throw something out of the house into a landfill.
History has shown that simply throwing unusable items out of the house cannot solve the problem. In the 20th century, it was necessary to move from the spontaneous creation of landfills to the design and implementation of special engineering facilities, landfills for the disposal of household waste. The project provides for minimization of environmental damage, strict observance of sanitary and hygienic requirements.
Burning
The most common method of MSW disposal is incineration followed by disposal of the resulting ash at a special landfill. The method has serious drawbacks, such as the formation of highly toxic chemical compounds, such as dioxins and furans. For neutralization, which requires a special temperature jump, the so-called "afterburning" (a sharp decrease in temperature by 700-800 degrees) There are quite a few waste incineration technologies - chamber, layered, in a fluidized bed. Garbage can be burned mixed with fossil fuels. The most dangerous from an environmental point of view is low-temperature combustion in boilers.
These are goods and commodities (including their fragments) that have lost their original properties and were thrown away by their owner. Along with industrial solid waste, they pose a great threat to the environment and must be recycled.
Household waste not only worsens the ecological situation, but is also a source of additional costs associated with its collection and disposal. As cities grow, these costs increase. To solve problems with MSW in the world, various technologies for their processing have been developed. The most environmentally friendly and technologically advanced solution is the separation of municipal solid waste and their subsequent use as secondary raw materials.
The problem of municipal solid waste
The accumulation of municipal solid waste is a dangerous problem. Territory pollution various types garbage is ubiquitous. A huge amount of it is scattered over the earth's surface in the form of fragments or clusters (dumps). Waste also enters the waters of the oceans.
A significant proportion of MSW are products of oil and gas chemistry. They are persistent polymer compounds with a long half-life. The most environmentally harmful of them is polyvinyl chloride (PVC), which is associated with a high content of chlorine in its composition. Construction waste, compared to polymers, poses a significantly lower threat to the environment.
Environmental risks associated with MSW
The impact of municipal solid waste on the biosphere is diverse, large-scale and negative in almost all cases. The options for the impact of MSW on the environment are as follows:
- Clogging the earth's surface with household waste. Cellophane bags and other types of household waste are an obstacle to plant growth, contributing to a decrease in biological productivity, the rate of soil formation. Household garbage located in water bodies, oceans and seas can affect the processes of evaporation from the surface of the water.
- Pollution of the environment by the decay products of MSW. This is the most serious of the environmental problems associated with household waste. When polymers break down, toxic compounds are released that poison the soil and groundwater. No less harmful are the products of their combustion. Many landfills constantly smoke, polluting the air, especially in densely populated areas. The most dangerous and specific for MSW is dioxin, which is released during the combustion of PVC products. It is considered the most toxic chemical compound known to science. Fortunately, the amount of dioxin released during combustion is not large enough to cause poisoning, however, its contribution to the overall pollution is quite significant.
In addition to polymer degradation and combustion products, various household chemicals, heavy metals, asbestos from slates, hydrocarbons and many other substances also contribute to the overall pollution. The consequences can be dire:
- Death of animals and fish. Studies have shown that birds and fish can ingest small plastic objects, sometimes resulting in their death as a result of the accumulation of this debris in the digestive system. Animals that feed on landfills are also at risk, because there is a high probability of poisoning.
- Deterioration of the hygiene situation. Garbage heaps often become a breeding ground for pathogens that can be transferred to other areas by rodents living there.
- Loss of aesthetic appeal of the area. Being among household garbage is not for everyone. Unsightly appearance, smells, the risk of catching an infection, water pollution in springs - all this can significantly spoil outdoor recreation.
- Climate impact. Plastic films and glass block the thermal radiation coming from the earth, causing a local greenhouse effect and an increase in the temperature of the earth's surface. Large accumulations of garbage are a fairly powerful source of methane, which, entering the atmosphere, enhances the greenhouse effect.
- Seizure of land. Landfills are the reason for the reduction of free space that could be used for construction, creating squares or parks. This problem is quite relevant, especially near large and medium-sized cities.
Classification of municipal solid waste
There is no single system for separating municipal solid waste into classes. Initially, MSW is a single common mass. However, municipal solid waste is very different in terms of chemical composition and physical properties Components. The most widespread among MSW are: metal, plastic, glass, wood, paper and cardboard. In many countries, it is the basis for separate disposal and recycling. In Russia, they are still thrown out in one mass and then stored at landfills.
Disposal of household waste
Disposal of solid waste involves the use of various methods. The most common methods currently used to dispose of solid household waste are:
- Processing by mechanical means.
- Burial of solid household waste at landfills (landfills).
- Waste incineration.
- Complex processing.
- The use of biotechnology.
Export is the traditional and most environmentally harmful way of "disposing" of MSW. In our country, he still occupies a leading position.
In order to reduce the volume occupied by waste in landfills, they are often set on fire, which leads to the spread of hazardous substances over large areas and the deterioration of air quality. The products emitted during the burning of landfills have a strongly pronounced unpleasant odor and are harmful to health. The size of landfills in our country is constantly increasing.
Waste recycling
At the moment, there are several methods of disposal. The main ways that help to process solid household waste are:
- Mechanical processing is a set of technological operations for grinding, pressing, briquetting. All this leads to compaction and a reduction in the volume of garbage up to 10 times, which makes it more convenient to transport and store it. However, such methods only simplify the problem of disposal, but do not solve it completely.
- Integrated waste processing involves the creation of waste sorting and waste processing enterprises. At the first stage, the waste is distributed depending on the type of material (glass, plastic, metal, etc.), and then sent for processing to the appropriate workshops. This method of disposal allows you to get rid of most of the MSW and get secondary raw materials.
- Biological processing methods make it possible to remove from the waste the most accessible organic part for the decomposition of microorganisms, which is converted into the so-called biohumus. To do this, use a cultural strain of red Californian worm.
Briquetting
Briquetting is advisable to carry out after the extraction of more valuable components. The remaining waste is mechanically compacted and packaged. Formed briquettes are more convenient in storage, transportation and disposal.
Composting
Composting is a biological method of processing, in which the disposal of solid waste is carried out by creating so-called compost heaps. Depending on the level of technology development, the period of compost formation is from 2-10 weeks to 1-3 years.
Use of waste as a secondary raw material
The best-preserved items are removed, brought to good condition and reused. This practice also operates in some Russian cities. Glass, iron, aluminum and other metals are melted down and can be reused. A significant part of paper waste can also be recycled.
From household waste in Russia is not carried out, since it is considered unprofitable. Moreover, our country has large deposits of oil and gas, which provide better quality raw materials.
Incineration of municipal solid waste
Incineration of solid waste allows you to get rid of large volumes of garbage, but it also has serious disadvantages. When burning plastic, harmful substances enter the air, the most toxic of which is dioxin.
For this reason, developed countries are now phasing out this method of waste disposal. An additional source of pollution during centralized incineration of MSW is the emission of soot, ash and the formation of unburned fragments, which can account for a third of the initial volume of household waste. All of them have a higher hazard class than the original MSW, and therefore require more stringent storage and disposal conditions.
To make waste incineration as beneficial as possible, attempts are being made in Western countries to use it as a source of electricity and heat. This reduces the need for fossil species. An example of such successful cooperation is in Vienna. They apply modern technologies which make the combustion process safer.
Collection of household waste in the Russian Federation
In Russia, the removal of solid waste from urban areas is regulated by Article 13 of the law on “production and consumption waste”. Standard metal containers (garbage bins) are used to collect household waste. This practice has been operating since Soviet times.
Typically, a trash can is located in the space between residential buildings. Currently, attempts are being made to organize separate waste collection, which is provided for in accordance with Article 13 of the above law. The division is made into the following categories: plastic packaging, textiles, paper, glass, metal, organic plant waste. However, at the moment, such separation of waste has not received mass introduction into everyday practice.
For the transportation of solid waste, special vehicles are used - garbage trucks. They differ in the following ways:
- by application: machines used in residential areas and vehicles designed to work with large waste (bulky waste);
- by body volume;
- according to the method of loading;
- by type of mechanical compaction of debris;
- according to the nature of the unloading of solid waste.
The purpose of transportation is the removal of municipal solid waste to landfills. In large cities, garbage collection is complicated by the large distance that the car must regularly cover.
Collection and temporary storage of waste
In our country, the collection of municipal solid waste is the most costly stage of their disposal. The long distances that a garbage truck must travel in major city, and great amount generated waste forces to take measures for the rational planning of the collection system. For the same reason, it is necessary to increase the tariff for garbage collection for legal entities. A large amount of additional waste is associated with the operation of commercial outlets, and funds for the removal of such garbage are often insufficient.
One of the possible solutions is the creation of stations for intermediate storage of solid waste, from where bulky waste can be transported to the disposal site using various vehicles, including trains.
Household waste sorting methods
When sorting waste, certain fractions are isolated from the total mass, which can be sent for recycling. For this, the following methods are used:
- magnetic separation. It is based on the use of powerful magnets that attract ferrous alloys. The recovery factor is about 90% of the total mass of metal in the waste.
- Electrodynamic separation. It is used to remove aluminum, bronze, brass. The recovery factor exceeds 80%.
- Aerodynamic separation is used to remove polymers and paper from the bulk of the waste. This method consists in creating a powerful air flow, as a result of which lighter fractions are separated from heavy ones.
- Ballistic separation is based on a sharp change in the speed and direction of movement of the site with waste, which allows you to separate the elastic components from the more viscous ones. This method can be used to remove glass and some other types of debris.
Despite the constant improvement of disposal methods, the amount of waste increases by 3% every year.
The environment has always been a source of resources for mankind, but for a long time its vital activity did not have a noticeable impact on nature. Only since the end of the last century, under the influence of economic activity, noticeable changes in the Earth's biosphere began to occur. They have now reached alarming proportions.
Scale of the problem
The rapid growth of population and the level of consumption of natural resources, the current pace of material production lead to thoughtless treatment of nature. With such an attitude, a huge part of the resources taken from nature is returned to it in the form of waste, harmful and unsuitable for further use.
Scientists have calculated that 5 tons of garbage are generated daily in the world, while its amount increases annually by 3% in volume. The accumulation of domestic waste on the surface harms the environment, polluting water, soil and atmosphere and threatens the possibility of the existence of all life on the planet in general. Therefore, one of the important issues around the world is the disposal of household waste.
Classification of household waste
Household waste can be classified according to several criteria.
So, according to the composition, household waste is conditionally divided into biological residues and non-biological waste (garbage).
- rats;
- cockroaches.
Cockroaches can be a peddler different kind diseases
Non-biological waste includes:
- paper;
- plastic;
- metal;
- textile;
- glass;
- rubber.
The process of decomposition of these wastes can last about 2–3 years and in most cases is accompanied by the release of toxic substances that harm the environment and humans.
According to the state of aggregation, waste is divided into:
- hard;
- liquid;
- gaseous;
- pastes;
- gels;
- suspensions;
- emulsions.
By origin, waste is divided into:
- Industrial - a type of household waste obtained as a result of production.
- Construction - are formed during construction and installation work, the production of work on the repair of roads, buildings, as well as during their demolition.
- radioactive waste.
- Municipal solid waste (MSW) is generated in the residential sector, trade enterprises, educational, health and social facilities.
These are goods that have lost their consumer properties over time and turned into garbage, and also include road and yard garbage as MSW.
The most significant part of household waste is MSW. For each type of waste, there are special ways to dispose of waste.
Waste recycling
The process of disposal of solid waste occurs in several stages:
- collection;
- transportation;
- accommodation;
- neutralization;
- burial;
- storage;
- processing;
- disposal.
First of all, the process of getting rid of garbage involves its careful sorting. The task of pre-sorting waste and their disposal is greatly facilitated by the separate collection of waste, promoted in most European countries.
Methods for the destruction of municipal solid waste
There are various options for its destruction. So, the main way to dispose of solid waste is burial at special sites (landfills).
At landfills, the destruction of irretrievable waste takes place - the processing of household waste, as a result of which they almost completely cease to exist as waste. The disposal method is not suitable for all types of MSW, but only for non-combustible waste or for substances that emit toxic substances during combustion.
The advantage of this method is that it does not require significant financial costs and the availability of large plots of land. But there are also disadvantages in the application of this method - this is the accumulation of gas during underground decay of waste.
Briquetting is a new, yet not very widely used in practice, way of getting rid of solid waste. It includes preliminary sorting and packaging of homogeneous waste into separate briquettes, and then their storage at specially designated areas (landfills).
Briquetting of waste makes it possible to significantly save space
The garbage packed in this way is pressed, which greatly facilitates its transportation due to a significant reduction in volume.
Briquetted waste is intended for further processing and possible use for industrial purposes. Along with such a method as the processing of municipal solid waste, when briquetting, they can be transported for disposal or disposal by thermal treatment.
In fact, this method is similar to the burial method, but in practice it has a number of advantages over it. The disadvantages of the method are that the heterogeneity of the emitted waste and the preliminary severe contamination in the garbage containers and the change in some components of the waste creates a great difficulty in briquetting.
And the high abrasiveness of components such as stone, sand and glass interfere with the pressing process.
Since these methods of recycling have a number of disadvantages, despite their low cost, the best option will be the complete disposal of garbage during its processing into recyclable materials and fuel, as well as its possible reuse.
A new way to dispose of waste
Garbage disposal
When recycling garbage (the Latin root utilis is useful), the waste can later be used for various purposes.
Waste to be disposed of includes:
- all types of metals;
- glass;
- polymers;
- yarn and fabric products;
- paper;
- rubber;
- organic household and agricultural waste.
The most efficient method of disposal today is recycling.
In other words, recycling is a special case of the concept of "utilization of municipal solid waste".
During recycling, waste is returned to the process of technogenesis. There are two options for recycling waste:
- Reuse of waste for its intended purpose after appropriate safe handling and labeling. For example, reuse of glass and plastic containers.
- Return of waste after processing to the production cycle. For example, tin containers - in the production of steel, waste paper - in the production of paper and cardboard.
Some types of waste that can no longer be used for their intended purpose are recycled, after which it is more expedient to return them to the production cycle as secondary raw materials. So, part of the waste can be used to produce heat and electricity.
In addition to those already listed, the disposal of solid waste can be carried out by several more methods. Each of them is applicable to a certain type of waste, and has its own advantages and disadvantages.
Thermal processing of waste
Thermal processing refers to several methods:
- burning;
- low temperature pyrolysis;
- plasma treatment (high temperature pyrolysis).
The simple incineration method is the most common and one of the cheapest methods of waste management. It is during incineration that large volumes of garbage are utilized, and the resulting ash takes up less space, does not undergo decay processes, and does not emit harmful gases into the atmosphere. It is non-toxic and does not require specially equipped places for burial.
The main thing in this method is that when burning garbage, a large amount of thermal energy is released, which in recent times learned to use battery life waste incineration companies. And its surplus is redirected to city stations, which makes it possible to provide entire areas with electricity and heat.
The disadvantage of this method is that during combustion, in addition to safe components, smoke saturated with toxic substances is formed, which creates a dense curtain over the earth's surface and leads to a significant violation of the ozone layer of the atmosphere, contributing to its thinning and the formation of ozone holes.
High temperature and low temperature pyrolysis
is a waste gasification process that takes place at a melting temperature higher than in a conventional processing plant (over 900°C).
As a result, a vitrified product is formed at the outlet, which is absolutely harmless and does not require further disposal costs. The scheme of this process allows to obtain gas from the organic components of the scrap, which is then used to generate electricity and steam.
The main advantage of this method is that it allows you to successfully solve the problem of environmentally friendly waste disposal without unnecessary costs for preliminary preparation, sorting, drying.
The advantages of low-temperature pyrolysis (temperature from 450 to 900°C) are:
- use for processing almost all types of household waste, previously carefully selected;
- obtaining pyrolysis oils used in the production of plastics;
- release of pyrolysis gas suitable for further use.
In addition, there is such a waste disposal method as composting. Since most of the waste is made up of various organic residues, they are subject to rapid decay in the natural environment.
The composting method is based on this property of organic substances. In the process of composting, not only does a huge part of the garbage that pollute the environment get rid of, but also substances useful for agriculture - fertilizers - are obtained in the process.
The presented methods of waste disposal allow waste processing with the least negative impact on the environment.
Video: A modern approach to waste disposal
"Separate waste collection"
The basic idea |
Modern world produces a huge amount of waste. Many of them can be reused. Only what cannot be recycled should end up in the landfill. If we do not change our attitude towards garbage, the planet may turn into one big garbage dump. |
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Duration |
45 minutes. |
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materials |
Various types of packaging, from simple and multi-component materials: glass, aluminium, plastic, wood, paper, milk bags, film-coated paper, etc. |
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Related subjects |
Ecology, chemistry, biology. |
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Target lessons |
To form in students an awareness of the problems of proper handling of production and consumption waste, and practical skills for the economical consumption of these resources. |
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Tasks |
Motivate the need for personal participation of students in solving problems of resource conservation. Promote a culture of recycling household waste. Learn more about the different types of packaging and everyday materials. D. When purchasing gift wrapping for a friend, you pay attention to: - for the bright design of the packaging ( 3) ; - on the packaging material, its large amount ( 4 ); - the presence of eco-labels indicating the possibility of processing ( 2 ); -
pack a gift in an already used box or bag, after decorating them with improvised means ( 1
).
The teacher summarizes
:
The Ecological Footprint measures the impact humankind has on the environment. It shows us how much of the land and water surface is used for the production of food, raw materials, energy, as well as for the disposal of waste generated during this production process. The modern world produces a huge amount of waste. Many of them can be reused. Only what cannot be recycled should end up in the landfill. If we do not change our attitude towards garbage, the planet may turn into one big garbage dump. For many millennia, landfills did not change their volumes, people almost did not produce excess waste - materials were expensive, everything that was possible was reused or recycled. Metals were melted down, organic waste was composted, and even scraps of old clothes were used. The situation remained unchanged until about the middle of the 19th century - during the scientific and technological revolution, new polymeric materials, rubbers and plastics were invented and widely used. They were cheap, convenient and, unfortunately, did not decompose naturally. The area of landfills began to increase steadily. The growth of industry and the material standard of living still leads to an avalanche-like increase in waste. In Moscow in 2013, about 32.6 million tons of production and consumption waste were generated. About 80% of waste is generated as a result of agriculture, mining and processing industries, energy and transport. The remaining 20% are of domestic origin. In Moscow, a huge proportion of construction waste is soil excavated during the construction of the subway - their volume has increased significantly in recent years. Household garbage, although it does not make up a large part of the volume of garbage, is a very hazardous type of waste for nature - after all, it is mostly materials that do not decompose in natural conditions. Most household waste (plastics, metals, paper, glass and food waste) can be reused. According to statistics, in Moscow, one family accounts for up to one and a half kilograms of household waste per day. Basically, these wastes are represented by packaging made of various materials. There are three ways waste disposal- burial at special landfills, burning and processing. All of them have their advantages and disadvantages. Garbage from the city is mostly taken to landfills near Moscow, at the moment there are about 210 of them, with an area of 50 to 60 hectares. The total landfill area is comparable to the area of four and a half states of Monaco or twenty Vatican. Rational waste management is an alternative to turning our planet into one big garbage dump. 2. The stage of acquiring new knowledge.
Explain what simple materials, such as wood, metals, glass, paper or synthetics, are increasingly being replaced by composite materials containing several layers. This improves the quality of the final product, but makes it difficult to recycle - after all, when processing, it is necessary to first divide the packaging into its component parts, and this is far from always possible. Pay attention to the labeling of plastic packaging. Most plastic products have a special icon - a number in a triangle, sometimes the sign is supplemented with a letter designation. This plastic label indicates what material this packaging is made of and whether it can be recycled.
Please note that in Moscowplastics labeled 3 and 7 are not accepted for recycling ("polyvinyl chloride" and "all other plastics"). 3R conceptIt is clear that the problem of an avalanche increase in the amount of waste must be addressed. More than 20 years ago, the 3R concept was formulated - in the first letters English words reduce (reduction), reuse (reuse), recycle (recycling). From the very name of this concept, its basic principles are clear. Reduce - c reduce consumption, do not strive to buy unnecessary things, do not chase after the novelties of progress, if the existing things fully meet their functions. Try to buy products with less packaging. R euse (reuse) - m many items can be reused - for example, printing on the back of paper, making crafts from recycled materials (a vase from a drink bottle, a pencil holder from a jar, etc.) And the third "R" recycle (recycling)- used materials can and should be recycled so that they are made into something new, useful, and not left to lie in a landfill as a dead weight. When buying goods, you should pay attention to the labeling of the packaging - will it be possible to hand it over for recycling later? B. Interactive conversation "What to do with garbage?"Reference information for the teacher: There are three ways in which waste can be disposed of. The first is landfills. The disadvantages of this method are obvious - large areas are needed, landfills spoil the landscape, materials from landfills will be practically impossible to use in processing. Incineration - on the one hand, the amount of garbage is reduced by several times and the problem of lack of space for landfills is almost solved. On the other hand, the resulting ash is highly toxic, it is necessary to take care of cleaning the exhaust at waste incineration plants, when synthetic materials are burned, the most dangerous substances - dioxins - are released. Devices, materials and equipment: Scales, separate bags for different types of garbage, a diary of observations. Goals. Analysis of the structure and dynamics of waste generated in the apartment over a certain period of time (before and after the application of the separate waste collection method) Progress: Collect the garbage that is generated in your family (class) within one day. Weigh paper, plastic, glass, and aluminum separately if possible. To make it easier, you can introduce separate waste collection at home. You can observe and count for a week, then find the arithmetic average for each type of garbage. Try to shop with a cloth bag for a week, buy products in economy packaging, recycle some items. Then take the same measurements. Put the results in a table and compare with the previous ones. Formulation of results: It is desirable to collect the results in a single table, for example, this: Weight Aluminum Plastic Paper Glass Other Total weight Day 2 Day … Total average: Per day:__________ During the week:_________ Per month:__________ In the case of measuring the volume of garbage, it should be indicated how much garbage was thrown away before compaction, whether the more careful attitude to the choice of packaging at the purchase stage somehow affected the volume of garbage. Questions for the task: How much garbage does your family throw away in a week, month, year? How long will the waste produced by you decompose in the ground? Can we use several different waste containers in our homes? Explain your point of view. What else can affect the amount of garbage thrown out? Using the data in the table, calculate how much the mass of waste that is removed from your apartment to municipal solid waste landfills will decrease with separate waste collection per week (month, year). |