Municipal solid waste is goods and commodities (including their fragments) that have lost their original properties and were thrown away by their owner. Along with solid industrial wastes, they pose a great threat to the environment and are recyclable.
Household garbage not only worsens the environmental situation, but also is a source of additional costs associated with its collection and disposal. As cities grow, these costs increase. To solve the problems with solid waste in the world developed various technologies for their processing. 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. Pollution of territories by various types of garbage is widespread almost everywhere. A huge amount of it is scattered on the earth's surface in the form of fragments or clusters (dumps). Waste also gets into the waters of the oceans.
A significant proportion of solid waste 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 chlorine content in its composition. Building debris, compared to polymers, poses a significantly lower threat to the environment.
Environmental risks associated with solid waste
The impact of municipal solid waste on the biosphere is diverse, large-scale and in almost all cases negative. The environmental impact options for MSW 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 waste located in bodies of water, oceans, and seas can affect evaporation from the surface of the water.
- Environmental pollution by solid waste decomposition products. This is the most serious environmental problem associated with household waste. During the breakdown of polymers, toxic compounds are released that poison the soil and groundwater. No less harmful are the products of their burning. Many landfills constantly smoke, polluting the air, especially in densely populated areas. The most dangerous and MSW-specific combustion product is dioxin, which is released during the burning of PVC products. It is considered the most toxic chemical compound known to science. Fortunately, the amount of dioxin released during combustion is not so high as to cause poisoning, however, its contribution to the total pollution is quite significant.
In addition to the decay and combustion products of polymers, various household chemicals, heavy metals, slate asbestos, hydrocarbons and many other substances also contribute to general pollution. The consequences can be terrible:
- The death of animals and fish. Studies have shown that birds and fish can swallow small plastic objects, which sometimes leads to their death as a result of the accumulation of this garbage in the digestive system. Animals eating in landfills are also at risk, because there is a high probability of poisoning.
- Deteriorating hygiene situation. Debris debris often becomes a breeding ground for pathogens that can be transported to other territories by rodents living there.
- Loss of aesthetic appeal of the area. Finding among household waste is not to everyone's liking. Unsightly appearance, smells, risk of catching an infection, water pollution in springs - all this can significantly spoil outdoor recreation.
- Climate Impact. Plastic films and glass block the heat 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, when released into the atmosphere, enhances the greenhouse effect.
- Land acquisition. Landfills are the reason for the reduction of free space that could be used for construction, creation of squares or parks. This problem is quite relevant, especially near large and medium-sized cities.
Solid Waste Classification
There is no single system for classifying municipal solid waste. Initially, solid waste is a single common mass. However, municipal solid waste is a very different component in terms of chemical composition and physical properties. The most common among MSW are: metal, plastic, glass, wood, paper and cardboard. In many countries, waste classification is the basis for separate disposal and recycling. In Russia, they are still disposed of in the same mass and then stored at landfills.
Household waste
Disposal of solid waste involves the use of various methods. The most common methods currently available for disposing of municipal solid waste are:
- Recycling by mechanical means.
- Landfill of solid household waste at landfills (landfills).
- Waste incineration.
- Complex processing.
- The use of biotechnology.
The removal of solid household waste to landfills is the traditional and most environmentally harmful way of “disposing" of solid waste. In our country, he still holds 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 to large areas and deterioration of air quality. The products emitted during the burning of landfills have a pronounced unpleasant odor and are harmful to health. The size of landfills in our country is constantly increasing.
Waste recycling
Currently, there are several disposal methods. The main ways that help recycle municipal solid waste are:
Mechanical processing is a set of technological operations for grinding, pressing, briquetting. All this leads to compaction and reduction of the volume of garbage up to 10 times, which makes it more convenient to transport and store. However, such methods only simplify the disposal problem, but do not completely solve it.
- Integrated waste management 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 California worm.
Briquetting
Briquetting is advisable to carry out after the extraction of more valuable components. The remaining garbage is mechanically compacted and packaged. Educated briquettes are more convenient in storage, transportation and disposal.
Composting
Composting is a biological processing method in which solid waste is disposed of by creating so-called compost heaps. Depending on the level of technology development, the compost formation period is from 2-10 weeks to 1-3 years.
Use of waste as a secondary raw material
The best preserved items are recovered, put in good condition and reused. This practice is also valid in some Russian cities. Glass, iron, aluminum and other metals are smelted and can be reused. A significant portion of paper waste can be recycled.
Plastics from household waste are not processed in Russia, as it is considered unprofitable. Moreover, in our country there are large deposits of oil and gas, which provide better raw materials.
Solid Waste Incineration
The incineration of solid waste allows you to get rid of large amounts 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 gradually abandoning this method of waste disposal. An additional source of pollution during the centralized combustion of solid waste is soot, ash and the formation of non-hollow burnt fragments, which can make up one third of the initial volume of household waste. All of them have a higher hazard class than the original solid waste, and therefore require more stringent storage and disposal conditions.
In order to make garbage burning as useful as possible, in Western countries attempts are being made to use it as a source for generating electricity and heat. This reduces the need for fossil species. An example of such successful cooperation is the waste incinerator in Vienna. They use modern technologies that make the combustion process safer.
Collection of household garbage 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”. To collect household waste, standard metal containers (trash can) are used. This practice has been in force since Soviet times.
Usually 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 separation is carried out in the following categories: plastic packaging, textile products, paper, glass, metal, organic vegetable waste. However, at the moment, such a separation of garbage has not received mass adoption in domestic practice.
Solid Waste Disposal
For transportation of solid waste use special machines - garbage trucks. They differ in the following ways:
- for use: cars used in residential areas and vehicles designed to work with large waste (bulky waste);
- body volume;
- by the method of loading;
- by type of mechanical compaction of garbage;
- by the nature of the discharge 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 machine must travel regularly.
Collection and temporary storage of waste
In our country, the collection of municipal solid waste is the most expensive stage of their disposal. The long distances that a garbage truck must travel in a large city, and the huge amount of garbage generated, makes it necessary to take measures for 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 the interim storage of solid waste, from where bulky garbage can be transported to the disposal site using various vehicles, including trains.
