Solid household waste is goods and objects.consumption (including their fragments), which have lost their original properties and were thrown out by their owner. Along with solid industrial waste, they pose a great threat to the environment and are recyclable.
Бытовой мусор не только ухудшает экологическую situation, but also is 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 solid household waste and their subsequent use as secondary raw materials.
The problem of solid waste
Accumulation of solid household waste - dangerousproblem. Contamination of territories with various types of garbage is common almost everywhere. A huge amount of it is scattered over the earth's surface in the form of fragments or clusters (dumps). Waste falls into the waters of the oceans.
A significant proportion of MSW are products of petroleum andgas chemistry. They are persistent polymeric 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. Compared with polymers, construction debris poses a significantly lower threat to the environment.
Environmental risks associated with MSW
The impact of solid household 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:
- Land litter is littered with household garbage.Cellophane bags and other types of household waste are an obstacle to plant growth, helping to reduce biological productivity and the rate of soil formation. Domestic garbage in water bodies, oceans and seas can affect evaporation from the surface of the water.
- Загрязнение окружающей среды продуктами распада MSW. This is the most serious of the environmental problems associated with household waste. With the disintegration of polymers, toxic compounds are released, which poison the soil and groundwater. No less harmful and their products of combustion. Many landfills constantly smoke, polluting the air, especially in densely populated areas. The most dangerous and specific for MSW combustion product is dioxin, which is released when burning PVC products. It is considered the most toxic chemical compound known to science. Fortunately, the volume of dioxin release during combustion is not so large as to cause poisoning, however, its contribution to the total pollution is quite significant.
In addition to the products of decomposition and combustion of polymersvarious household chemicals, heavy metals, slate asbestos, hydrocarbons and many other substances also contribute to the overall pollution. The consequences can be terrible:
- 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. At risk are animals that feed on landfills, because there is a high probability of poisoning.
- Deterioration of hygiene. Trash rubbish often becomes a breeding ground for pathogens that can be transported to other territories by rodents living there.
- Потеря эстетической привлекательности местности.Being among household garbage is not everyone's liking. Unsightly appearance, smells, the risk of catching an infection, water pollution in the springs - all this can significantly spoil the rest in nature.
- Impact on climate.Plastic films and glass trap thermal radiation from the earth, causing a local greenhouse effect and an increase in the temperature of the earth’s surface. Large accumulations of debris are a fairly powerful source of methane, which, entering the atmosphere, increases the greenhouse effect.
- Land seizure.Landfills are the reason for the reduction of free space, which could be used for construction, the creation of public gardens or parks. This problem is quite relevant, especially near large and medium-sized cities.
Classification of municipal solid waste
Unified system for the division into classes of solidhousehold waste does not exist. Initially, MSW is a single total 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 underlies the separate disposal and recycling. In Russia, they are still thrown away by the same mass and then stored at landfills.
Utilization of household waste
Disposal of MSW involves the use of various methods. The currently most common methods for disposing of solid household waste are:
- Recycling by mechanical methods.
- Burial of solid household waste at landfills (landfills).
- Waste incineration
- Integrated processing.
- The use of biotechnology.
Removal to the landfill of solid household waste is the traditional and most environmentally harmful way to "get rid" of solid waste. In our country, he still occupies a leading position.
In order to reduce the volume, which occupywaste at landfills, they are often set on fire, which leads to the spread of hazardous substances over large areas and deterioration of air quality. Products released 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.
Recycling
At the moment there are several methods of disposal. The main methods that help recycle solid household waste are:
- Mechanical processing is a combinationtechnological operations on crushing, pressing, briquetting. All this leads to compaction and reducing the volume of garbage up to 10 times, which makes it more convenient to transport and store. However, such methods only simplify the problem of disposal, but do not solve it completely.
- Integrated waste management impliescreation of waste sorting and waste recycling 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 allowremove from waste the most accessible for the decomposition of microorganisms organic part, which is converted into so-called biohumus. For this purpose, a culture strain of red Californian worm is used.
Briquetting
It is advisable to carry out briquetting afterextracting more valuable components. The remaining garbage is mechanically compacted and packaged. Formed briquettes are more convenient in storage, transportation and disposal.
Composting
Компостирование – это биологический способ recycling, in which the disposal of solid waste is carried out by creating the so-called compost heaps. Depending on the level of development of the technology, the period of compost formation varies from 2-10 weeks to 1-3 years.
Use of waste as secondary raw materials
The best preserved items are removed,are in good condition and reused. This practice is valid in some Russian cities. Glass, iron, aluminum and other metals are melted down and can be reused. Recycled can be a significant portion of waste paper.
Recycling plastics from household wasteRussia is not conducted because it is considered unprofitable. Moreover, in our country there are large oil and gas fields, which provide better quality raw materials.
Solid Waste Incineration
Incineration of solid waste eliminates large volumes of garbage, but it also has serious drawbacks. When burning plastics, harmful substances get into the air, the most toxic of which is dioxin.
For this reason, in developed countries nowGradually abandon this method of waste disposal. An additional source of pollution in the centralized incineration of MSW is emissions of soot, ash, and the formation of non-cavity burned fragments, which can be one third of the initial volume of household waste. All of them have a higher class of danger than the initial MSW, and therefore require more stringent conditions for storage and disposal.
That burning garbage brings as much as possiblebenefits, 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 a successful cooperation is an incinerator in Vienna. They use modern technology, thanks to which the combustion process becomes safer.
Collecting household waste in the Russian Federation
В России удаление ТБО с территорий городов regulated by Article 13 of the law on "production and consumption waste". Standard metal containers (garbage can) are used to collect household garbage. This practice has operated since the Soviet times.
Usually a trash can is placed in space.between residential buildings. At present, attempts are being made to organize separate collection of waste, which is provided for in accordance with Article 13 of the above law. The separation is made in the following categories: plastic packaging, textiles, paper, glass, metal, organic plant waste. However, at the moment, such a separation of garbage has not received a mass introduction into domestic practice.
Removal of solid waste
For transportation of MSW use special machines - garbage trucks. They differ in the following ways:
- on application: cars used in residential areas and vehicles intended for working with large waste (bulky waste);
- in terms of body volume;
- by way of loading;
- by type of mechanical garbage compacting;
- the nature of the discharge of solid waste.
The purpose of transportation is to export solid household waste to landfills. In large cities, garbage collection is complicated by the large distance that the machine must regularly travel.
Collection and temporary storage of waste
In our country, the collection of solid wasteis the most costly 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 raise the tariff for garbage collection for legal entities. A large amount of additional waste associated with the work of commercial outlets, and funds for the removal of such garbage is often not enough.
One possible solution is to createStations for intermediate storage of MSW, from where bulky waste can be transported to the disposal site using various means of transport, including trains.
Ways to sort household waste
When sorting waste from the total mass, certain fractions are isolated that can be sent for recycling. To do this, use the following methods:
- Magnetic separation. It is based on the use of powerful magnets that attract alloys based on ferrous metals. The recovery rate is about 90% of the total mass of metal in the waste.
- Electrodynamic separation. It is used for the removal of aluminum, bronze, brass. The recovery rate exceeds 80%.
- Аэродинамическая сепарация используется для removal of polymers and paper from the total mass of waste. This method consists in creating a powerful air flow, as a result of which the lighter fractions are separated from the heavy ones.
- Ballistic separation based on a sharpchange the speed and direction of movement of the site with waste, which allows to separate the elastic components from the more viscous. This method can be used to extract glass and some other types of garbage.
Despite the continuous improvement of disposal methods, the amount of waste increases every year by 3%.
