Disposal of municipal solid waste

Introduction

The concept of "municipal solid waste" emerged with the development of urban life and the increase in the volume of goods consumed. At the beginning of the 19th century, with population growth and urbanisation, waste management in cities became a pressing issue. At that time, municipal waste consisted mainly of organic materials such as food scraps, textiles and wood, which decomposed by themselves.

With the development of industry and mass production of goods in the late nineteenth and early twentieth centuries, household waste began to include more and more materials that could not be easily recycled or decomposed in nature. During this period, the concept of "rubbish" emerged, referring to waste that had no value and had to be discarded.

Over time, as cities grew and consumption increased, so did the amount of waste. In the 1960s and 1970s, it became clear in developed countries that simply dumping waste in landfills or in nature was causing serious environmental problems. In response, waste management concepts emerged, including the concept of "municipal solid waste".

Thus, the concept of "municipal solid waste" has emerged as part of a waste management strategy aimed at minimising the negative impact of human activities on the environment. This concept encompasses different types of waste that require specific recovery and recycling methods in order to reduce their harmful effects on ecosystems.

Modern society is faced with the growing challenge of managing and disposing of municipal solid waste (MSW), which is a diverse and complex mixture of materials. Understanding the composition and characteristics of these wastes plays an important role in developing effective methods for their management and recycling. Morphological and chemical analysis of MSW is a key step in determining optimal treatment and disposal strategies for this type of waste.

Municipal solid waste includes the following components:

• Organic waste: food residues, wood and other materials of natural origin;
• Synthetic materials: paper, plastic, textiles, leather, rubber and others;
• Metallic materials;
• Glass;
• Other waste.

These components require a variety of handling and processing techniques to ensure they are managed and handled effectively.

The composition and content of these components in MSW varies depending on many factors, such as the economic development of a country, the standard of living of the population, the consumer culture and mentality of the population, and climatic conditions. For example, seasonal changes and weather conditions can affect the amount of organic waste, while the introduction of new technologies can change the composition of waste, increasing the proportion of materials such as paper and plastic.

The composition of MSW is gradually changing as a result of technological developments and changes in consumption patterns. For example, with the move to district heating, traditional components such as coal and slag are becoming rare in MSW.

At present, the increase in consumption is leading to an increase in landfill. The choice of recycling methods depends on the characteristics and treatment of the raw materials. The earlier additional elements of waste treatment are introduced, the more efficient municipal waste recycling becomes. For example, labelling of products helps to ensure proper disposal of residues after use, and the introduction of separate waste collection systems encourages proper treatment. When disposing of solid waste, it is important to choose the most appropriate method, including recycling, incineration or energy recovery. The main methods include:

·       Burial;

·       Briquetting;

·       Composting;

·       Various types of processing (chemical, mechanical, thermal).

Burial in landfills:

Landfill and dump are two terms often used to refer to places where waste is stored. Their definitions and differences are summarised below:

Landfill:

·       A landfill is a specially equipped area for the collection, sorting and disposal of municipal solid waste. Landfills are usually built away from populated areas because of the unpleasant odours and potential health hazards. Landfills usually use composting, incineration or chemical treatment methods to reduce the volume and harmfulness of the waste.

Dump:

·       A dump is an unorganised accumulation of waste in an open area, often without any treatment or sorting. Landfills are characterised by their direct impact on the environment - they often lead to soil, water and air pollution. Landfills can be a source of odours, attract pests and create conditions for fires.

Depending on the level of organisation and waste management, landfills may be more structured and controlled than dumpsites. Nevertheless, both terms are used to refer to places where waste is concentrated and both pose certain environmental and human health problems.

Landfill is considered the least preferred method of solid waste management. This is due to the large area occupied by a landfill and the heterogeneous composition of the waste. Even if the correct landfill technology is used, there is a high probability that landfill gas will be generated as a result of the interaction between waste in different states, e.g. rotten and fresh, liquid and solid.

Briquetting of rubbish:

Some industries produce production waste that cannot be recycled into secondary raw materials. For example, wood processing produces sawdust, shavings and dust. These residues are not suitable for recycling, but they can be used as fuel. This is done by compressing the waste into briquettes for easy storage and transport.

·       Biomass briquettes, also known as bio-briquettes or fuel briquettes, are fuel blocks made from biodegradable materials. They are produced by compressing various materials such as wood waste, straw, organic agricultural waste and other similar materials. Biomass briquettes are widely used mainly for heating and power generation.

·       Plastic briquettes, also known as polymer briquettes, are blocks made from recycled plastic waste. These briquettes can be used in industry as a source of energy or as a secondary raw material for the production of various plastic products.

·       Coal briquettes are fuel blocks produced from coal waste or biomass by thermal pressing. They have a high thermal efficiency and can be used for heating and power generation. This type of fuel is often referred to as 'clean coal' due to its higher purity compared to conventional coal. Coal briquettes have a number of advantages, such as longer burning time and less ash, making them an attractive option for energy needs.

·       Metal briquettes are compact blocks produced by pressing metal waste such as shavings or scrap metal. They are used in the metal industry and are an important source of secondary raw materials for the manufacture of metal products.

These are just a few examples of waste briquettes and there are many more depending on region, technology and recycling requirements.

Household waste composting:

One of the main methods for treating organic household waste is composting. To achieve optimal results, the waste must undergo a fermentation process under certain conditions

·       Or in a ventilated container, which corresponds to an aerobic process where access to oxygen nourishes the mass,

·       Or in a closed tank, which is an anaerobic process where decomposition takes place without access to oxygen.

·       For successful composting, it is also necessary to maintain an optimum ratio of nitrogen to carbon in the compost (1 to 4) and to control moisture and temperature levels.

The composting process can take from a few weeks to a year, depending on conditions and materials. The result of the process is a dry and homogeneous mass that can be used as fertiliser. This method is widely used at home with your own organic waste such as food scraps, grass clippings and leaves.

Application of recycling:

Recycling is the process of extracting secondary raw materials from certain types of waste that have properties comparable to those of the virgin material. These include materials such as glass, metals and polymers. The recycled material can be used to make new products or as an additive to other materials.

The properties of the secondary raw materials obtained from recycling metals depend on their type: precious metals remain unchanged, while others may be slightly degraded and used as additives. The same applies to polymers, the quality of which depends on their composition. Wood can only be reworked a limited number of times - usually not more than seven times - after which it gradually loses quality.

Thermal methods:

Thermal methods play an important role in waste treatment, as they are simple processes involving feeding the furnace and recovering the products of combustion. Different types of furnaces are used, ranging from simple, unfiltered furnaces to more sophisticated equipment capable of producing more useful materials. These methods include:

·       Incineration: also known as thermal treatment or incineration, is the process of destroying solid waste by burning it at high temperatures in specialised facilities called incinerators. The incineration process oxidises the organic and inorganic components of the waste, converting them into heat energy and gaseous products such as smoke, steam and other gases.

·       Pyrolysis: is the process of thermal decomposition of organic materials in the absence or very low presence of oxygen. This process takes place at high temperatures, typically between 400 and 800 degrees Celsius, and can be used to decompose a variety of materials, including municipal solid waste, plastics, wood and other organic materials.

·       Plasma treatment: an advanced waste management method based on the use of plasma discharge to break down organic and inorganic materials into their basic constituents, such as gases and solid residues, at high temperatures and low pressures.

 

Waste disposal in Uzbekistan.

General scheme of solid waste management in the Republic of Uzbekistan

In Uzbekistan, the issue of solid waste management remains topical and requires a comprehensive approach for an effective solution. The country faces challenges related to population growth, increased consumption and changing lifestyles. In this context, understanding and optimising the waste management process plays an important role in keeping cities clean, preserving the environment and ensuring the health of citizens.

Since 2017, the Government of Uzbekistan has been actively taking measures to improve and develop the waste management system. The aim of these measures was to ensure environmental safety, rational use of natural resources and improve the quality of life of the population. The programme included the construction of modern waste collection, processing and disposal facilities, the introduction of advanced technologies and working methods, and the improvement of environmental awareness among the population.

In particular, Presidential Resolution from 21.04.2017 №PD-2916 "On Measures for the Cardinal Improvement and Development of the Waste Management System for 2017 - 2021" provides that:

·       Establishment of 13 state unitary enterprises "Toza Khududud" and their 174 branches in districts under the Ministry of Ecology, Environmental Protection and Climate Change of the Republic of Karakalpakstan and regional departments.

·       Transfer of 1,403 units of special equipment to the SUE "Toza Hududud" from territorial departments of improvement free of charge.

·       Implementation of the "Billing" system to create an electronic database of subscribers and records in all branches of SUE "Toza Hududud", as well as installation of GPS navigators in 1,174 units of special vehicles for online monitoring of their movements.

·       Transfer of 6131 waste collection points and 1102 containers to SUE "Toza Hudud" from territorial improvement departments free of charge. In 2017-2018, 322 new model waste collection points equipped with 2,651 containers were built, 9 vehicle fleets were built for SUE "Toza hudud" and the construction of another 18 vehicle fleets was started.

·       Transfer of 160 landfills to the State Unitary Enterprise "Toza Hududud". In 2017, 97 landfills were upgraded and in 2018 a further 100 landfills were upgraded.

Waste generation in 2017 for the Republic of Uzbekistan.

The city of Tashkent is the largest producer of waste - more than 700 thousand tonnes per year. According to the data provided in the "Strategy for solid waste management in the Republic of Uzbekistan for the period 2019-2028", approved by the Presidential Resolution of the Republic of Uzbekistan on 17 April 2019, 60% of this total is accounted for by waste from housing and communal services. This strategy provides for a number of measures to improve the sanitation infrastructure. The main directions are to ensure full coverage of the population with solid waste collection and disposal services, to create an efficient and modern system for its processing, and to reduce the volume of waste sent to landfills.

The strategy foresees the creation of modern landfills that meet sanitary and environmental standards, as well as measures to close and reclaim existing landfills. To improve the efficiency of the sanitation sector, it is planned to improve pricing and optimise tariffs.

The strategy also includes the use of solid waste facilities as alternative energy sources, reducing their environmental impact and supporting sustainable development in the region.

From 2024 to 2026 new waste management measures will be introduced in Uzbekistan. The Presidential Decree of the Republic of Uzbekistan from 04.01.2024 №PD-5 "On measures to improve the system of waste management and reduce its negative impact on the environmental situation" approved the project on implementation of "Phased organisation of the system of sorting of solid household waste". Within the framework of this project, a system of separate collection of household waste will be introduced in Tashkent and other regions of the country from this year.

These measures aim to encourage citizens to actively participate in waste sorting and recycling. The provision of free bags for waste collection and the opportunity to receive financial rewards for handing in recyclable materials is intended to make the process more convenient and attractive to the population.

The new system will be implemented at waste collection points near high-rise residential buildings in several Uzbek cities, including Tashkent, Angren, Andijan, Bukhara, Termez and Tashkent district. The system will separate waste into three categories: recyclable, non-recyclable and food waste.

By 1 July 2024, councils will be required to provide free rubbish bags with three types of QR codes to residents in these areas:

·       transparent for recyclable waste;

·       black for non-recyclable waste;

·       brown for food waste.

Conclusion:

Attempts to introduce separate waste collection in Tashkent began in 2012. The plan was to separate household waste into five categories, including hazardous waste such as mercury lamps. Local authorities were to install bins on streets and in public places, but the project was not fully implemented. In April 2019, the President of Uzbekistan approved a solid waste management strategy until 2028, with the aim of covering 100 per cent of the population with solid waste collection services and achieving a recycling rate of 60 per cent. In 2021, separate waste collection was to be introduced in several streets of Tashkent, and from 2023 the system was to cover all districts of the capital.

Municipal solid waste (MSW) management in Uzbekistan is an important environmental issue that requires a comprehensive and systematic approach by the state, local authorities, businesses and the public.

In recent years, the country has taken steps to improve the MSW management situation, including the development of a strategy and action plans. However, despite these efforts, there are problems in the implementation of these measures, such as insufficient funding, lack of necessary infrastructure, lack of awareness and passive participation of the population.

In order to successfully address the problem of MSW management, it is necessary to continue efforts to raise public awareness of the importance of proper waste management, to create and modernise infrastructure for waste sorting, recycling and disposal, and to develop a system of management and control of compliance with environmental standards.

At the same time, it is important to ensure transparency and openness in the process of decision-making and implementation of measures on MSW management, and to involve the public and local communities in the process of decision-making and implementation of measures to improve the environmental situation in the country.

MSW management should be seen as part of a broader strategy for environmental protection and sustainable development that will allow Uzbekistan not only to solve environmental problems but also to create favourable conditions for future generations.

 

References to information sources:

1.     https://anhor.uz/ekologiya/musornie-problemi-bolyshogo-goroda/

2.     https://uznews.uz/posts/52849

3.     https://ru.wikipedia.org/wiki/Твёрдые_бытовые_отходы#:~:text=Твёрдые%20бытовые%20%2F%20коммунальные%20отходы,также%20бывает%20производственным%20и%20строительным

4.     https://cleanbin.ru/utilization/solid/tko-waste

5.     https://www.gazeta.uz/ru/2024/01/08/waste/