Recycling point Gdansk University of Technology

Waste sorting is the process by which waste is separated into different elements. Waste sorting can occur manually at the household and collected through

curbside collection Kerbside collection or curbside collection is a service provided to households, typically in urban and suburban areas, of collecting and disposing of household waste and recyclables. It is usually accomplished by personnel using specially built ...

schemes, or automatically separated in

materials recovery facilities A materials recovery facility, materials reclamation facility, materials recycling facility or Multi re-use facility (MRF, pronounced "murf") is a specialized plant that receives, separates and prepares recyclable materials for marketing to end-u ...

mechanical biological treatment A mechanical biological treatment (MBT) system is a type of waste processing facility that combines a sorting facility with a form of biological treatment such as composting or anaerobic digestion. MBT plants are designed to process mixed househo ...

systems. Hand sorting was the first method used in the history of waste sorting. Until now this method is still used. Waste can also be sorted in a

civic amenity site A civic amenity site (CA site) or household waste recycling centre (HWRC) (both terms are used in the United Kingdom) is a facility where the public can dispose of household waste and also often containing recycling points. Civic amenity sites ...

. "Waste segregation" means dividing waste into dry and wet. Dry waste includes wood and related products, metals and glass. Wet waste typically refers to organic waste usually generated by eating establishments and are heavy in weight due to dampness. Waste segregation is different from waste sorting. Waste segregation is the grouping of waste into different categories. Each waste goes into its category at the point of dumping or collection, but sorting happens after dumping or collection. Segregation of waste ensures pure, quality material. Sorting on the other hand will end up producing impure materials with less quality.

Methods

Waste is collected at its source in each area and separated. The way that waste is sorted must reflect local disposal systems. The following categories are common: *

Paper Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, rags, grasses or other vegetable sources in water, draining the water through fine mesh leaving the fibre evenly distributed ...

Cardboard Cardboard is a generic term for heavy paper-based products. The construction can range from a thick paper known as paperboard to corrugated fiberboard which is made of multiple plies of material. Natural cardboards can range from grey to light b ...

(including packaging for return to suppliers) * Glass (clear, tinted–no light bulbs or window panes, which belong with residual waste) *

Plastics Plastics are a wide range of synthetic polymers, synthetic or semi-synthetic materials that use polymers as a main ingredient. Their Plasticity (physics), plasticity makes it possible for plastics to be Injection moulding, moulded, Extrusion, e ...

* Textiles * Wood, leather, rubber *

Scrap metal Scrap consists of recyclable materials, usually metals, left over from product manufacturing and consumption, such as parts of vehicles, building supplies, and surplus materials. Unlike waste, scrap has monetary value, especially recovered me ...

Compost Compost is a mixture of ingredients used as plant fertilizer and to improve soil's physical, chemical and biological properties. It is commonly prepared by decomposing plant, food waste, recycling organic materials and manure. The resulting m ...

* Special/

hazardous waste Hazardous waste is waste that has substantial or potential threats to public health or the environment. Hazardous waste is a type of dangerous goods. They usually have one or more of the following hazardous traits: ignitability, reactivity, co ...

Residual waste Municipal solid waste (MSW), commonly known as trash or garbage in the United States and rubbish in Britain, is a waste type consisting of everyday items that are discarded by the public. "Garbage" can also refer specifically to food waste, ...

Organic waste can also be segregated for disposal: * Leftover food which has had any contact with meat can be collected separately to prevent the spread of bacteria. ** Meat and bone can be retrieved by bodies responsible for animal waste. ** If other leftovers are sent, for example, to local farmers, they can be sterilised before being fed to the animals. * Peels and scrapings from fruit and vegetables can be

compost Compost is a mixture of ingredients used as plant fertilizer and to improve soil's physical, chemical and biological properties. It is commonly prepared by decomposing plant, food waste, recycling organic materials and manure. The resulting m ...

ed along with other degradable matter. Other waste can be included for composting, such as

cut flowers Cut flowers are flowers or flower buds (often with some stem and leaf) that have been cut from the plant bearing it. It is usually removed from the plant for decorative use. Typical uses are in vase displays, wreaths and garlands. Many gardene ...

, corks, coffee grounds, rotting fruit, tea bags, eggshells and nutshells, and paper towels.

Mechanisms for automated sorting

Automation of municipal solid waste sorting process is an active research area. Notable mechanisms for automated sorting include: *

Standardization Standardization or standardisation is the process of implementing and developing technical standards based on the consensus of different parties that include firms, users, interest groups, standards organizations and governments. Standardization ...

of products, especially of

packaging Packaging is the science, art and technology of enclosing or protecting products for distribution, storage, sale, and use. Packaging also refers to the process of designing, evaluating, and producing packages. Packaging can be described as a co ...

which are often composed of different materials, in particular materials hard or currently impossible to either separate or recycle together in an automated way. **

Law Law is a set of rules that are created and are enforceable by social or governmental institutions to regulate behavior,Robertson, ''Crimes against humanity'', 90. with its precise definition a matter of longstanding debate. It has been vario ...

s related to recyclability, waste management, domestic materials recovery facilities, product composition, biodegradability and prevention of import/export of specific wastes. ***Since around 2017,

China China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's most populous country, with a population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and ...

, Turkey, Malaysia, Cambodia, and Thailand have banned certain waste imports. It has been suggested that such bans may increase automation and recycling, decreasing negative impacts on the environment. *

Optical sorting Optical sorting (sometimes called digital sorting) is the automated process of sorting solid products using cameras and/or lasers. Depending on the types of sensors used and the software-driven intelligence of the image processing system, optical ...

** Spectral imaging based sorting *** Systems that use

hyperspectral imaging Hyperspectral imaging collects and processes information from across the electromagnetic spectrum. The goal of hyperspectral imaging is to obtain the spectrum for each pixel in the image of a scene, with the purpose of finding objects, identifyi ...

and algorithms developed via

machine learning Machine learning (ML) is a field of inquiry devoted to understanding and building methods that 'learn', that is, methods that leverage data to improve performance on some set of tasks. It is seen as a part of artificial intelligence. Machine ...

** Near infrared spectroscopy ** X-ray based sorting **

Laser-induced breakdown spectroscopy Laser-induced breakdown spectroscopy (LIBS) is a type of atomic emission spectroscopy which uses a highly energetic laser pulse as the excitation source. The laser is focused to form a plasma, which atomizes and excites samples. The formation of ...

* Eddy current based sorting

By country

Germany Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...

, regulations exist that provide mandatory quotas for the waste sorting of

packaging waste Packaging waste, the part of the waste that consists of packaging and packaging material, is a major part of the total global waste, and the major part of the packaging waste consists of single-use plastic food packaging, a hallmark of throwaway ...

and recyclable materials such as glass bottles. In

Denpasar Denpasar (; Balinese script, Balinese: ᬤᬾᬦ᭄ᬧᬲᬃ) is the capital of Bali and the main gateway to the island. The city is also a hub for other cities in the Lesser Sunda Islands. With the rapid growth of the tourism industry in Bali ...

Bali Bali () is a province of Indonesia and the westernmost of the Lesser Sunda Islands. East of Java and west of Lombok, the province includes the island of Bali and a few smaller neighbouring islands, notably Nusa Penida, Nusa Lembongan, and Nu ...

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

, a pilot project using an automated collecting machine of

plastic bottle A plastic bottle is a bottle constructed from high-density or low density plastic. Plastic bottles are typically used to store liquids such as water, soft drinks, motor oil, cooking oil, medicine, shampoo, milk, and ink. The size ranges from v ...

s or aluminium cans with voucher reward has been implemented in a market.' In

India India, officially the Republic of India (Hindi: ), is a country in South Asia. It is the seventh-largest country by area, the second-most populous country, and the most populous democracy in the world. Bounded by the Indian Ocean on the so ...

, the government inaugurated the

Swachh Bharat Mission Swachh Bharat Mission (SBM), Swachh Bharat Abhiyan, or Clean India Mission is a country-wide campaign initiated by the Government of India in 2014 to eliminate open defecation and improve solid waste management. It is a restructured version of ...

("Clean India Mission") in 2014, a nationwide cleanup effort. Before this national consolidated effort for systematic and total waste management came into common consciousness, many cities and towns in India had already launched individual efforts directed at municipal waste collection of segregated waste, either based on citizen activism and/or municipal efforts to set up sustainable systems. In Ukraine, people are learning to sort garbage. Garbage is sorted in schools and kindergartens in Khmelnytsky. In the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territorie ...

, the

Environmental Protection Agency A biophysical environment is a biotic and abiotic surrounding of an organism or population, and consequently includes the factors that have an influence in their survival, development, and evolution. A biophysical environment can vary in scale f ...

reports that the infrastructure for recycling waste has not kept pace with the rate of waste production.

Globally

In terms of plastic waste sorting and recycling, an estimated 9% of the estimated 6.3 billion tonnes of plastic waste from the 1950s up to 2018 has been recycled and another 12% has been incinerated with the rest reportedly being " dumped in landfills or the natural environment".

References

External links