Waste - Introduction
Waste is defined as unwanted and unusable material that is not needed by the owner, producer, or processor. Humans, animals, other organisms, and all processes of production and consumption produce waste. It has always been a part of the earth’s ecosystem, but its nature and scale were such that the ecosystem could use waste in its many cycles. In fact, there is no real waste in nature. The apparent waste from one process becomes an input to another.
Sources and Types of Waste -
It is the exponential growth of human activities that has made waste a problem to be managed. We are simply producing much more waste than the amount nature can handle.
It is far better to prevent the generation of waste than to produce waste and then try to ‘manage’ it. We cannot simply throw away waste. ‘There is no way to throw away’. What we throw away often comes back to us in a different form. What we dispose of remains in the ecosystem and causes some form of pollution. This pollution can have an impact far away from the point of generation and far removed in time too.
Gaseous waste, which is caused mainly by emissions from vehicles and other sources and caries fine particles of matter, leads to air pollution and smog. When gaseous waste is deposited on land as acid rain, it pollutes the soil and water.
Most disposable wastes are in the form of solids, liquids, or slurries. The main categories of such wastes are the following:
- Waste from the oil industry: Oil spills, oil leaks, water used for cleaning tankers, etc.
- Construction waste: Materials from buildings that are demolished or renovated and materials discarded after completing a building.
- Waste from the extractive industries: Mining, quarrying, and dredging create solid waste and slurries.
- Plastic waste: Thousands of different goods made of plastic, thrown away after use, are everywhere on land and sea.
- Agricultural waste: Mostly organic waste from plants and animals; irrigation water from farms containing fertilizers and pesticides.
- Domestic Waste: Sewage, wastewater contaminated by detergents, dirt, or grease, household garbage, and bulky waste including packaging material, appliances furniture, office equipment, and used cars.
- Factory waste: Solids and effluents from factories of all types. The worst polluters are slaughterhouses, breweries, tanneries, textile, paper and steel mills, and most chemical industries; power plants discharge heated coolant water causing thermal pollution.
- Waste from food processing: Organic solid and liquid waste from discarded food materials.
- Biomedical waste: Originates mainly from hospitals and clinics and includes blood, diseased organs, poisonous medicines, etc.
- E-waste: A more recent form of waste from discarded electronic equipment
- Nuclear waste: Radioactive waste from nuclear plants and the manufacturer of nuclear weapons; remains active and dangerous for thousands of years.
Apart from these regular sources, waste also comes from special events:
- Waste from natural disasters: Rubble from earthquakes, slag and ash from volcanoes, wastes left behind by floods, cyclones and typhoons.
- Waste from wars and conflicts: Apart from dead bodies and destroyed buildings, wars leave behind exploded and live shells, landmines, etc. In some cases, deadly war material has effects lasting decades. Agent Orange, a herbicide, used the in Vietnam War, and depleted uranium in the 1991 Gulf War are examples.
It is very difficult to assess the effects of all types of waste on the environment. We do not know the total amounts, composition, and dispersal of waste. Nor do we have enough scientific knowledge of the long-term impact of most substances that form part of the waste. What is considered non-hazardous today may be declared dangerous tomorrow. In fact, environmentalists feel that we must follow the precautionary principle and treat every chemical or waste as being potentially harmful unless proven otherwise.
Municipal Solid Wastes and Hazardous Wastes
Municipal solid waste is a general term used for the combination of solid, semi-solid wastes generated from household and even commercial activities like various businesses and institutions. Examples include garbage like paper, food waste, plastics metals, rubber, leather, textiles, wood, glass, etc.
Hazardous wastes include substances that are chemically reactive, flammable, explosive or toxic to living organisms. These are substances that can cause serious, irreversible health effects or present a substantial danger to the environment upon exposure. Examples include -
- E-waste with heavy metals like lead, cadmium, and mercury.
- Pesticides like DDT.
- Petrochemicals like benzene (sourced from detergent production), and vinyl chloride(sourced from plastic production).
- Radioactive wastes.
- Dioxin - It is a man-made toxic persistent Organic Pollutant. It is a colourless organic chemical made up of oxygen, hydrogen, carbon and chlorine. About 75 types of dioxin are known. They are distinguished from one another by the arrangement and number of chlorine atoms in the molecule. Dioxin is a by-product formed during the combustion of organic compounds containing chlorine. The main sources of dioxin are herbicide production; burning of plastics; burning of gasoline and diesel in vehicles; copper refining; burning of wood as a fuel etc. It is a potent human carcinogen; that causes skin eruptions; birth defects and digestive disorders.
Both solid wastes and hazardous wastes have grown phenomenally over the years with rapid urbanisation, industrialisation and population growth. As these pose dangers to the environment and human health, scientific disposal of the wastes is essential for human and ecological well-being. As the two categories of waste differ in nature, the waste treatment techniques also vary for both these types of waste.
What is the state of Municipal Waste Generation in the world?
In 2012, the World Bank released a report on global municipal waste generation. The main findings of the 2012 World Bank Report on Waste were:
- Solid waste is the most visible and pernicious byproduct of a resource-intensive, consumer-based economic lifestyle.
- The amount of municipal solid waste is growing even faster than the rate of urbanization. In 2012, 3 billion urban residents were generating 1.2 kg per person per day (1.3 billion tonnes per year). By 2025, this is likely to increase to 4.3 billion urban residents generating about 1.42 kg per person per day of municipal solid waste (2.2 billion tonnes per year).
- The rates of municipal solid waste growth are fastest in China, other parts of East Asia, and parts of Eastern Europe and the Middle East. Back in 2004, China surpassed the US as the world’s largest waste generator. By 2030, China will likely produce twice as much municipal solid waste as the US.
- The collection rates of municipal solid waste range from a low of 41% in low-income countries to a high of 98% in high-income countries.
- As a country’s affluence increases, organic waste generally decreases, while paper and plastic waste increases.
- Low-income countries spend most of their municipal solid waste budgets on waste collection, with only a fraction going toward disposal. This is the opposite in high-income countries where the main expenditure is on disposal.
Why are hazardous and Toxic Wastes Exported?
Many of the industrialized countries have a waste management problem. Since their economies are based on constant growth, development, and consumption, wastes are mounting up and they are running out of suitable space for landfills or dump yards. At the same time, these countries have strict environmental regulations that make waste management expensive.
The most attractive option for industrialized countries is to export the waste to developing countries, where disposal is cheap and environmental regulations are lax. The latter needs the money and the former wants to get rid of the waste. Developing countries do have more space for disposal, but their tropical ecosystems are more vulnerable to the damaging effects of waste. There are many cases of environmental damage caused in developing countries due to improper management of imported toxic waste.
At any time, there are a number of ships carrying toxic prowling on the high. Seas, ready to dump the waste on an unsuspecting poor country. Alternatively, they just dump the cargo somewhere in the middle of the vast ocean.
Waste management has become an international industry and even some industrialized countries like the UK import waste and make money on it. 90% of the hazardous waste generated in the US is exported to Canada.
The 1989 Basel Convention aims to minimize the creation of hazardous wastes, reduce transboundary movements of such wastes, and prohibit their shipment to countries lacking the capacity to dispose of them off in an environmentally sound manner.
How can Solid waste be Recycled?
A good way of dealing with the solid waste problem is recycling, which is the processing of a used item or any waste into a usable form. There is a large recycling industry in the world. In India, we have a thriving, unorganised recycling industry, thanks to the itinerant collector, who buys your old newspaper, bottles, used clothes, utensils, scrap, motor oil etc.
Recycling brings multiple benefits:
- By taking away some of the waste, it reduces environmental degradation.
- As against expenditure incurred on disposing of the waste, we now make money out of the waste material.
- We save energy that would have gone into waste handling and the making of products.
Some specific examples of savings through recycling are :
- When aluminium is resmelted, there is considerable savings in cost. The recycling process, however, is energy-intensive.
- Making paper from waste pulp rather than virgin pulp saves 50% of energy.
- Every ton of recycled glass saves energy equal to 100 litres of oil.
Safe and profitable technologies for recycling paper, glass, metals, and some forms of plastic are available. Biogas can be produced from landfill waste. Paper factories can certainly recycle their waste.
Recycling is not a solution for all waste materials. In many cases, the technologies are not available or unsafe. In other cases, the cost of recycling is too high.
Frequently Asked Questions
Question - What is Waste?
Answer - Waste is defined as unwanted and unusable material that is not needed by the owner, producer, or processor. Humans, animals, other organisms, and all processes of production and consumption produce waste.
Question - What is Waste and its types?
Answer - Waste is any material that is not needed by the owner, producer, or processor. These include urban waste, industrial waste, agricultural waste, biomedical waste and radioactive waste, Plastic waste, and E-waste
Question - What are the sources of waste?
Answer- wastes are produced from different sources such as domestic and household garbage, factory waste, Agricultural and food processing waste and so on.
Question - Why is waste produced?
Answer - Humans, animals, other organisms, and all processes of production and consumption produce waste. It has always been a part of the earth’s ecosystem, but its nature and scale were such that the ecosystem could use waste in its many cycles.
Question - How can we manage waste?
Answer - A good way of dealing with the solid waste problem is recycling, which is the processing of a used item or any waste into a usable form. Recycling brings multiple benefits:
- By taking away some of the waste, it reduces environmental degradation.
- As against expenditure incurred on disposing of the waste, we now make money out of the waste material.
- We save energy that would have gone into waste handling and the making of products.
Question - What is a simple definition of e-waste?
Answer - E-waste is a term used to cover items of all types of electrical and electronic equipment and their parts that have been discarded by the owner as waste without the intention of reuse.
Question - what are 4 examples of e-waste?
Answer - E-waste includes almost any household or business item containing circuitry or electrical components with either power or battery supply- items such as TV appliances, computers, laptops, tablets, mobile phones, white goods (fridges, washing machines, dryers etc.), home entertainment and stereo systems etc.
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